Fixed Prosthodontics Exam 1
(THE VARIABLES) WHICH of the following is FALSE: Increasing the proportion of silica in the investment powder.... a. increaes heat resistance b. increases manipulation time c. increases initial setting time and expansion. d. decreaes comprehensive strength e. rate of setting is UNCHANGED [Wax Investment (3)]
reduces heat resistance. increases manipulation time. increases initial setting time. increases setting expansion. increases thermal expansion. decreases compressive strength. rate of setting is unchanged
A complex amalgam restoration replaces a missing __________ on a molar.
replaces a missing cusp.
[Principles Of Tooth Preparation (25)*most*] _________ is the features of a prep that ENHANCE THE STABILITY of the restoration and RESISTS DISLODGMENT along an axis OTHER than path of insertion (GPT-9). [know]
resistance form
Know from google doc -10. Metal framework design (7): b. What about for an anterior bridge? - what type of connector is used? Rigid or non ridged and what are each of them?
"1. Connectors should have maximum height without impinging the gingival tissue 2. Lingual to contact area (to resist faciolingual flexion) 3. Approximal struts of metal should be continuous with lingual metal collar 4. If vertical depth on bridge is small, connectors should be extended onto occlusal or lingual surface 5. U-Shapped design of connector 6. Linguo-cervical area should be reinforced with metal 7. Anterior bridge with more than one pontic should have lingual strut of metal exted to the surface where space is limited Rigid connectors = cast connectors and soldered connectors Non-Rigid connectors = Key and keyway (5-unit FPD, tilted molar, dovetail or T shaped Key) or split pontic or cross pin and wing."
Read over from google doc - a. How do we prep and how much reduction do we need for a full cast metal and PFM crown?
"1. Occlusal reduction -- use depth cuts and maintain buccal / lingual inclines 2. Buccal / lingual axial reduction -- axial depth grooves parellel to path of insertion --- functional bevel of 45 degrees on functional cusp -- margin should start off as 0.5mm 3. Break proximal contact with thin diamond or needle -- may protect adjacent teeth with matrix band 4. Finishing -- Margin as smooth as glass -- ROUND ALL LINE ANGLES 5. Evaluation Full cast metal crown reductions --- 0.5mm margin --- 1.5mm for funtional cusps --- 1.0mm for non functional cusps (ONLY GAVE US MOLAR INFO) PFM crown reductions --- 1.0mm margin facially --- 0.5mm margin lingually --- 1.2ish facial --- 2.0 incisal --- 1.0-1.5 lingual (ONLY GAVE US ANTERIOR) NOTE --- ANYWHERE THERE IS PORCELIN WE REDUCE MORE THAN ANYWHERE THERE IS METAL ONLY"
Read over from google doc - a. How is it categorized and how does it bond to metal or zirconia
"A ceramic is an inorganic, non metalic, solid -- prepared by heat and subsiquent cooling --- two major componants = refractory crystaline structure (bricks) and glass (mortar). ~~Categorized/classified based on the following~~ 1. Microstructure - Glass, crystalline, or crystaline particles in a glass matrix 2. Composition 3. Principle crystal phase and/or matrix phase 4. Processing method - ex: CAD-CAM milling 5. Firing (fusion) temperature -- ultra low/low (crown and bridge veneer ceramic), med (denture teeth, presintered zirconia), high (denture / fully sintered alumina and zirconia core ceramics) 6. Translucency 7. Fracture resistance 8. Uses or indications 9. Abrasiveness Most popular fabrication technique for metal ceramic = Sintering ------ For all ceramics = Heat pressing; Hard machining; and Hard machining + heat treatment Polycrystalline = no glass componants; much tougher and stronger than glassy ceramics --- Zirconia Predominantly or particle filled glass ceramics (feldspathic) = More glass = less strength but better looking -- silica is a common mix-in" --------------------------- "How it bonds --- 1. Mechanical entrapment (22%) 2. Chemical bonding 51% 3. Compressive forces 26% CHEMICAL BONDING IS THE PRIMARY BONDING MECHANISM FOR METAL Compressive forces -- Many restorations made from metal and porcelain combinations having contraction coefficient differences between 0.5 and 1.0 × 10 −6 /K are known to survive for many years. FOR ZIRCONIA--- There is NO clear evidence of chemical bonding to veneering ceramics and MECHANICAL SEEMS TO BE THE PRIMARY MECH."
From google doc - wax investment: b. Which is used to pour which metal alloy?
"Gypsum = Gold with temps no higher than 1080c (not suitable for high melting point alloys) Cristobalite based investments rapid heat) = 700c High temperature investments are used in the fabrication of alloys prostheses that require stability of the investment at temps between 1000-1200c Phosphate binder (usually with quartx and cristobalite or graphite mixed in) with silicate-bound system used to cast alloys that require times above 1425c Ethyl silicate bonded investments = used for high temp colbolt and nickel chromiam alloys"
Displacement of Gingival Tissues - two methods [Final Impression / Tissue management by Dr. Lamberti (2) ]
(1) "Displacement cords" - Mechanical displacement with non-impregnated cord. • braided (Gingibraid, Van R) • knitted (Ultrapak, Ultradent) - Anesthesia IS necessary. - Chemically impregnated cord in an astringent (Hemodent) They contain aluminum or iron salts that cause ischemia. Aluminum chloride and ferric sulfate are suitable because they cause minimum tissue damage. - Preimpregnated cords with epinephrine should be used with caution. - A loop of retraction cord is formed around the tooth and held tautly with the thumb and forefinger. ------------------- - Placement of the retraction cord is begun by pushing it into the sulcus on the mesial surface of the tooth. - It should also be tacked lightly into the distal crevice to hold the cord in position while it is being placed. ------------------ - The INSTRUMENT MUST be ANGLED slightly toward the root to facilitate the subgingival placement of the cord. - If the instrument is held parallel to the long axis of the tooth, the retraction cord will be pushed against the wall of the gingival crevice, and it will rebound. - Excess cord is cut off in the mesial interproximal area. (2) "Electrosurgery" : • The inner epithelial lining of the gingival sulcus is removed • Access for a subgingival crown margin • Control of postsurgical hemorrhage • Passage of a high-frequency current through the tissue from a large electrode to a small one. - At the small electrode the current induces rapid localized polarity changes that cause cell breakdown ("cutting"). - PRECAUTIONS: Profound local anesthesia is needed => • Not suitable on thin attached gingiva • It should not be used with metal instruments • The electrode should not touch any metallic restoration (can cause pulp damage). • It should not be used on or near patients with cardiac pacemaker or insulin pump
[Diagnosis And Txt Plan (9)] (1) KNOW - What are the four categories for damaged dentitions (due to caries, trauma, or wear) and how do we treat each one? (2) What's the most common reason for need of crown? (3) KNOW how to dx images
(1) - Mild structural damaged dentition (for direct restorations) - Moderate structural damaged dentition = most common reason for needing a crown. (for inlays/onlays, 3/4, or 7/8 crowns indirect restorations). - Moderate to Severe (full crown coverage indirect restorations) - Severe structural damaged dentition(need to extract teeth for removable denture) (2) Defective Restoration (margin, loss of interproximal or hypo- or hyper-occlusal contacts, contour, or internal fit) (3) They can be severe structural damage, moderate, moderate to severe, and severe
[Gypsum & Alginate-5] (1) What will happen to your impression/stone model if you use colder water instead of room temperature? (2)If you don't mix it enough, what will the mixture appear like? (3) If you need to store it, how should you? (4) How do you disinfect it?
(1) Colder water will INC. the working and setting times (similar to effect of high W/P ratio bc too much water). (2) Insufficient mixing results in a grainy mix and poor recording of details. (3) Storage in either air or water results in significant dimensional change. If needed, impression can be stored in 100% humidity (wet towel around it) for 30 minutes prior to pouring. (4) Disinfection can be accomplished by immersion in sodium hypochlorite or iodophors.
[Intro-2] (1) must Know definition of Finish Line & Five major designs of this. (2) must Know definition of axial reduction (3) must Know definition of Incisal/occlusal reduction
(1) Finish Line = MARGIN; the terminal portion of a prepared tooth; the peripheral extension of a tooth preparation; the border of the prep where the prepared tooth structure meets the unprepared surface of the tooth. (imp bc marginal discrepancies disrupt smooth surface thus vulnerable to plaque accumulation leading to secondary caries and micro leakage at the margins). - *Five Major Designs*: 1. Slice-Knife-Edge (less destroy tooth structure; only on axial wall toward tooth is tipped). 2. Bevel 3. Chamfer / Shoulder with a Bevel (adding a bevel to shoulder creates acute edge of metal at margin; adding bevel to chamfer is for use w. metal restoration) 4. Shoulder (all-ceramic restorations only; 90 deg. internal line concentrates stress: coronal fracture). 5. Chamfer (cast metal restorations, acute margin, sufficient thickness and strength, rounded concavity, lower stress concentration within cement film; tho heavy chamfer has large radius internal line angle 90 degree surface for ceramic restorations) (2) Axial Reduction: Normal axial contours preventing periodontal problems. (3) Occlusal Reduction: - Functional Cusp requires a bevel.
[Occlusion And Articulator (10)] if you have steep curve of spee what kind of cusp heights do you need on molars?
shorter
(1) HIGH-GOLD ALLOYS (2) GOLD-PALLADIUM-SILVER ALLOYS (3) PALLADIUM-SILVER ALLOYS (4) GOLD-PALLADIUM ALLOYS (5) PALLADIUM-COPPER ALLOYS (6) PALLADIUM-COBALT ALLOYS (7) BASE METAL ALLOYS [Metal Alloys And Casting (6)] [must know What Are The Components And FUNCTION Of The Alloys]
(1) Gold content between 78% to 87% by weight . Total noble metal content about 97%. Tin, indium, and iron are added for strength and to promote good porcelain bond to metal oxide. Light yellow in color. Excellent hardness, tensile strength, and corrosion resistance. (2) 20% to 30% palladium content . 10% to 15% silver content. Higher elastic modulus and less susceptibility of dimensional change during the porcelain baking when compared to high-gold alloys. Good clinical working characteristics and corrosion resistance. Silver can change the color of porcelain. (3) 50% to 60% palladium, with the most of the balance being silver. Physical and chemical properties are comparable to other noble metal alloys. Good corrosion and tarnish resistance. Can affect the color of porcelain. (4) 50% gold, 40% palladium. Favorable yield strength and hardness. Higher elastic modulus when compared to high-gold alloys. Excellent corrosion resistance. Thermal expansion is incompatible with some higher-expansion porcelains. (5) 70% to 80% palladium. Up to 15% by weight of copper. 9% gallium. High hardness and low elastic modulus. Sag resistance is a contra-indication for large-span fixed partial dentures. (6) 88% palladium. 4% to 5% cobalt by weight. Have high coefficient of thermal expansion. Forms a dark oxide that may be difficult to cover. More susceptible to hot tearing and embrittlement from carbon when no silver is present. (7) Based mostly on nickel and chromium, with a few cobalt- chromium and iron-based alloys available. Corrosion resistance is based on chemical properties
For Full Cast Metal Crown Prep that is completed and perfect, what should be seen from the (1) buccal and lingual aspects? (2) mesial aspect? (3) occlusal aspect? [Tooth Preparation (measurements) (5)]
(1) MD taper (2) - BL taper as well as BL path of insertion - functional bevel - marginal ridge height (3) - concentricity of the prep: even axial walls
(1) RESIN TEETH FOR PROSTHETIC APPLICATIONS (2) MATERIALS FOR MAXILLOFACIAL PROSTHETICS [Acrylic Resins & Temporization (4) ]
(1) Majority of the teeth for prosthetic applications sold in the United States are based on polymethyl methacrylate compositions. Composition is tailored to fit the application. (2) Chlorinated polyethylene is a thermoplastic elastomer created to attempt to overcome the deficiencies of the other materials (synthetic latex, vinyl plastisols, silicone rubbers, polyurethane polymers) and has been used with limited success
Must know what happens when mixed [Acrylic Resins & Temporization (4) ]
(1) Polymerization - During polymerization, volumetric decrease occurs (up to 21% for unfilled acrylic resins, 6% for denture resins, and 1% to 3% for resin composites). - Monomers may be joined together either by addition or condensation reactions. - Most dental acrylics are polymerized by addition polymerization: starting from active center, monomers are activated one at a time and rapidly added together in sequence to form a growing chain. - There are four stages in the addition polymerization chain reaction: 1. Induction = Two processes: activation and initiation. = Period when initiator molecules become energized and break down into free radicals. For the polymerization to begin a source of free radicals is required. Most common initiator is benzoyl peroxide. 2. Propagation (chain growth) 3. Chain transfer 4. Termination
[Gypsum & Alginate-5] For Alignate Hydrocolloids: 1. Powder is mixed with water to obtain a _______. 2. ____ (#) main reactions occur. In the second reaction, _____ is formed into a _______. 3. Manipulation: - Powder should be lightly ______ for aeration. - ___ (#) of powder should be used for ___(#) "measure" of water. - *Always add _____ (water or powder) to the mixing bowl FIRST* [must know] - ___ (time) of thorough mixing for regular setting, and ___ (time) for fast-set. - Set Time is around _____ (time) after mixing.
(1) Powder is mixed with water to obtain a paste => (2) Two main reactions occur: (1) 2Na3PO4 + 3CaSO4 -> Ca3(PO4)2 + 3Na2SO4. (2) Na alginate + CaSO4 (powder) -> H2O Ca alginate + Na2SO4 (gel). (3) Manipulation: - Powder should be lightly shaken for aeration. - One scoop of powder (16g) should be used for one measure of water (38ml). - Always add WATER to the mixing bowl FIRST. - One minute of thorough mixing for the regular setting and 45 seconds for fast-set. Set time is around 3.5 minutes after mixing.
(1) RAPID-HEAT INVESTMENTS (2) HIGH-TEMPERATURE INVESTMENTS [Wax Investment (3)]
(1) While investments based on cristobalite refractory require slow heating, rapid-heat investments can be placed into a furnace preheated to 700oC (2) Used in the fabrication of dental alloys prostheses that require stability of the investment at temperatures in excess of 1000oC to 1200oC. Predominantly have a phosphate binder, with silicate-bound system used to cast alloys that require temperatures above 1425oC
Restorative Contours - Axial Contours: (1) Ideally, Height of contour: on facial surfaces is ____, on lingual surfaces is ______. (*2*) Height of contour on the facial surface of all posterior teeth extends horizontally ______ mm beyond the plane of the root. On the lingual surface of maxillary teethand mandibular first premolars , the height of contour also extends ______mm, but it increases to ____ mm on mandibular second premolars and _____ mm on mandibular molars (d). (3) Emergence profile - convex or concave? (4) Food deflection theory - is it supported here? (5) Overcontouring causes what? (6) Undercontouring causes what? [Wax Patterns [contours & contacts] (4)]
(1) facial - gingival 1/3; lingual - middLe 1/3. (2) KNOW THESE NUMBERS. 0.5; 0.5 mm, 0.75 (man 2pm), 1.0 (man m). (3) Part of the axial contour that extends from the base of the gingival sulcus past the free gingival margin. Concave or flat, never convex. Straight profile in the gingival 1⁄3. [dont confuse- proXimal contacts r conveX; axial emergence profile is concave - think: cave been near to wear axe. ] (4)Food deflection theory: no longer supported • Protection of gingival margin. • Gingival Stimulation. • Self Cleansing contour (5) Overcontouring: inflammatory and hyperplastic change in 4 weeks. (6) Undercontouring: no significant change . Gingival recession possible.
(1) Forces applied to the pontic of a routine FPD are _______. (2) Forces on the pontic of a cantilever fixed partial denture are _______. [Diagnosis And Txt Plan (9)] [imp mentioned twice] tend to tip the FPD or the abutment tooth. transmitted to both abutment teeth.
(1) transmitted to both abutment teeth. (2) tend to tip the FPD or the abutment tooth.
Must know components of acrylic resins [Acrylic Resins & Temporization (4) ]
(Polymers (large macromolecules in chainlike/cross structure capable of virtually limitless configurations) formed from monomers.) Components: (1) MMA =METHYL METHACRYLATE (2) POLY (METHYL METHACRYLATE) (PMMA) - hard resin and VERY stable material.
How is total minimum thickness for anterior PFM crown determined? [Tooth Preparation (measurements) (5)]
(Porcelain Fused to Metal ) Metal coping: 0.3 - 0.5 mm; Porcelain: 0.7 - 1.0 mm
CAD/CAM can be used for?
(is used during treatment) 1. provisional crown fabrication 2. final impression and/or bite registration 3. Form working & opposing cats 4. die trimming, mount casts, & lab rx.
correct thickness for anterior connectors not less than [Metal Framework Design (7)] [know]
*2.5mm width x 2.5mm height* (may decrease to 2.0mm in small single pontic).
[Diagnosis And Txt Plan (9)] What acquired conditions can lead to Structural Damaged tooth, and ultimately require rx for crown treatment? What inherited conditions ""?
*Acquired Condition: Dental Caries or Trauma.* Inherited Condition: Dentinogenesis Imperfecta, Dentine Dysplasia. [examples of functional issues that are reasons for rx crown tx]
If u do a 6 unit fixed partial denture on anterior teeth, which is better: U arch form or straight arch form? [Diagnosis And Txt Plan (9)]
*Anterior Cantilever Effect* - straight / square arch form is better! bc U arch form will put too much force on the terminal (Replacing max. anterior teeth (7,8,9), favorable treatment option is not U shaped arch form because u have too much distance from terminal abutment. If someone is eating an apple, you'll get bending bc amount of taught will be higher. )
Read over from google doc - b. Know how to evaluate abutments. How should they be for crown/bridge?
- 3-unit FPD is ideal more than cantilever. Must have proper angle of insertion (15-20 degrees conical) vertically. If there is drifting, crown should be modified to compensate the drift or orthodontic movements. For pontics, they need to be thick to disperse adequate forces. Pontics should not be thin. If there is a 4-unit FPD, then there must be 1 premolar and 1 molar as pontics
Incidence of complication for single restoration [know]
- All ceramic crown 8% - Post/Core 10% - Conventional single crowns 11% [recall most common complication for single crowns is the need for endodontic treatment ]
[Occlusion And Articulator (10)] How can you tell if the Articulator is Arcon or Non-Arcon? [must know]
- Arcon: Condylar elements in lower member ("mandible"), and condylar Path elements in upper member = Whip Mix (*ours*), Denar. - Non-arcon: condylar element in upper member of the articulator (condylar path stimulating glenoid fosse are attached to lower member) = Hanau
Incidence of complication for FPD - which has more complications: conventional, or resin bonded? [know]
- Conventional FPD 27% - Resin Bonded FPD 26%
Important Properties of Metal Alloys [Metal Alloys And Casting (6)] [nede to know their fxns]
- Due to the small cross section, yield strength is crucial. - Stress controls the minimum allowable dimensions of critical areas. - Elastic modulus affects the flexibility of a metal framework. - Chemical stability affect tarnish resistance, corrosion resistance, and thermal stability. - Biocompatibility.
[Principles Of Tooth Preparation (25)*most*] 1. Marginal Seal - know ranking 2. Seating - know whats the best
- Marginal seal: feather edge and parallel bevel > FULL SHOULDER> 45o shoulder > 90o SHOULDER W. 30o AND 45o BEVEL. (red - know ranking). - Seating: FULL SHOULDER > 45o shoulder >90o shoulder with 45o bevel > feather edge > 90o shoulder with 30o bevel > Chamfer with parallel bevel > 90o shoulder with parallel bevel
[Occlusion And Articulator (10)] 2 Basic Components of Mandibular Movement: ______ is when the body turns around an axis. _______ is when all the point within a body have identical motion.
- Rotation: when the body turns around an axis. - Translation: when all the points within a body have identical motion.
MULTIFUNCTIONAL METHACRYLATE AND ACRYLATE RESINS [Acrylic Resins & Temporization (4) ]
- The backbone of the molecules formed in this system can have any shape, but methacrylate groups are always found at the ends of the chain and at the ends of branching chains. - Bis-GMA resin is an aromatic ester of a dimethacrylate, synthesized from an epoxy resin and a methacrylate. - TEGDMA is blended to reduce viscosity and provide good consistency and manipulation properties. - Urethane dimethacrylates (UDMA) resins comprise any monomer containing one or more urethane groups and two methacrylate end groups.
Which will have a more favorable prognosis - a FPD replacing a maxillary canine, or replacing a mandibular canine? [Diagnosis And Txt Plan (9)]
- replacing a maxillary canine is subjected to more damaging stresses bc forces are directed OUTWARD and pontic lies farther outside the interabutment axis. - replacing a mandibular canine has more favorable prognosis than that replacing a maxillary canine bc the forces are directed INward and the pontic will be CLOSER to the interabutment axis.
Full Cast Metal Crown Prep - Buccal and Lingual Axial Reduction: place the margin concurrently _____ mm in depth. [Tooth Preparation (measurements) (5)] [must know definition of axial reduction]
0.5mm - Less than half the diameter of the diamond bur to avoid 'enamel lip' or J-shaped margin!
St 1. The glass components of ceramic combine together to form amorphous glass gel matrix. St 2. Alumina and Silica are examples of the glass component found in ceramics.
1 is true, 2 is false. [MUST KNOW CRYSTAL VS. GLASS] • The refractory (crystalline) materials in a ceramic body are like the stones in a rock wall "refractory crystalline structure" = Particles of metallic oxides: i.e. aluminum oxide (ALUMINA) & silicon dioxide (SILICA). • The glass component of ceramic bodies is like the mortar between the stones in the wall - The Glass component of ceramics are also composed of Si20 and Al2O3. But, unlike their refractory counterparts, Si20 and Al2O3 do not retain their crystalline identities. The molecules of these components combine together to form AMORPHOUS GLASS GEL MATRIX .
St 1. A full cast metal crown may be indicated if a patient has extensive destruction from caries or trauma. St 2. A full cast metal crown may be indicated if a patient has uncontrolled caries.
1 is true, 2 is false. (don't worry too much on this bc u made up question, but recognize where the diffs are!) • Indications for Full Cast Metal Crown: 1. Extensive destruction from caries or trauma 2. Endo treated posterior teeth 3. Necessity of maximum retention and resistance: short clinical crown or long span FPD 4. Correction of contours is needed - recontouring of axial surface 5. Modification of occlusion 6. Surveyed crown for removable partial denture • Contraindications for Full Cast Metal Crown: 1. Mouth with uncontrolled caries 2. Mouth with untreated perio disease 3. Less than maximum retention necessary: onlay or 3⁄4 crown 4. Esthetic needs
The retainers on secondary abutments will be placed in ______ when the pontics flex, with the primary abutments acting as ______. [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
tension; fulcrums.
Types of Prosthesis used for the replacement missing teeth [Diagnosis And Txt Plan (9)] [red outlined on chart by prof] Write out before test and understand major differences
1) Conventional Tooth-Supported FPD: - posterior span: 2 or fewer. - Incisors: 4 or fewer. - usually has distal abutment but can be used with short cantilever pontic. - abutment alignment: less than 25 deg inclination can be accommodated by preparation modification. - abutment condition good if abutments need crowns. Nonvital (dead) teeth can be used if there is sufficient coronal tooth structure. - Occlusion: favorable loading (magnitude, direction, frequency, duration). - Periodontal Condition: good alveolar bone support; crown-root ratio 1:1 or better; no mobility; favorable root morphology; provides rigid stabilization. - ridge form: moderate resorption; no gross soft tissue defects. . 2) Resin-BOnded Tooh-Supported FPD: - single tooth - possible for 2 incisors. - abutments mesial and distal to pontic. - abutment alignment: less than 15-degree inclination mesiodistally; should be in same faciolingual plane; preparations are not easily modified bc of minimal reduction. - abutment condition: defect-free abutments. Insicor, premolar replacements. - Occlusion: canNOT be used for incisor replacement in presence of deep vertical overlap. - Periodontal condition: No mobility; periodontal splits (w. auxiliary resistance in tooth preparation). - Ridge form: moderate resorption; no gross soft tissue defects. - General Features: well suited for young patients; can be used for replacing molars if masticatory muscles are not well developed.
Abutment Evaluation involves what? [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
1) Crown-Root Ratio 2) Root Configuration 3) Periodontal ligament space
MUST KNOW - What is gypsum products and how do we control properties of gypsum products? 1. What's the water to powder ratio? Should you use cold or hot water (why)? 2. Gypsum products generally refer to the varius forms of _____________. 3. SYNTHETIC gypsum is what? 4. ISO Types 5. Four stages of setting are? 6. The setting reaction causes a ________ in true volume of reactants. Once the mix begins to solidify, an ______________ is observed. [know]
1) For dental stone, we use 30:100 ml/g water to powder ratio => we should use cool water because this increases our setting time, and decreases expansion but has no effect on strength. *Increased temperature decreases setting time* (don't want that). 2) "-Gypsum products generally refer to the various forms of *calcium sulfate (hydrous and anhydrous).* - SYNTHETIC gypsum = by product of the manufacturing of phosphoric acid. -ISO type I - Impression Plaster, ISO type 2 - Plaster, High-strength plaster ------> ISO type 3 - stone, ISO type 4 - Stone, high-strength, low-expansion, ISO type 5 - Stone, high-strength, high-expansion -The four stages of setting (1) fluid, (2) plastic, (3) friable, and (4) cartable [Fill Plate For Candy] -The setting rxn causes a decrease in true volume of reactants. Once the mix begins to solidify, an Isotropic expansion is observed.
What treatment modalities are available for Treatment of Partial Edentulism? [Diagnosis And Txt Plan (9)]
1) Tooth Supported Fixed Partial Denture (FPD): 1a) Conventional Tooth Supported FPD - Plan for short span FPD whether teeth supported FPD(s) or Implants supported FPD(s). 1b) Resin Bonded FPD 1c) Cantilever FPD: Avoid long cantilever bridge (forces on the pontic of cantilever fixed partial denture tend to TIP the fpd or the abutment tooth). 2) Removable Partial Denture (RPD) 3) Implant Supported Fixed Partial Denture (Imp FPD): use dental implants strategically.
1) A Metal inlay can be used to restore ______. 2) Ceramic Inlays can be used to restore _______. 3) An _________ for a maxillary premolar. [Must know restoration types and how to be done] [Diagnosis And Txt Plan (9)]
1) a molar 2) posterior teeth 3) MOD onlay
St 1. Low Water/Powder ratio will result in less microporosties related to residual unreacted water. St 2. Low Water/Powder ratio will increase microporosity related to crystal growth. St 3. Low water/powder ratio (bc not enough water) will result in more bubbles. [Gypsum & Alginate-5] MUST KNOW WHAT VARIABLES CAN AFFECT SETTING PROCESS
1, 2 are true. 3 is false: - Not enough water => more voids as observed under microscope. - Too much water => more bubbles.
Final Impression Technique [Final Impression / Tissue management by Dr. Lamberti (2) ]
1. Anesthesia 2. Provisional restoration and temporary cement removal 3. Probing 4. Gingival retraction 5. Apply adhesive to the tray 6. Material mixing: Load heavy body material into tray; • Light body Material injection into the sulcus covering the entire preparation including margins. 7. Isolation 8. Removal of retraction cords 9. Dry area
Types of Interocclusal Records [Occlusion And Articulator (10)]
1. Centric - CR & MIP 2. Eccentric - Lateral & Protrusive
[Occlusion And Articulator (10)] 3 Mandibular Postitions: 1. Which one is INDEPENDENT Of CONDYLAR position a. CR (centric relation) b. MIP (Maximum intercuspal position) d. VDR (vertical dimension of rest) 2. Which one is INDEPENDENT OF TOOTH CONTACT. a. CR (centric relation) b. MIP (Maximum intercuspal position) d. VDR (vertical dimension of rest) 3. Which one is when MUSCLES ARE MINIMAL? a. CR (centric relation) b. MIP (Maximum intercuspal position) d. VDR (vertical dimension of rest) [[know]
1. Centric Relation (CR): a maxillomandibular relationship, INDEPENDENT OF TOOTH CONTACT, in which the condyles articulate in the ANTERIOR-SUPERIOR position against the posterior slopes of the articular eminences; in this position, the mandible is restricted to a PURELY ROTARY MOVEMENT; from this unstrained, physiologic, maxillomandibular relationship, the patient can make vertical, lateral or protrusive movements; it is a clinically useful, REPEATABLE reference position. 2. Maximal Intercuspal Position (MIP): the complete intercuspation of the opposing teeth INDEPENDENT OF CONDYLAR POSITION, sometimes referred to as the best fit of the teeth regardless of the condylar position. 3. Vertical Dimension of Rest (VDR) or Physiologic Rest Position (PRP): the postural position of the mandible when an individual is resting comfortably in an upright position and the associated muscles are in a state of minimal contractual activity. [CAPS BC UNDERLINED RED]
Restorative Contours - Embrasures should be symmetric to _______ [Wax Patterns [contours & contacts] (4)]
to the bisecting line.. • MDlineangles(1) • Cusplines(2) • Centralgrooves(3)
Anterior FPD design [must know how design should be for anterior bridge - draw a picture!] 1. Correct thickness for anterior connectors is not less than _______ x ______ (may decrease to _____mm in small single pontic). 2. Connectors placed as far _____ to resist faciolingual flexion. a. facially b. lingually 3. Minimum depth of cervical collar is: a. 1mm b. 2mm c. 3mm d. 4mm 4 -7. read it [Metal Framework Design (7)]
1. Connectors should have maximum height without impinging the gingival tissue. - correct thickness for anterior connectors not less than *2.5mm width x 2.5mm height* (may decrease to 2.0mm in small single pontic). 2. Connectors as far as lingually to resist the faciolingual flexion: lingual to contact area 3. Approximal struts of metal should be in corrugated form and continuous with the lingual metal collar. - minimum depth of cervical collar *3mm*. 4. When the occlusogingival depth on the bridge is small , connectors should be extended onto the lingual/occlusal surface. 5. U-shaped connector. 6. High tensile stress can be incurred at the linguocervical area of the retainer. This area must be reinforced with metal. 7. Anterior bridge involving more than one pontic should have the lingual strut of metal extended to the surface where space is limited.
[Occlusion And Articulator (10)] Cusp Placement in Centric
1. Cusp to Marginal Ridge: Type 1 & Type 2. 2. Cusp to Fossa
For PFM , depth cuts should be made using what bur? Incisal depth cuts should be _____mm, and labial depth cuts should be _____. [Tooth Preparation (measurements) (5)]
1. Depth cuts: coarse round or flat end tapered diamond - Incisal > Depth cuts:1.8 mm > Parallel to the unprepared incisal edge - Labial > Depth: 1.2 mm > Incisal portion ): normal facial contour > Cervical portion : long axis or path of insertion
[Principles Of Tooth Preparation (25)*most*] _________ is any irregularity in the wall of a prepared tooth that prevents the withdrawal or seating of a crown or wax pattern; when the divergence exists between the opposing axial wall or wall segments
undercut (affects reTenTion!)
[Principles Of Tooth Preparation (25)*most*] "Marginal Integrity" 1. Guidelines for Margin Design
1. Ease of prep without overextension or unsupported enamel at the cavosurface line angle 2. Ease of identification in the impression 3. Distinct boundary for wax pattern 4. Sufficient bulk of material: to avoid distortion and provide strength; esthetic appearance 5. Conservation of tooth structure. 6. Enamel Lip or J-shaped margin (J-shaped margin is somewhat concave margin)
[Intro-2] - What are the subcategories in prosthodontics? - defn. of fixed prosth? - Treatment Modalities
1. Fixed Prosthodontics = tooth or implant supported. 2. Removable Prosthodontics = tooth or implant or mucosa or combo of tooth or implant and/or mucosa supported prosthesis. 3. Implant Prosthodontics 4. Maxillofacial Prosthetics - Fixed Prosth = The branch of Prosthodon=cs concerned with the replacement and/ or restora=on of teeth by ar=ficial subs=tutes that cannot be removed by the patient. - Treatment Modalities: • Tooth supported crown • Fixed Partial Denture (FPD) • Implant supported crown • Implants supported FPD
the process that created amorphous gel glass from the original silica crystal is known as ________. [Color : Ceramics & Porcelain (7?)] [know crystal vs. glass]
vitrification (red)
REVISED ADA CLASSIFICATION OF ALLOYS FOR DENTAL PROSTHETIC APPLICATIONS [Metal Alloys And Casting (6)] [need to know components and functions of the alloys]
1. High Noble Alloys - total noble content >= 60%, where >=40% is gold. 2. Titanium and Titanium Alloys - titanium content >=85%. 3. Noble Alloys - total noble content >=25%. 4. Predominantly Base Metals - >=25%
Vita Clasic Shade Guide - what does manufacturer recommended as sequence for shade matching? [Color Science (2)]
1. Hue Selection 2. Chroma Selection 3. value Selection (use of second, value-ordered shade guide is recommended: B1, A1, B2, D2,...C4). - value best determined w. comparisons made at arms length => Decreases light, Diminishes cone sensitivity, increases rod sensitivity; Tooth fading first has a lower value. 4. Final Check / Revision
Know from google doc - Impression Materials (1): Know what type we are using and what is the property of it?
we use (BPS). "Alginate which is an elastic and irreversible impression material and a hydrocolloid. BPS is just a procedural system of how to do impressions (Biofunctional Prosthetic System) Normal set alginate working time of 2 mins and setting time of 4.5 mins. (from google) fast set alginate working time of 1.25 mins and setting time of 1-2mins. (from google)"
[Principles Of Tooth Preparation (25)*most*] "Preservation of Periodontium" Which of the following is FALSE? (select all that apply) a. margins should be as smooth and even as possible to prevent plaque from accumulating. b. sub-gingival margin should be exposed for cleansing. c. overcontouring axial wall will make small pocket that is difficult to access with brushing (thus plaque can accumulate). d. Crown margin should be 1mm above alveolar crest, and 2mm above alveolar crest in case of crown lengthing. e. If biological width is violated by the crown, you can get inflammatory response (more common) or bone resorption (less common). f. Equigingival margin placement is AT the crest, and subgingival margin placement is 0.5mm below the crest.
1. Margins as smooth and even as possible (bc pvnt plaque from accumulating!) 2. Exposed for cleansing: supra gingival margin (when supra-gingival margin is exposed, tooth brush can reach it easier). 3. Axial contour: overcontour vs. undercontour [overcontour => makes small pocket where plaque accumulate since tbrush dif. access that area] - enough tooth reduction 4. Biologic width: - crown margin = 2 mm above the alveolar crest - in case of crown lengthening = 3 mm from the bone - defn: total height of connective tissue attachment and extracellular attachment 1 mm each, total = 2 mm. - If biological width is violated by the crown, u can get inflammatory response (more common) or bone resorption (less common) . 5. Margin Placement: - Supragingival - Equigingival: at the crest - Subgingival: 0.5 mm below
Bonding Mechanism (said exam q in lecture) [Metal Framework Design (7)]
1. Mechanical - interlocking between porcelain and metal surface - finishing with stone or air abrasion - bonding agents such as platinum spheres 2. Compressive forces - coefficient of thermal expansion: metal > porcelain 3. Van der Waals forces - attraction of molecules - initiate chemical bonding 4. Chemical - oxide layer: tin, indium, gallium or iron. -------------- Clear separation of porcelain -> bonding failure !
[Occlusion And Articulator (10)] What are the three types of articulators?
1. Non-adjustable = Hinge Articulator - Class 1: vertical position. - Class 2: vertical and horizontal; Rotation around hinge axis. - note: shouldn't be used/not recommended. 2. Semi-adjustable: - Adjustable CG and AG - Condylar path: Straight line - Vertical and horizontal movements 3. Fully adjustable
Three components concerning the Structural Durability of tooth preparation [know everything about tooth preparation!]
1. Occlusal Reduction - inclines duplicated - reSiStance form - avoid shortening. 2. Functional Cusp Bevel - Lack of functional cusp bevel can cause: (1) thin area or perforation in casting, (2) result in over contouring and poor occlusion. (3) over-inclination of the facial surface will destroy excessive tooth structure an decrease reTenTion. 3. Proper Axial Reduction. - inadequate axial reduction can cause either: Thin walls and weak restoration, or bulbous and over-contoured restoration.
The blocks are pressure cast in one piece transparent glass ingots • which prevent the formation of defects (pores, accumulation of pigments, etc.) in the body of the block. 1. ___________ - ensures that the blocks can be easily processed in an intermediate crystalline phase, enabling rapid machining with CAD/CAM systems - leads to the formation of lithium metasilicate crystals 2. ___________________ - forms lithium disilicate crystals, Li2Si2O5 which impart the ceramic object with the final shade and desired high strength [Color : Ceramics & Porcelain (7?)]
1. Partial crystallization (red) 2. Tempering after milling (red)
How to Fabricate a provisional restoration/classification: Whats dif. between prefabricated vs. custom restorations? *Whats the dif between direct and indirect techniques?* What material is used for provisional restorations? [Provisional Restorations (5)]
1. Prefabricated vs custom restorations - Prefabricated forms: metal crown forms, clear celluloid shells, tooth colored polycarbonate crowns. Tooth colored polycarbonate crowns = The mold guide is held adjacent to the cast to select the correct crown size. With the crown on the preparation, a mark is made at a distance from the gingival margin that is equal to the amount by which the crown exceeds the height of adjacent teeth. Excess gingival length that extends beyond the mark is trimmed. The preparation and adjacent teeth are painted with separating medium. • The crown filled with resin is placed onto the prepared tooth. Gingival excess created by the expressed acrylic is trimmed back with a garnet disk until the margin coincides with the imprint of the finish line (arrow). • Occlusion is checked with articulating paper. Axial surfaces are polished. • Temporary cement. • All cement is removed from the gingival crevice with an explorer. 2. Material for Provisional restorations: resins. 3. Direct vs indirect techniques: [know - a. Must have a good general overview - What are the restoration types and how are they made and what can we do with them?] - DIRECT [IN OFFICE] • Done on the actual prepared teeth in the mouth. Needs to be removed from tooth before polymerization (shrinkage). • Risk of acute pulpal inflammation due exothermal reaction and chemical irritation from the free monomer. • Irritants: caries, previous restorations, high-speed cutting on fresh dentin. - Indirect:[ONLAYS, INLAYS, 3/4 CROWNS, 7/8 CROWNS, AND FULL COVERAGE CROWNS - MUST BE SENT OUT TO LAB] • Done outside of the mouth on cast flexible cast. • Advantages: avoid locking into undercuts, less trauma for the pulp • Work can be delegated to auxiliary personnel
Requirements for Provisional Restorations? [Provisional Restorations (5)]
1. Pulpal Protection: Material that will prevent the conduction of temperatures extremes. Well adapted margins to prevent leakage. 2. Protect Tissue - to preclude the forces transferred to a surgical site over the edentulous areas. Evaluate -> Periodontal tissue response 3. Positional stability: The prepared teeth should not be allowed to extrude or drift in any way. Position preservation. 4. Occlusal function: Prevent tooth migration, patient comfort when chewing, excursive movements. 5. Ease of cleaning: Material and contour that will permit the patient to keep it clean. 6. Margins: Avoid over or under extended margins that will cause gingival inflammation -Proliferation. -Recession. -Hemorrhage. Material and contour that will permit the patient to keep it clean. 7. Strength and Retention: Resist the forces to which is subjected without breaking or dislodging from tooth.Remain intact during removal (reuse if necessary). 8. Esthetics: Good appearance, patience acceptance 9. Diagnostic : VDO, Esthetics, Function Guideline : "Blueprint" for laboratory communication
Components of a FPD (read thru to refresh) [must know what is pontic]
1. Retainer: any type of device used for the stabilization or retention of a prosthesis. 2. Pontic: an artificial tooth on a fixed dental prosthesis that replaces a missing natural tooth, restores its function, and usually fills the space previously occupied by the clinical crown. 3. Connector: in fixed dental prosthodontics, the portion of a fixed dental prosthesis that unites the retainer(s) and pontic(s)
Features of a mandibular full metal crown preparation and the functions served by each: 1. Functional cusp bevel provides _______. 2. Seating Groove Provides _______. 3. Planar Occlusal Reduction provides ______. 4. Axial reduction provides _________. 5. Chamfer provides _____. a. marginal integrity & periodontal preservation ** b. structural durability c. retention and resistance; & structural durability d. retention and resistance. e. structural durability [Tooth Preparation (measurements) (5)]
1. Structural Durability 2. retention and resistance 3. structural durability 4. retention and resistance; & structural durability. 5. marginal integrity & periodontal preservation.
• Three types of Stresses - read over to refresh [Metal Framework Design (7)]
1. Tensile stress: the internal induced force that resists the elongation of a material in a direction parallel to the direction of the stresses 2. Compressive stress: the internal induced force that opposes the shortening of a material in a direction parallel to the direction of the stresses 3. Shearing stress: the internal induced force that opposes the sliding of one plane on an adjacent plane or the force that resists a twisting action
What system is used to communicate and compare color? [Color Science (2)]
• *Munsell Color system* (red) • CIE1931XYZ color space • Hunter 1948L,a,b colorspace • *CIE1976 (L*,a*,b*) color space* (red)
PORCELAIN-METAL COMPATIBILITY [Metal Alloys And Casting (6)]
1. Thermal expansion, bond strength, and composition are properties to consider when choosing alloys for PFM restorations. - Thermal expansion is important, with slight mismatch between porcelain and metal desirable. - Porcelain-to-metal bond strength ensures retention of porcelain to the metal both in the oral environment and during thermal processing. - Composition is important because some components can affect the color of the porcelain.
[Occlusion And Articulator (10)] Occlusal Interferences: 1. Centric Interferences 2. Working (LATERAL) Interferences 3. Nonworking (LATERAL) Interferences 4. Protrusive Interferences [must know about LATERAL interference]
1. between MIP and CR => A centric occlusal interference often occurs during mandibular closure between MAXILLARY MESIAL-FACING CUSP INCLINES CONTACT MANDIBULAR DISTAL-FACING CUSP INCLINES, MAKING THE MANDIBLE DEFLECT ANTERIORLY. CLINICAL PRACTICE: SUPINE POSITION TO UPRIGHT [red box] 2. may occur between MAXILLARY PALATAL-FACING CUSP INCLINES and MANDIBULAR FACIAL-facing cusp inclines on the WORKING SIDE. 3. when there is contact between MAXILLARY FACIAL-facing cusp inclines and MANDIBULAR LINGUAL-facing cusp inclines on the NONWORKING side. 4. when distal-facing inclines of maxillary posterior teeth contact mesial-facing inclines of mandibular posterior teeth during a protrusive movement.
[Occlusion And Articulator (10)] Face Bow Transfer RED: What is the correct measurement and landmark for arbitrary hinge axis points? n
• 13mm from posterior margin of triages to canthus. - Anterior reference point: 43mm from the incisal corner of the central or lateral incisor. • Types of Face Bow: 1. Kinematic: true terminal hinge axis 2. Arbitrary: arbitrary hinge axis or approximate point • Ear piece (external auditory meatus) Face Bow: An instrument used to record the spatial relationship of the maxillary arch to some anatomic reference point or points and then transfer this relationship to an articulator; it orients the dental cast in the same relationship to the opening axis of the articulator. Customarily the anatomic references are the mandibular condyles transverse horizontal axis and one other selected anterior reference point.
Sequence of Treatment Plan [Diagnosis And Txt Plan (9)]
• Address Chief complaint • Certain Functional and Esthetics consideration may be dealt with early in the Tx Plan
[Principles Of Tooth Preparation (25)*most*] • Analysis of the geometry of finishing lines for full crown restorations - Shoulder of slightly oversized casting showed the _____ marginal discrepancy. • An evaluation of the marginal adaptation of extracoronal restorations during cementation - beveled margins ________ marginal openings but _____ allow the castings to completely seat.
• Analysis of the geometry of finishing lines for full crown restorations - Shoulder of the slightly oversized casting showed the least marginal discrepancy • An evaluation of the marginal adaptation of extracoronal restorations during cementation - Beveled margins reduced marginal openings but did not allow the castings to completely seat
What should coping design be for single crown or retainer? 1. Thickness of the porcelain veneer = ______ 2. Support of the porcelain veneer - no _________. - rounded ____ degrees butt joint at the junction. 3. KNOW: How much are we going to extend the metal for metal coping? - Thickness of metal coping provides _____. - noble metal alloy thickness? - base metal thickness? 4. Occlusal and proximal contacts - anterior ____ - posterior ______. 5. Extent of the area to be veneered ? 6. KNOW: What are the three facial margins for a PFM crown? - what are the options ? [Metal Framework Design (7)]
1. minimum 0.7 mm; 1.0 - 1.5 mm. 2. Support of the porcelain veneer - No sharp angles and undercuts - rounded 90o butt joint at the junction 3. Thickness of metal coping provides rigidity. For a single crown... want: - *noble metal alloy: 0.3 - 0.5 mm - base metal: 0.2 mm.* [know these numbers!] 4. Occlusal and proximal contacts: - anterior: porcelain - posterior: metal or porcelain 5. Extent of the area to be veneered - Metal occlusal resistant to fracture - Halfway down the lingual incline of the facial cusp 6. Facial margin design: a. Metal collar: any type of finish lines especially on beveled shoulder or beveled deep chamfer b. Metal butt joint: shoulder or deep chamfer c. Porcelain butt or collarless: shoulder or deep chamfer
What factors affect gloss? [know what affects color] [Color Science (2)]
1. refractive index of the material, 2. the angle of incident light and the surface 3. Topography.
[Principles Of Tooth Preparation (25)*most*] 1. ____________ prevents removal of the restoration along the path of insertion. 2. _________ prevents dislodgment of the restoration by forces directed in an apical or oblique direction
1. retenTion [has a T in it so to do with the paTh of inserTion] 2. resistance
[Occlusion And Articulator (10)] *KNOW THIS ALL!* Determinants of Mandibular Movement 1. Posterior determinants are? Are they changeable? 2. Anterior determinants are? Are they changeable? 3. What provides indirect control by dental procedures? 4. _________is mandibular guidance generated by the condyle and articular disc traversing the contour of the glenoid fossa. 5. ________ is the influence of the contacting surfaces of anterior teeth on tooth limiting mandibular movements. 6. The farther anterior a tooth is located, the less the influence of the ______ and the greater the influence of the _____.
1.Posterior determinants (CG): Right & Left TMJ - unchangeable. 2. Anterior determinants (AG): Teeth - changeable by restoration, Ortho, occlusal equilibration - for guidance • Canines with longest and strongest roots • Class III lever • Proprioception 3. Neuromuscular system - indirect control by dental procedures 4. CONDYLAR Guidance: mandibular guidance generated by the condyle and articular disc traversing the contour of the GLENOID fossa. - we cannot change this at all. 5. ANTERIOR Guidance: the influence of the contacting surfaces of ANTERIOR teeth on tooth limiting mandibular movements. - we can change this. 6. The farther anterior a tooth is located, the less the influence of the TMJ and the greater the influence of the anterior guidance (AG).
METAL MELTING - MUST KNOW: How do you melt the alloy before testing it? [Metal Alloys And Casting (6)]
1/3 of new gold alloy (by weight) must be used for each new casting. Care should be taken to avoid alloy contamination. METHODS OF MELTING: 1. Natural gas/ air method (torch) is the most common (at the tip of the blue flame.) 2. Electric resistance, induction, and electric arc melting are also used for gold alloys, cobalt-chromium, and titanium alloys
Fractography: _ _______ fractures initiate from contact damage sites and detach at least part of the veneer from the core. __________ fractures initiate from the occlusal or cementation surface beneath the contact or from the margins or connectors and can split a prosthesis in two. - chipping fractures or throuhg-thickness fractures [Color : Ceramics & Porcelain (7?)]
• CHIPPING FRACTURES (RED) initiate from contact damage sites and detach at least part of the veneer from the core. • THROUGH-THICKNESS (red) fractures initiate from the occlusal or cementation surface beneath the contact or from the margins or connectors and can split a prosthesis in two
[Diagnosis And Txt Plan (9)] Prosthodontic Diagnostic Index (PDI) for Edentulism (partial or complete)
• Class I: Minimally Compromised • Class II: Moderately Compromised • Class III : Substantially Compromised • Class IV: Severely Compromised
Pontics are classified based on what three things? [Metal Framework Design (7)] [know pontics]
• Classification: 1. Based upon mucosal contact a. Mucosal contact: - Saddle or Ridge lap - Modified ridge lap - Ovate - Conical or bullet-shaped b. No mucosal Contact: - Hygienic or sanitary - Modified hygienic 2. Based upon material - Metal and ceramic veneered - Metal and resin veneered - All metal - All ceramic 3. Based upon fabrication • Custom made • Prefabricated - Trupontic - Steele's slot back - Sanitary pontic - Pin-facing pontic - Harmony pontic - Reverse pin-facing.
For PFM crown prep, labial and lingual reduction to margin width of? [Tooth Preparation (measurements) (5)]
3. Labial and lingual reduction 3a) Labial - Coarse round or flattened tapered diamond. - Deep chamfer or rounded shoulder - Marginwidth: 1-1.2mm - In case of subgtingival,0.5mmapical to the gingival crest. 3b) Lingual: - Lingual fossa or concavity (cingulum reduction): football shaped o 1 mm for metal lingual; o 1.5 mm for porcelain lingual - Lingual axial reduction: round end tapered diamond o Depth cuts in the same way as full metal crown o 1 mm reduction; o 0.5 mm for chamfer margin
[Principles Of Tooth Preparation (25)*most*] Axial walls should be how high at taper less than 10 degrees?
3mm
For PFM crown prep, as the lingual margin is completed, extend it _____ally onto the _____ area. [Tooth Preparation (measurements) (5)]
4. Proximal reduction - As the lingual margin is completed, extend it facially into the proximal area so that it can blend with the interproximal margin that was placed earlier. - Facial approach is also used - Transition from facial deep chamfer or shoulder to lingual chamfer should be smooth
[Principles Of Tooth Preparation (25)*most*] height:width ratio of prep should be what?
4:10 or greater.
What Pontics are good for posteriors (not aesthetics)? Which are good for anteriors/aesthetics? Which are not recommended? [Metal Framework Design (7)] [know pontics] a. hygienic b. conical c. ridge lap (saddle) d. ovate
6 Designs of Pontics - see attached image! 1. Hygienic (Fish Belly): - posterior mandibulars (non esthetic zone). - Advantages: good access for oral hygiene. - Disadvantages: poor esthetics, and food entrapment. - indications: Non esthetic zone, or Impaired hygiene. - contraindications: Where esthetic is important, or Minimal vertical dimension. - Materials: All Metal. 2. Modified Hygienic (Perel): - posterior mandible; - more advantages than regular hygienic: Good access for hygiene, Less stress in the connector, Less gold used than hygienic pontic. - disadvantage: poor esthetics. - indications & contraindications: Same as hygienic pontic. - materials: All Metal. 3. Conical: - molars w.o esthetic requirement - Advantage: Good access for oral hygiene. - Disadvantage: Poor esthetics - Indications: Posterior areas where esthetics is minimal concern. - Contraindications: Poor oral hygiene. - Materials: Metal ceramic, All ceramic, All resin. 4. Ridge Lap (Saddle): - not recommended. - advantage: esthetics. - disadvantage: Not amenable to oral hygiene. 5. Modified Ridge Lap: - high esthetic requirement - advantage: Good esthetics. - disadvantage: Moderately easy to clean. - indications: Most areas with esthetic concern. - contraindications: Where minimal esthetic concern exists. - materials: Metal ceramic, All ceramic, All resin 6. Ovate: - very high Esthetic requirement (maxillary anterior teeth and premolars). - advantages: Superior esthetics, Negligible food entrapment, Ease of cleaning. - disadvantages: Surgical preparation, & Not for residual ridge defect. - indications: Desire for optimal esthetics, & High smile lines - contraindications: Patient's unwillingness for surgery, or Residual ridge defect. - materials: Metal ceramic, All ceramic, All resin
4. What is the indication for performing Resin-bonded tooth supported fixed partial denture? A. It requires an abutment both mesial and distal to the edentulous space. B. There has been a severe loss of tissue in the edentulous ridge. C. Patients of advanced age D. An insufficient number of abutments E. Dry mouth patient
A (Old People, Nonvital teeth (w. enough coronal tooth structure), dry mouth, muscular issues, gag reflex bad, unfavorable attitude toward RPD = CONVENTIONAL Tooth-Supported FPD)
10. What is the mechanical consideration of the principles of tooth preparation? A. Retention and resistant B. Preservation of tooth structure C. Preservation of the periodontium D. Marginal integrity E. Preservation of biologic width
A - structural durability (Preservation of tooth structure, periodontium, and marginal integrity = Biological Consideration)
Tissue Health - before taking final impression... [Final Impression / Tissue management by Dr. Lamberti (2) ]
• Control of periodontal disease • Proper contour, margins and surface of provisional restoration • Oral hygiene • Use of Chlorhexidine (Peridex or Periogard)
Which of the following is false about Color Deficiency: a. females have more defects in color vision than males. b. achromatism is complete lack of hue sensitivity. c. dichromatism is sensitivity to two primary hues. d. anomalous trichromatism is sensitivity to all three hues, with abnormality in retinal cones affecting one of primary pigments. e. Dentists should always have their color vision evaluated. If ANY deficiency is detected, a dentist sohuld seek help when selecting tooth shades. [Color Science (2)]
A is answer. Defect in color vision. 8% males, 0.5% females. 1. Achromatism - complete lack of hue sensitivity. 2. Dichromatism - sensitivity to two primary hues. 3. Anomalous Trichromatism - sensitivity to all three hues, with abnormality in retinal cones affecting one of primary pigments *RED: Dentists should have their color vision evaluated. If any deficiency is detected, a dentist should seek assistance when selecting tooth shades.*
Determinants of Mandibular Movements of the (Semi-Adjustable) Articulator are?
• Determinants of mandibular movements = CG and AG. - articulator allows for vertical and horizontal movement. - Can adjust condylar guidance (CG) and anterior guidance (AG).
Why use a nonrigid connector on the middle abutment? [Diagnosis And Txt Plan (9)]
A nonrigid connector on the middle abutment isolates force to the segment of the fixed partial denture to which it is applied. - placement of Nonrigid connector on DISTAL side of retainer on middle abutmant => movement in MESIAL direction will SEAT the key into the keyway. - placement of nonrigit connector on MESIAL side of the middle abutment => MESIAL directed movement will UNSEAT the key.
[Intro-2] Single Restorations
• Full Coverage Restorations: Independent Crown & Surveyed Crown • Partial Coverage Restorations = Inlay, Onlay, 3⁄4 Crown, 7/8 crown, Ceramic Veneer [surveyed crown = preplanned for helping support (Etc) future RPD is an indication for a full cast metal crown.
Final Impression - Disinfection [Final Impression / Tissue management by Dr. Lamberti (2) ]
• Glutaraldehyde 2% 10 min soak (not for polyether) • Iodophor (1:213 dilution) • Chlorine compounds (1:10 dilution of commercial bleach)
What three factors must you consider when doing a tooth prep? A. Biological Consideration B. Mechanical Consideration C. Occlusal Consideration D. Esthetic Consideration
A, B, D ( 3 Factors to Consider When Doing Tooth Prep: 1. Biological Consideration = preservation of tooth structure & periodontium; + marginal integrity. 2. Mechanical Consideration = retention and resistance; structural durability. 3. Esthetic Consideration.)
For a case with dental caries, which type of margin is best? A. Subgingival B. Equigingival C. Supragingival
A. - Indications for subgingival margins 1) Dental caries, cervical erosion, subgingivally extended restoration 2) If the proximal contacts is at or below the gingival crest 3) Additional retention and/ or resistance 4) Root sensitivity not controlled by dentin bonding agent 5) Esthetic restoration to hide the labial margin 6) Axial contour modification
What are the ideal requirements of pontics? [Metal Framework Design (7)] [know pontics]
• Ideal requirements 1. Function 2. Esthetics 3. Patient comfort 4. Easy to clean and maintain 5. Biocompatibility 6. Preservation of underlying mucosa and bone
What occurs to gypsum products when you increase spatulation rate? A. Setting time decreases B. Setting time increases C. Setting expansion decreases and setting time increases D. Setting expansion increases and setting time increases E. Setting expansion decreases
A. (KNOW (TABLE!): Inc Spatulation => setting time decreases, setting expansion increases, no effect on strength, consistency decreases. [IMP*: setting expansion & setting time will ALWAYS be opposite except for vacuum mix: they r both dec])
What occurs to gypsum products when you increase the water temperature? A. Setting time decreases B. Setting time increases C. Setting expansion decreases and setting time increases D. Setting expansion increases and setting time increases E. Setting expansion decreases
A. (KNOW: Inc. Water Temp => dec. setting time, inc. setting expansion, no effect on strength, dec. consistency.)
Bonding Mechanisms for metal ceramic restorations [Color : Ceramics & Porcelain (7?)]
• Mechanical entrapment (~22%) • Chemical bonding (51%) • Compressive forces (26%). - Many restorations made from metal and porcelain combinations having contraction coefficient differences between 0.5 and 1.0 × 10 −6 /K are known to survive for many years.
Commercial Shade Guides [Color Science (2)]
• Most convenient and common method of making shade selections • Guides consist of shade tabs - Metal backing - Opaque porcelain - Neck, body, and incisal color • Select tab with the most natural intra-oral appearance
EXTENDED RANGE (red) shade guides should be used for? [Color Science (2)]
• Most shade guides do not cover all the colors in the natural dentition • Some porcelain systems extend the typical range - Bleached shades - Dentin shades - Custom shade guides. *For all ceramic restorations we have to consider their translucent properties and select the shade of the abutment tooth structure*
How does ceramic/prcelain crown fracture / why does it fail? classification of ceramo/metal failures [Color : Ceramics & Porcelain (7?)]
Adhesive Failure: 1. porcelain-metal interface 2. metal oxide-metal 3. porcelain-metal oxide Cohesive Failure 4. porcelain-porcelain 5. metal oxide-metal oxide 6. metal-metal - notes from google doc: "Could be an adhesive failure OR a cohesive failure Adhesive = Porcelain - metal interface /// Metal oxide - metal /// Porcelain - Metal oxide Cohesive = Porcelain - Porcelain /// Metal oxide - metal oxide /// Metal - Metal - May not have enough Flexural strength (3 unit bridge has much more flexural strength than a 2 unit cantilever bridge) - May not have a high enough Fracture toughness or ""critical stress intensity"" (BASED ON CRYSTALLINE PHASE) which is a measure that describes the resistane of brittle materials to the catastrophic propagation of flaws under stress --- Strength is inversely proportional to the square root of the flow depth within the surface ---- NOTE - HIGHER ESTHETIC CERAMICS ARE GLASSY ; HIGHER STRENGTH CERAMICS ARE CRYSTALLINE Zirconia is special in that it can go through ""transformation toughening"" which means that when there is a crack, it can expand by 3% and basically fill in the crack Chipping fractures and through thickness fractures are exactly what they sound like Voids or inclusions make things brittle (vacuum fired means less porosity) -- fractures usually occur due to defects of post insertion stresses --- Compressive stresses tend to close up flaws, while tensile stresses tend to open them ---- a CRYSTALINE PARTICLE may stop crack propogation Thermal shock caused by uneven heating or cooling may cause a crack --- When re-heating, LEUCITE forms in the glass to make it expand A slow crack may develop due to water molecules"
[Principles Of Tooth Preparation (25)*most*] What luting agents allow for the most resistance?
Adhesive resin > glass ionomer > ZPC > polycarboxylate > ZOE
Read over /know from google doc - Metal Alloys and Casting - a. What is the function of these alloys?
Alloying elements are added to alter the hardness, strength, and toughness of a metallic element, thus obtaining properties not found in a pure metal. ------------------------------------- notes about alloys on the doc: - Noble metals (Ru,Rh, Pd, Ag, Os, Ir, Pt, Au) : defined on the basis of their chemical properties. They will easily react with Sulfer, or sulfides, and be resistant to oxidation, tarnish, and corrosion when you heat them up, do your casting, or soldering. - Base metals (C, Al, Si, Cr, Mn, Co, Ni, Cu, Ga, Mo, Ru, Ta, W) : defined on the basis of their chemical properties. They will not resist tarnish and corrosion that easily. They will have a little oxide that will form which leads to tarnish and corrosion. - Precious metals are defined by cost. Semiprecious is more for jewelers (stuff with lots of Silver). Nonprecious has mostly Nickel and Chromium. - ADA Classification of Alloys and their requirements Slide #8 - High-Gold alloys tend to be light yellow in color due to high amount of gold. Gold-Palladium-silver alloys tend to turn green due to silver content. Palladium-silver alloy tend to be whiter b/c lack of gold and can turn green. Gold-Palladium alloys have a thermal expansion that is incompatible with some higher-expansion porcelains. Palladium-Copper alloys shouldn't be used for large-span fixed partial dentures b/c a low Sag resistance. Palladium-Cobalt alloys are more susceptible to hot tearing and embrittlement from carbon when no silver is present.
AGAR [Impression Materials (1)]
Also known as reversible hydrocolloid. Supplied as a gel containing 12% to 15% agar, 0.2% borax, 1% to 2% potassium sulfate, 0.1% alkylbenzoates. The gel material can be converted to a liquid (sol) by heating. Manipulation requires special equipment and trays. Must be poured immediately upon mouth removal to minimize distortion.
Which would be a superior abutment - maxillary central incisor or premolar? Why [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
Although the root surface area of these teeth is similar, the root configuration of the maxillary premolar with its greater faciolingual dimension, makes it a superior abutment to the maxillary central incisor (b), whose root is essentially circular in cross section.
[Occlusion And Articulator (10)] Normal vs. Pathologic Occlusion [ must know Occlusal Morphology] [in lecture he said exam memorize symptoms of bruxism]
• Normal or Physiologic Occlusion - No symptom - Reflex function of neuromuscular system • Pathogenic Occlusion - stress or emotional tension - Bruxism or clenching inc. • muscle fatigue and pain • chronic headache • localized muscle tenderness • TMJ dysfunction • heavy wear facets • cusp fracture • tooth mobility
Impression Materials
An impression material is "any substance or combination of substances used for making an impression or negative reproduction". Impression is "a negative likeness or copy in reverse of the surface of an object; an imprint of the teeth and adjacent structures for use in dentistry". Impression area is "the surface that is recorded in an impression". Impression materials are converted from a liquid state into either elastic or nonelastic negative replicas of the soft and/or hard tissues of the mouth by physical change, chemical reaction, or polymerization. A cast material is them poured into the impression and upon setting, it produces a positive impression of the tissues
46. Hand mixing alginate over power-driven mix with vacuum causes: A. increases mixing time B. decreases setting expansion C. increases compressive strength D. none of the above E. all the above
Answer A (hand mixing and not using vacuum mix => inc. setting time, inc. setting expansion, dec strength, inc consistency (viscosity is more)).
48. What does PFM stand for? A) Porcelain fused to metal B) Porcelain fusing machine C) Pottery furrowed mount D) Porcelain fitting mechanism
Answer: A
51. Increasing the water/powder ratio A increases setting time B decreases setting time C increases temperature D decreases temperature
Answer: A
54. Ceramic crowns are best suited for what type of teeth? A) Incisors B) Canines C) Premolars D) Molars
Answer: A
50. Statement 1: Hue is the variety of color determined by the reflected wavelength of light, while chroma is the intensity or saturation of hue. Statement 2: Gloss is the relative darkness or lightness of a color, due to the amount of energy it transmits. A. Statement 1 is true, statement 2 is false. B. Statement 1 is false, statement 2 is true. C. Both statements are true. D. Both statements are false.
Answer: A HUE = *variety of color, determined by reflected wavelength of observed light (red yellow green blue and purple) within the VLS (visual light spectrum). In Munsell system, there are 10 hue gradations. VALUE is the relative darkness or lightness of a color (0 =black, 10 = white) = amount of energy an object reflects or transmits. objects of different hues/chroma CAN HAVE THE SAME VALUE. *NATURAL TEETH RANGE FROM 5.5-8.5 value*. Restorations too high in value are easily detected.
53. Name the two major components found in ceramics: A. refractory crystalline structure and glass B. refractory crystalline structure and porcelain C. glass and porcelain D. refractory glass and refractory porcelain
Answer: A [Color : Ceramics & Porcelain (7)] • A ceramic is an inorganic, non-metallic solid prepared by the action of heat and subsequent cooling. • The two major components found in ceramics: refractory crystalline structure & glass
29. Common combinations for fixed prosthodontics A. 7 single crowns + 3 unit FBD B. 9 single crowns + 2 implants crowns C. 8 single crowns + 3 Unit FBD D. 9 single crowns + 2 Unit FBD
Answer: A Common Combinations all sum to 10 (think** 9 is eaten (seven ate nine) so its the one w. implant crown): • 7 single crowns + 3 unit FPD (Teeth or Implant supported) • 9 single crowns + 1 Implant Crown or • 8 single crowns + 2 unit FPD (Teeth or Implant supported)
27. What kind of bridge did we make? A. modified ridge lap B. ridge lap C. hygienic D. floating E. saddle lap
Answer: A ( Modified Ridge Lap = - high esthetics - disadvantage: Moderately easy to clean. - contraindications: Where minimal esthetic concern exists. - materials: Metal ceramic, All ceramic, All resin)
59. What type of water will INCREASE the working and setting times of impression material? A. Cold B. Warm C. Hot
Answer: A (remember: hot water will decrease the setting time!)
8. What are the two factors that determine finish line designs? (choose 2 answers) A. Clinician preference B. Patient preference C. Time constraints D. Biomaterials to be used E. Tooth number
Answer: A and D (*Two factors* for finish line designs = 1. Clinician preference based on 2. defined restorative material that u wanna use.)
16. What is the dentist's role? (Select all that apply.) a. Prevent b. Cure c. Correct d. Improve or at least maintain e. All of the above
Answer: A, C, D (Your Role = Prevent, Correct, Improve or at least maintain. )
20. What are the two components of esthetics? (Select 2 answer choices.) a. Contour b. Retention c. Interproximal contact d. Shade matching e. Resistance
Answer: A, D
58. All of the following are disadvantages of metal crowns EXCEPT: A. Less retention and resistance than partial coverage B. Removal of larger amount of tooth structure than partial coverage C. Adverse effects to pulp and periodontium D. Display of metal
Answer: A. MUST KNOW ABOUT Full Cast Metal Crown : [Tooth Preparation (measurements) (5)] • Advantages: 1. Strong: cylindrical shape 2. Greater retention and resistance than partial coverage 3. To modify the form and occlusion 4. Contact areas can be conveniently developed 5. To allow improved access for teeth with furcation involvement: fluting or barreling. • Disadvantages 1. Removal of larger amount of tooth structure than partial coverage 2. Adverse effects to pulp and periodontium 3. Display of metal 4. Vitality test not feasible
[Occlusion And Articulator (10)] _______ is the static relationship between the incising or masticating surfaces of the maxillary or mandibular teeth or tooth analogues. a. occlusion b. resistance c. retention d. articulation In dentistry, ____________ is defined as the static and dynamic contact relationship between the occlusal surfaces of the teeth *during function.* a. occlusion b. resistance c. retention d. articulation
• Occlusion: the static relationship between the incising or masticating surfaces of the maxillary or mandibular teeth or tooth analogues. • Articulation: in dentistry, the static and dynamic contact relationship between the occlusal surfaces of the teeth during function.
[Principles Of Tooth Preparation (25)*most*] Esthetic Consideration - what types of crowns you should use for esthetics?
• Partial veneer crowns: - 3⁄4 crown • PFM or metal ceramic crowns • All ceramic restorations
60. Which of the following investment materials has an advantage that "provides enough setting and thermal expansion to compensate for the cast-metal contraction or porcelain veneer"? a. phosphate b. silica c. Ethyl d. Rapid-heat
Answer: A. WRITE OUT BELOW - PHOSPHATE-BONDED INVESTMENTS [Wax Investment (3)]: Available as a two-component system (powder and an aqueous solution of stabilized colloidal silica). Ingredients in the powder include powdered ammonium dihydrogen phosphate, calcined magnesium oxide powder, particles of refractory materials (quartz and cristobalite), and other metal oxides. Investments used for the casting of high-temperature alloys and for making dies used in the fabrication of porcelain veneers contain quartz and cristobalite to achieve expansion to compensate for the shrinkage of the cast alloy during cooling. Graphite is found in some of these investments to render them more permeable after burnout and/or to provide a reducing atmosphere. Advantages: - High strength - Provide enough setting and thermal expansion to compensate the cast-metal contraction or porcelain veneer. Disadvantages: - Can't be used with casting temperatures above 1375oC - Can make separation after casting difficult. - When higher expansion is required, more silica liquid is used, which can result in incomplete castings. - Bulk powder can react over time with air moisture, which will change the expansion setting and the ability to set to a strong mass.
52. Zinc Oxide-Eugenol is mainly used for denture impressions in arches with minor to no undercuts and the setting time is shortened by increasing the temperature and or humidity. A.True B.False
Answer: A. ZINC OXIDE-EUGENOL [**THINK ZINC SUNSCREAN WILL STING IF U HAVE ANY CUTS; AND OLD PPL W DENTURES USE ZINC SUNCREAN; HAS 2 COMMERCIALLY AVALIABLE FORMS] [Impression Materials (1)] Mainly used for denture impressions in arches with minors to no undercuts. Commercially available as powder/ liquid or as two pastes (base containing zinc-oxide and accelerator containing eugenol). Setting time is shortened by increases in temperature and/ or humidity. Setting time is accelerated by the presence of water, high humidity, or heat
64. The most common complications for which of the following include: caries on abutment (18%), Need for endodontic treatment (11%), Loss of retention (7%)? a. Resin b. FPD c. Single crowns d. All ceramic crown e. Post/Core
Answer: B
49. Bimanual manipulation which is a component of the techniques for taking an interocclusal record is also known as: a. Fisher's technique b. Dawson's technique c. Reynolds technique d. Creek's technique e. Smith's technique
Answer: B [Occlusion And Articulator (10)] WATCH A VIDEO OF THIS - - Bimanual Manipulation by Dawson: Step 1: supine position with chin up Step 2: stabilize head - rib cage and forearm Step 3: seated comfortably chin up again Step 4: position fore fingers of each hand on the lower border. Step 5: position the thumbs together on the symphysis to form a 'C' Step 6: With very gentle touch, manipulate the jaw to slowly hinges open and close Step 7: After mandible feels like freely hinging, verify by load testing
61. What is the ideal taper of a crown preparation? A. 2 to 3 degrees B. 6 to 10 degrees C. 10 to 20 degrees D. 15 degrees
Answer: B ( 6 - 10 deg. is what we want; 10 - 20 deg. acceptable. *as taper increases, reTenTion decrease*)
24. What is the acceptable degree of taper? a. 1-5 b. 6-10 c. 10-30 d. 30-40 e. 90
Answer: B 6 - 10 deg. is what we want; 10 - 20 deg. acceptable. *as taper increases, reTenTion decrease*
66. Retention prevents dislodgment of restoration by forces directed in an apical or oblique direction A. True B. False
Answer: B (1. RETENTION prevents removal of the restoration along the path of insertion. 2. RESISTANCE prevents dislodgment of the restoration by forces directed in an apical or oblique direction)
19. What is the most common complication for FPD? a. Loss of retention b. Caries on abutment c. Need for endodontic treatment d. Discoloration e. Debonding
Answer: B (Caries on abutment 18%, Need for Endodontic Tx 11%, Loss of Retention 7%). [Secondary Caries => FPD or bridge]
44. What is the advantage of a shoulder margin? A. strongest margin because of right angles B. best asthetics because of less visibility of metal coping C. cheapest D. great for kids E. great for women
Answer: B (memorize the fact; 90 deg makes it more susceptible to stress i think)
21. Which of the following are biological considerations of tooth preparation? (Select all that apply.) a. Retention and resistance b. Preservation of tooth structure c. Marginal integrity d. Structural durability e. Preservation of periodontium
Answer: B, C, E ( 3 Factors to Consider When Doing Tooth Prep: 1. Biological Consideration = preservation of tooth structure & periodontium; + marginal integrity. 2. Mechanical Consideration = retention and resistance; structural durability. 3. Esthetic Consideration.)
40. Preparing a tooth for a metal crown, which tooth surface is reduced first? A) Interproximal B) Facial C) Occlusal D) any tooth surface
Answer: C
42. All of the following are attractive characteristics of dental ceramics except: a. biocompatibility b. long-term color stability c. ability to be formed into imprecise shapes d. wear resistance e. chemical durability
Answer: C
25. What is the ideal occlusal reduction for a gold crown? a. 2 mm b. 1.5-2 mm c. 1-1.5 mm d. 1 mm e. 0.5 mm
Answer: C Occlusal reduction: - Gold crown (full metal): 1 - 1.5 mm (1.5mm for functional cusp; 1.0mm for nonfunctional cusp) - PFM and all ceramic crown: 2 mm of clearance.
35. What are some of the applications of acrylic resins in dentistry: A. teeth whitening B. polishing C. Mouth Guards D. Impression materials
Answer: C (Acrylic Resins are mostly used for what? (application) -> Temporary Restorations / "TEMPORIZATION" (red). Other applications include: Denture bases , Artificial teeth, Tooth restoratives, Cements, Orthodontic appliances)
32. What occurs to gypsum products when you increase the water/powder ratio? A. Setting time decreases B. Setting time increases C. Setting expansion decreases and setting time increases D. Setting expansion increases and setting time increases E. Setting expansion decreases
Answer: C (KNOW: INC W/P => INC setting time (doesn't harden as fast), DEC setting expansion, DEC comprehensive strength, & INC consistency. MEMORIZE THE TABLE! [IMP *THINK*: setting expansion & setting time will ALWAYS be opposite except for vacuum mix: they r both dec])
45. All of the following are true about dental acrylics EXCEPT: A. Dental acrylics usually have a powder and liquid presentation. B. Initiators will start the polymerization process C. Plasticizers prevent undesirable polymerization or setting of the liquid during storage, and increase the working time. D. Cross-linking agents will help the linkage of two different polymer chains
Answer: C - KNOW BELOW - Powder (acrylic polymer/copolymer beads) & Liquid parts: 1. Initiators will start the polymerization process (in the powder) 2. Inhibitors (hydroquinone) prevents undesirable polymerization or setting of the liquid during storage, and increase the working time (in the liquid). 3. Cross-linking agents will help the linkage of two different polymer chains (in the liquid). 4. Plasticizers will reduce the rigidity of a stiff un-cross-linked polymer allowing an increase rate of solvent penetration to the polymer (in the liquid). ......so........... - Powder = Acrilic polymer beads; initiator; pigments; dyes; dyed organic fibers; inorganic particles - Liquid = Monomer; Inhibitor; Accelorator; plasticizer; cross linking agent - Volumetric decrease occurs during polymerization --- 21% for unfilled acrylic resins and 3% for resin compositites (remember shrinkage?)"
_____________ are used in dental porcelain powders because they show an to provide blue-white and yellow fluorescence. [Color Science (2)]
• Rare earth metals (europium, terbium, cerium and ytterbium) used in dental porcelain powders because they show an to provide blue-white and yellow fluorescence.
41. When monomer and polymer are mixed in the proper proportions (usually 3:1 by volume), a workable mass is produced. What are the 5 distinct stages the resultant mass passes through? A. Soft, stringy, spongy, rubbery, stiff B. Stringy, sandy, spongy, rubbery, stiff C. Sandy, Stringy, dough-like, rubbery, stiff D. Soft, sandy, dough-like, rubbery, stiff
Answer: C Acrylic Resins and Temporization (must know what happens when mixed) Polymer-Monomer Interaction: - When monomer and polymer are MIXED in the proper proportions (usually 3:1by volume), a workable mass is produced. - monomers are usually joined together by addition polymerization; sometimes by condensation reaction. - addition polymerization = opening of c-c double bonds and some three atom ring structures. - There are 4 stages: 1. Induction = initiator molecules become energized and break down into free radicals required for polymerization. 2. Initiation = Most common initiator is BENZOYL PEROXIDE 3. AND 4. = Propigation and termination. - *The resultant mass passes through five distinct stages: 1- Sandy 2- Stringy 3- Dough-like 4- Rubbery or elastic 5- Stiff [**THINK ITS LIKE MAKING / BAKING A PIZZA]*
17. What is a treatment option for structurally damaged dentition? a. Implant supported crown b. Tooth supported FPD c. Single restoration d. A and B e. B and C
Answer: C MUST KNOW Tx for Structural Damaged Dention: • Single Restoration • Restoration of Endodontically Treated Dentition
36. Which of the following is NOT a component of Impression compound? A. 40% natural resins B. 7% wax C. 3% phosphoric acid D. 50% filler and pigments E. All are components of impression compound
Answer: C (Should be stearic acid) KNOW: Impression Composition = 40% natural resins, 7% wax, 3% stearic acid, 50% fillers and pigment.
14. Which of the following is NOT an advantage of alginate hydrocolloids? A. inexpensive B. hydrophilic C. high tear resistance D. able to displace blood and body fluids E. pleasant taste
Answer: C - it has a LOW tear resistance which is a disadvantage
Shade Mapping [Color Science (2)]
• Recommended even when good custom shade match exists • Tooth is divided into - Three regions - Nine segments • Each region is matched independently • Further characterizations are sketched on diagram, may include... - Craze lines - Hypocalcifications - Proximal discolorations - Translucency
43. Which light source is best quality for color and shade matching? A. Incandescent light B. Fluorescent light C. Natural daylight, noontime D. Natural daylight, morning and evening
Answer: C. - Natural Daylight. Northern daylight considered the best. Closest to emitting the full spectrum of white light. Used as the standard by which to judge other light sources. CRI close to 100. - Fluorescent Light is Not suitable => It emits high concentration of blue waves. CRI between 50-80. - Incandescent Light is Not suitable for shade matching => It emits high concentration of yellow waves and has a Low color rendering index (CRI). - CRI and Time of Day : • Morning and evening = Shorter wavelengths scatter before penetrating atmosphere; Daylight rich in yellow/orange, lacks blue/green. • Mid-day (hours around noon are IDEAL) = Incident daylight is the MOST balanced within VISIBLE LIGHT SPECTRUM = Full spectrum of colors visible!
30. What is NOT an important consideration when attempting to maximize the durability of a ceramic restoration? A. Using a material with a very high elastic modulus B. Maximizing the thickness of the restoration C. Developing occlusal contacts that broad, not narrow D. Keeping the modulus of rupture as low as possible
Answer: D
56. Which aspects of a tooth preparation contribute to both retention and resistance form? A. Magnitude of dislodging forces B. Geometry of tooth prep C. Physical properties of the luting agent D. All of the above
Answer: D
57. Consistency of alginate is NOT relatedness to A. temperature B. spatulation C. water powder ratio D. speed of impression removal
Answer: D
62. Advantages of a full cast metal crown do NOT include A. strong cylindrical shape B. greater retention and resistance than partial coverage C. contact areas can be easily developed D. no adverse effects to periodontium
Answer: D (Full Cast Metal Crown : [Tooth Preparation (measurements) (5)] • Advantages: 1. Strong: cylindrical shape 2. Greater retention and resistance than partial coverage 3. To modify the form and occlusion 4. Contact areas can be conveniently developed 5. To allow improved access for teeth with furcation involvement: fluting or barreling. • Disadvantages 1. Removal of larger amount of tooth structure than partial coverage 2. Adverse effects to pulp and periodontium 3. Display of metal 4. Vitality test not feasible)
[Occlusion And Articulator (10)] 3 Reference Planes or Axes of mandibular movement: 1. ______ plane is the terminal hinge axis or horizontal plane. Allowing hinge moment or open and close. 2. ______ plane is the saggital axis. Allowing lateral movement. 3. ______ plane is the vertical axis. It also allows lateral movement. 4. KNOW: What is the bennett angle? What is bennett movement.
• Sagittal plane: terminal hinge axis or horizontal axis - Hinge movement or open and close - *Pure rotation up to 20 - 25mm opening* • Frontal plane: sagittal axis - Lateral movement - rotates around this axis when one side of mand. drops down during a lateral excursion: NOn-Working condyle = Orbiting; working condyle = rotating. • Horizontal plane: vertical axis - Lateral movement - In the nonworking condyle, the bennett angle measures angle from *saggital plane* to endpoint of movement of condyle center. It is used in articulators . Bennett Movement: When the mandible moves into *lateral excursion*, the nonworking condyle moves forward and inward while the working condyle will shift slightly in a lateroposterior position.
28. All of the following are properties of impression materials EXCEPT: A. Impression materials are used to register and reproduce the form and relationship of teeth and oral tissues B. Hydrocolloids and synthetic elastomeric polymers are the materials most commonly used to make impressions C. The impression will create a negative reproduction of the tissues, and by filling the impression with dental stone or other model material, a positive cast can be made D. None of the above
Answer: D - Hydrocolloids and synthetic elastomeric polymers are the materials most commonly used to make impressions. - The impression will create a negative reproduction of the tissues, and by filling the impression with dental stone or other model material, a positive cast can be made. - The impression material is usually carried to the mouth by means of a tray (plastic or metal; pre-fabricated or individual). - Desirable qualities: Pleasant odor, taste, and color. Absence of toxic or irritant constituents. Adequate shelf life Economical. Easy to use. Good setting characteristics. Satisfactory consistency and texture. Readily wets oral tissues. Resistance to permanent distortion. Adequate strength. Dimensional stability over temperature and humidity normally found in clinical and laboratory setting. Compatibility with cast and die materials. Accuracy in clinical use. Readily disinfected without loss of accuracy. No release of gas during the setting of the impression or cast and die materials. - Types of Impression Materials: 1. Alginate hydrocolloid (A.K.A. irreversible hydrocolloid) 2. Agar hydrocolloid (A.K.A. reversible hydrocolloid) 3. Elastomeric materials 4. Zinc oxide-eugenol materials 5. Gypsum 6. Compound impression materials
39. What is NOT an important consideration when choosing a cast alloy? A. elongation B. fusion temperature C. noble metal content D. luster E. all of these are correct
Answer: D - Important considerations when choosing a cast alloy: 1. Noble metal content, 2. hardness, 3. yield strength, 4. elongation, 5. fusion temperature.
37. All of the following are NON-elastic impression materials except: A) Impression compound B) Plaster C) Zinc Oxide Eugenol D) Agar
Answer: D - nonelastic = plaster, impression compound, zinc oxide-eugenol (*THINK* PIZ). - elastic = hydrocolloids (AGAR) & non aqueous elastomers (polysulfides, silicones, polyethers)
33. Which of the following is NOT a reason to prescribe crown treatment? A. For comfort B. For esthetics C. For Functional Repair of a Structurally Damaged Tooth D. For a patient who doesn't like amalgam fillings
Answer: D [Diagnosis And Txt Plan (9)] Why do you prescribe Crown Treatment? 1. For Functional 2. For Comfort 3. For Appearance = e.g. peg leg L.I. or Tetracycline Staining
What is a treatment option for partially edentulism? a. Implant supported crown b. Tooth supported FPD c. Single restoration d. A and B e. B and C
Answer: D Tx for Partially Edentulism : • Implant Supported Crown • Tooth supported FPD • Tooth supported surveyed FPD • Implant supported FPD.
34. What are the most common diagnoses in the oral cavity? A. Dental Caries B. Pathological disease C. Periodontal Disease D. A and C
Answer: D ([Diagnosis And Txt Plan (9)] - Most common diagnoses in oral cavity: 1) Dental Caries 2) Periodontal Disease)
[Diagnosis And Txt Plan (9)] Diagnoses in Prosthodontics
• Shade mismatch of existing crown • Illfittingrestoration • Traumafromocclusionduetoexistingrestoration • Worn down dentition • Non restorable tooth • PartialEdentulism • CompleteEdentulism
Phasing Treatment [Diagnosis And Txt Plan (9)]
• Urgent Phase • Control Phase • Re-Evaluation Phase • Definitive Phase • Maintenance Phase
Saliva Control [Final Impression / Tissue management by Dr. Lamberti (2) ]
• Use of cotton rolls and dry-angles to cover the salivary ducts • Use of saliva evacuators • Use of local anesthesia • Prescription of anticholinergics e.g. atropine
Color Temperature is related to the color standard _____________.
• description of the warmth or coolness of a light source • related to the color standard BLACK BODY RADIATION. • reported in degrees Kelvin.
Bonding between zirconia and veneering ceramics [Color : Ceramics & Porcelain (7?)] [PFM (bonding mechanisms)]
• no clear evidence demonstrating the presence of chemical bonding between zirconia and veneering ceramics • mechanical bonding seems to play the major role in the zirconia-to-porcelain integration of zirconia- based restorations • strength of bond depends on: - type of veneering ceramic used (COEmismatch) - number of firings - cooling rate after firing
31. Factors affecting the RETENTION of a tooth preparation include all of the following EXCEPT: a) Geometry of the prep b) Surface area of the prep c) Material that is being cemented d) Margins of the prep
Answer: D **MUST KNOW BELOW** [Principles Of Tooth Preparation (25)*most*] Factors affecting retention = 1. MAGNITUDE of the DISLODGING FORCES: - stickiness of food, surface area force is loaded, and surface texture of restoration. (resistance form may be more crucial here). 2. GEOMETRY OF the tooth PREP: - taper (6 - 10; 10 to 20 is acceptable; 2 to 3 deg for round end tapered) - escape of excess luting agent. - slight undercuts in cylindrical prep preventing the restoration from seating. - More Surface area => more retentive (molar > premolar at the same taper). - stress concentration in luting agent or cement: round occlusoaxial line angle; cohesive failure. [**THINK: FAT ROUND STRESS] - type of preparation: partial vs. full coverage; groove or box; -> limit the paths of insertion. 3. ROUGHNESS OF the FITTING SURFACE of the restoration: - roughen or groove the internal surface of restoration by air abrading w. 50u alumina. 4. MATERIALS being cemented: - casting alloy: base metal > gold w. polycarboxylate. [**THINK: BASE HOLDS DOWN THE FORT SO MORE RETENTION] - core or buildup material: composite vs. amalgam. 5. Film thickness and PROPERTIES OF LUTING AGENT OR CEMENT: - Type: ZPC< glass ionomer< adhesive resin [**THINK: Z IS Z-BEST RETENTION] - Film thickness: uncertain
55. All of the following are true in regard to alginate hydrocolloids except: a. They are easily manipulated b. They can only be used for single casts c. They can be used with stock trays d. They are hydrophobic e. The must be poured immediately
Answer: D. [Gypsum & Alginate-5] Alginates are the most widely used impression material in dentistry. Alginate impression products have acceptable elastic properties to form study casts for treatment planning, monitor changes, and fabricate fixed and removable prostheses. ---------------- Advantages: INEXPENSIVE, Easy manipulation, PLEASANT TASTE, ABLE TO DISPLACE *BLOOD* & *BODY FLUIDS*, Hydrophilic, Easily poured, Can be used with STOCK TRAYS. Disadvantages: LOW TEAR RESISTANCE, Must be poured immediately, LIMITED DETAIL reproduction, Dimensionally unstable, Can ONLY be used for SINGLE CASTS, INCOMPATIBLE W. EPOXY RESIN DIE materials. ------------------ Supplied as powders containing: - Sodium or potassium alginate (12 to 15%) - Calcium sulfate dehydrate (8 to 12%) - Sodium phosphate (2%) - Reinforcing filler (~70%) - Potassium sulfate or alkali zinc fluorides (~10%) - Coloring and flavoring agents
18. What is the most common complication for ALL-CERAMIC CROWNS? a. Loss of retention b. Caries c. Need for endodontic treatment d. Fracture e. None of the above
Answer: D. - Fracture 7% - Need for Endodontic Tx 3% - Loss of Retention 2%)
7. Which of the following is the disadvantage of polyether (Imgpregum) A. Long setting time B. Low stability C. Low tear resistance D. Absorption of water E. Low accuracy
Answer: D. - Imgpregum has a relatively SHORT setting time; good dimensional STABILITY (can be poured more than once ,even the next day), good ACCURACY. The disadvantage if absorption of water (should be stored dry!). (Polyether (Imgpregum): Used for most impressions, except for very long and thin teeth Advantages: - Dimensional stability (can be poured more than once ,even the next day) - Accuracy - Low polymerization shrinkage - Relatively short setting time - Automix available(Pentamix machine) Disadvantages: - Set material very stiff - Absorption of water (should be stored dry) Precautions: - Care not to break the teeth when separating the cast - Block undercuts - Care for perio involved teeth)
Glaze, Glazing [Color : Ceramics & Porcelain (7?)]
• to cover with a glossy, smooth surface or coating • the final firing of porcelain in which the surface is vitrified and a high gloss is imparted to the material • prevents leakage of water • SEALS a porous surface Natural glaze—A superficial layer on a ceramic-ceramic or metal-ceramic prosthesis formed by heating a dental porcelain to form a smooth glassy layer. Overglaze — A coating of glass formed by fusing glaze particles on a ceramic surface.
65. Impregum is an example of a polyether rubber impression material. Which of the following statements about polyether rubber impression materials is FALSE? A. Base paste contains a low-molecular-weight polyether with ethyleneimine terminal groups, along with fillers and plasticizers B. Catalyst paste contains an aromatic sulfonic acid ester plus thickening agents and fillers C. Equal amounts of base and catalyst should be mixed rapidly for up to 45 seconds D. Working time is 2.5 minutes and setting time is 4.5 minutes E. Impression should be poured within one hour to minimize distortion and is stable for up to one week
Answer: E KNOW BELOW - POLYETHER RUBBER [Impression Materials (1)]: High stiffness. Short working time. Available in low, medium, and high viscosities. Composition: Supplied as two-paste system> - Base paste contains a low-molecular-weight polyether with ethyleneimine terminal groups, along with fillers and plasticizers. - Catalyst paste contains an aromatic sulfonic acid ester plus thickening agents and fillers. Manipulation: - Similar to polysulfides and silicones. - Equal amounts of base and catalyst should be mixed rapidly (30 to 45 seconds). - Working time of 2.5 minutes and setting time of 4.5 minutes. - Wait at least 1 hour prior to pouring impression. - Dimensionally stable for up to 1 week
6. Which of the following is NOT part of Okeson's description of optimum occlusion? A. in centric, solid and event contact on posterior teeth, slightly lighter contact on anterior teeth B. in lateral excursive movement, working contacts disclude non-working teeth C. in protrusion, anterior teeth disclude posterior teeth D. occlusal forces are along the long axes of the teeth E. in a reclining position, posterior teeth contact more heavily than anterior teeth
Answer: E - should say UPRIGHT position, not reclining. MUST KNOW ABOUT Optimum Occlusion By Okeson: 1. In centric, solid and even contact on the posterior teeth; slightly lighter contact on anterior teeth 2. In lateral excursive movement, working contacts (preferably canine) disclude nonworking teeth. 3. In protrusion, anterior teeth disclude the posterior teeth. 4. Occlusal forces are along the long axes of the teeth. 5. In an upright posture, posterior teeth contact more heavily than do anterior teeth.
47. What is included in the criteria for a successful provisional restoration? A. interproximal contact area B. internal fit/marginal integrity C. occlusion/occlusal anatomy D. contour/embrasures E. Esthetics F. all of the above
Answer: F MEMORIZE the FIVE Criteria for a Successful Provisional Restoration [Provisional Restorations (5)] 1. Interproximal Contact Area 2. Internal Fit / Marginal Integrity 3. Occlusion / Occlusal Anatomy 4. Contour / Embrasures 5. Esthetics ********** -Smooth -No voids/pits -Sealed margin - Resistance /retention form - Ideal occlusal contact -Natural tooth contour and anatomy. -Closed inter-proximal contacts -Modified ridge lap pontic design.
63. Porcelain Fused to Metal crowns are indicated in all of the following situations EXCEPT: A.Esthetics B.Long Span Anterior FPD C.Young patients D. Endo treated posterior teeth
Answer:C MUST KNOW BELOW - Porcelain Fused to Metal Crown (Metal Ceramic Crown) [Tooth Preparation (measurements) (5)] Indications 1. Typical indications for full metal crown AND 2. Esthetics 3. Long span anterior FPD - metal ceramic vs all ceramic 4. Surveyed crown for RPD - metal ceramic vs all ceramic. • Contraindications 1. Presence of active caries and untreated periodontal disease 2. When more conservative solution is feasible 3. Young patients: high risk of pulp exposure
[Occlusion And Articulator (10)] Device stimulating mandibular movements is called?
Articulator
Common combinations for fixed prosthodontics A. 7 single crowns + 3 Implant crowns B. 9 Single crowns + 1 implant crown C. 8 single crowns + 2 unit FPD D. 9 single crowns + 2 unit FPD
B ( Common Combinations all sum to 10 (think** 9 is eaten (seven ate nine) so its the one w. implant crown): • 7 single crowns + 3 unit FPD (Teeth or Implant supported) • 9 single crowns + 1 Implant Crown or • 8 single crowns + 2 unit FPD (Teeth or Implant supported))
5. What is the name of the crown that is pre-planned to assist, retain, or support a future RPD? A. Ceramic crown B. Surveyed crown C. Partial crown D. RPD crown E. This type of treatment does not exist
B - surveyed crown for future RPD is an indication for a full cast metal crown.
13. Which one is not considered criteria for the conventional tooth-supported fixed partial denture? A. The patient has exaggerated gag reflex B. Young patients C. Abutment alignment is less than 25-degree inclination D. The presence of mandibular tori E. Good oral hygiene
B. (YOUNG PATIENTS = RESIN-BONDED, TOOTH-SUPORTED FPD => can be used for replacing molars if mastication muscles are not well developed). CRITERIA FOR CONVENTIONAL TOOTH-SUPORTED FPD = Dry Mouth (high cases Risk), muscular discoordination ordination, madnibular tori, palatal soft tissue lesions, large tongue, exaggerated gag reflex, unfavorable attitude toward RPD, patient can't cope with aging or tooth loss, favorable opposing occlusion (removable prosthesis or periodontically weakened natural dentition may permit FPD in less than optimal situations), must be within dentist's skills
Which of the following is NOT a type of crown we discussed? A. Full Cast Metal Crown B. Ceramic-Ceramic Crown C. All Ceramic Crown D. Porcelain Fused to Metal Crown
B. (Types of Crowns: 1. Full cast metal crown 2. All ceramic crown 3. (PFM) Porcelain Fused to Metal Crown)
9. At least how much dentin should be between the pulp and preparation? A. 0.5mm B. 1mm C. 1.5mm D. 2mm E. 2.5mm
B. Preservation of tooth structure from Pulp Damage => dentin thickness at least 1mm.
Which of the following is correct order for Step-By-Step Procedure for Porcelain Fused to Metal Crown for Anterior teeth: a. Incisal Reduction, Labial and Lingual Reduction, Proximal Reduction, Depth Cuts (incisal and labial), Finishing, Evaluation. b. Depth Cuts (incisal and labial), Incisal reduction, labial and lingual reduction, proximal reduction, finishing, evaluation.
B.. • Step-by-StepProcedureforAnteriorteeth 1. Depth cuts: incisal and labial 2. Incisal reduction 3. Labial and lingual reduction 4. Proximal reduction 5. Finishing 6. Evaluation
THE VARIABLES Modifying agents added to investment material [Wax Investment (3)]
Boric acid, soluble halide salts of alkali or alkaline earth metals are added to increase thermal expansion. Alkali or alkaline earth metals form a continuous "skeleton" that resist overall shrinkage. Presence of modifiers will affect the strength of the investment.
St 1: For preparing a tooth for crown, 10 to 20 degree taper is NEVER acceptable. St 2: As you increase taper, retention increases.
Both are false. - 6-10 deg. is what we want; 10-TWENTY (NOT thirty!) is acceptable => MAX 20 degrees acceptable! - As taper increases, reTenTion DECREASES.
[Gypsum & Alginate-5] Both ____ and ______ are products of partial dehydration of gypsum
Both plaster and stone are products of partial dehydration of gypsum. Differences in properties result from differences in the physical nature of the powders.
What occurs to gypsum products when you use vacuum mix instead of by hand? A. Setting time decreases B. Setting time increases C. Setting expansion decreases and setting time decreases D. Setting expansion increases and setting time increases E. Setting expansion decreases
C ([IMP: setting expansion & setting time will ALWAYS be OPPOSITE, EXCEPT for vacuum mix => they r BOTH dec])
12. For a routine procedure, which type of margin is best? A. Subgingival B. Equigingival C. Supragingival
C is answer.
In dentistry, we mostly use Acrylic Resins for? a. mouth guards b. denture bases c. temporization d. orthodontic appliances
C. (Acrylic resins are mostly used for TEMPORARY RESTORATIONS ("temporization") [red]. - OTHER applications = denture bases, artificial teeth, tooth restoratives, cements, orthodontic appliances)
From google doc - Metal Alloys and Casting - know CLEANING & FINISHING STEPS
Cleaning and Finishing steps: Green stone > brownie > tripole > greenie > red rouge > supergreenie
The main features in a natural tooth that must be produced in dental porcelain (or an esthetic restorative material) are? [Color Science (2)]
Color, Translucency, Texture
Zirconium dioxide (ZrO 2 ) (a.k.a ' zirconia') [Color : Ceramics & Porcelain (7?)] [know: main crystals found in porcelain (leucite, lithium disilicate, zr) - strength, esthetics]
• white crystalline oxide of zirconium • a polymorphic material that occurs in *three different forms depending on temperature*: Cubic (beyond 2370 deg C, tetragonal (Y-TZP) above 1170 deg C, and monoclinic at room temp). • can be partially stabilized by adding small amounts of stabilizers ~ *'doping'*: - *3-5% volume increase producing cracks a reduction in strength and toughness* -> zirconia *transformation toughening*. • Many Y-TZP products are available in dentistry for CAD-CAM processing to be milled: 1. in the green (compacted) state, 2. in a partially sintered state 3. in the fully sintered state
[Gypsum & Alginate-5] (1) When taking an Alignate impression, your working or setting time isn't correct, what could have caused this? (2) You took another impression, but it came out looking distorted. Which of the following may have caused the distortion? a. movement of tray after material has set. b. remoal of impression at correct time. c. storage of impression after removal in dry room. d. storage of impression after removal in moist environment and waiting short time before pouring. (3) So you take even another one, and it has tears in it! Which of the following may have caused the tearing? a. removal of impression from mouth at correct time. b. removed the impression with caution and not quickly enough. c. water-powder ratio proportional by instructions. d. undercuts e. adequate amount of material. (4) Fill in planks about the following problems: - Loss of detail can be related to _____. - Consistency is related to (1) ______, (2) ________, and (3) ________. ** - Porosity can be related to incorrect _________. - Poor stone surface is related to an ___________. a. incorrect spatulation b. water-powder ratio, water temperature, spatulation c. extended period of contact between set gypsum and alginate (separation should occur between 45-60 min after pouring). d. premature removal from the mouth
Common Problems: (1) Improper... water temp (ideal btwn 65-75 F), Spatulation, Water-Powder Ratio, & STORAGE OF THE ALIGNATE POWDER. (2) Distortion - movement of the tray during setting of the material - premature removal of impression - improper storage of impression after removal - length of time between impression making and pouring. (3) Tearing: - premature removal from the mouth - speed of impression removal - incorrect water-powder ratio - undercuts - not enough material (4) - Loss of detail can be related to premature removal from the mouth. - Consistency is related to (1) water-powder ratio, (2) water temperature, and (3) spatulation. - Porosity can be related to incorrect spatulation. - Poor stone surface is related to an extended period of contact between the set gypsum and the alginate (separation should occur between 45 to 60 minutes after pouring)
[Diagnosis And Txt Plan (9)] Know - What are the PDI (Prosthodontic Diagnostic Index) diagnostic criteria for Complete Edentulism? What are the PDI diagnostic criteria for Partial Edentulism?
Complete Edentulism: 1. Tooth Condition 2. Occlusal Scheme Partial Edentulism: 1. location and extent of edentulous area. 2. condition of the abutment teeth. 3. occlusal scheme 4. residual ridge.
______ is commonly used to restore Class III and Class V lesions on anterior teeth. [Must know restoration types and how to be done] [Diagnosis And Txt Plan (9)]
Composite Resin
PHYSICAL PROPERTIES OF DENTURE BASE RESIN [Acrylic Resins & Temporization (4) ]
Critical to the fit and function of the prostheses. Characteristics of interest include polymerization shrinkage, porosity, water absorption, solubility, processing stress, and crazing. (1) POLYMERIZATION SHRINKAGE: Polymerization of methyl methacrylate to polymethyl methacrylate causes a density change from 0.94 to 1.19 g/cm3. When conventional heat-activated resin is mixed at the suggested powder-to-monomer ratio, the volumetric shrinkage should approximately 7%. In addition to volumetric shrinkage, linear shrinkage should also be considered. (2) POROSITY: Results from the vaporization of unreacted monomer and low- molecular-weight polymers. Likely to develop in thicker areas, but may not occur throughout the affect resin segment. Can also be caused by inadequate mixing of powder and liquid. Inadequate amount of material, not enough pressure during flasking, and air entrapment will also produce voids in the mass. (3) WATER ABSORPTION AND SOLUBILITY: PMMA absorbs small amounts of water when place in an aqueous environment. An estimated 1% increase in weight produced by water absorption leads to a linear expansion of 0.23%. Processing method may have an influence on the linear expansion, but the clinical significance is negligible. Denture base resins are virtually insoluble in the oral cavity. (4) PROCESSING STRESSES AND CRAZING: With a natural dimensional change, the affected material sustains internal stresses. Stresses are produced as a result of thermal shrinkage. Although dimensional changes can occur during relaxation of processing stresses, these changes generally do not cause clinical difficulties. It can produce small surface flaws or microcracks (crazing). Crazing is evidenced by small linear cracks that appear to originate at the denture's surface. (5) STRENGTH: Strength is dependent on composition of the resin, processing technique, and conditions presented by the oral environment. One of the most important factors in determining the resin strength is the degree of polymerization ( inc. polymerization, inc. strength). (6) CREEP: Creep is defined as "to change shape permanently from prolonged stress or exposure to high temperatures". Denture resins display viscoelastic behavior. Under sustained load, the material may exhibit deformation with both elastic (recoverable) and plastic (irrecoverable). If the load is not removed, additional plastic deformation can occur over time
Code for Metal Ceramic Crown most commonly used on clinical floor? Code for Metal Ceramic Bridge most commonly used on clinical floor? [Diagnosis And Txt Plan (9)]
Crown - D2752 (Noble Metal). Bridge - D6752 (retainer noble metal)
[Final Impression / Tissue management by Dr. Lamberti (2) ] St 1. Polysulfide polymer is an impression material currently used mostly for fixed dentures and partials. St 2. We don't use polysulfide polymer that much because it has an unpleasant odor and may require a custom tray to minimize contraction of polysulfide polymerization. St 3. Polysulfide Polymer has a high tear strength. Materials: Polysulfide Polymer
Currently used mostly for REMOVABLE dentures and partials Advantages: - High tear strength - Easier to pour than other elastomers - Low cost Disadvantages: - Messy - Unpleasant odor - Long setting time - Stability only fair - Humidity and temperature reduce working time Precautions: - Pour within 1 hour - Use of a custom tray to minimize the contraction of polysulfide polymerization
What is included in the criteria for a successful provisional restoration? A. Marginal ridge B. Masticatory Muscle functioning C. Material Type D. Contour / Embrasures E. Gingiva
D ( 1. Interproximal Contact Area 2. Internal Fit / Marginal Integrity 3. Occlusion / Occlusal Anatomy 4. Contour / Embrasures 5. Esthetics)
What are some of the applications of acrylic resins in dentistry: a. polishing b. teeth whitening c. impression materials d. artificial teeth
D (Acrylic resins are mostly used for TEMPORARY RESTORATIONS ("temporization") [red]. - OTHER applications = denture bases, artificial teeth, tooth restoratives, cements, orthodontic appliances)
11. Which of the following INCREASES setting time? A. More spatulation B. Warmer water temperature C. Low water to powder ratio D. Hand mixing (compared to vacuum) E. All of the above increase setting time
D (inc temp decreases setting time; less water used will decrease setting time (hardens faster); using the vacuum will decrease setting time) (MORE SPATULATION => Dec setting time & consistency. Inc expansion. No effect on strength.)
22. The pulp chamber: a. Increases more facio-lingually than occluso-gingivally with age b. Decreases more facio-lingually than occluso-gingivally with age c. Increases more occluso-gingivally than facio-lingually with age d. Decreases more occluso-gingivally than facio-lingually with age e. Doesn't change with age
D is answer. "Preservation of Tooth Structure" - geometry of pulp chamber = • Check with radiograph • Decrease w. age: more occlusogingivally than faciaolingually (OLD PEOPLE HAVE CHOMPED A LOT IN THEIR LIFETIME).
For teeth, under ________, objective measurements using the CIELAB system showed: Values for L*: 60-95 range (0=black and 100=white). a** scale: -2 to 10 range (measures red-green scale). b* scale: 8 to 25 range (measures yellow- blue). [Color Science (2)]
DAYLIGHT 5000K LIGHTING (red)
Clear Template Fabrication provisional [Provisional Restorations (5)] read over... whats major differences between direct and indirect techniques?
DIRECT IS DONE IN MOUTH] • Diagnostic Wax up of the tooth to be prepared/temporized. Impression of the cast with wax-up and pour cast in fast setting stoneTrim the cast and open a hole through the cast(mid palatal or mid lingual). • A clear temporary splint vacuum forming material is used (0.020-inch-thick resin). • The heating element is turned on, resin sheet is heated. The frame is pulled down over the perforated stage of the vacuum forming machine.The plastic is cut to remove the template from the diagnostic cast.Excess is trimmed from the periphery of the template. *Indirect*: • Upon completion of the prepared tooth, an alginate impression is taken. • Alginate impression poured with Using Mach-2 Die silicone • Fabricate flexible die silicone cast • The acrylic resin is mixed or the Tuff Temp resin material is used to fill the clear template on the prepared tooth. • Rubber bans are wrapped around the template and flexible cast. • If acrylic resin used, wait for polymerization or accelerate with hot water or pressure cooker • Tuff temp material: Light activated • The provisional is easily removed from the flexible cast. • The excess is trimmed down to the margins, using pineapple acrylic burs, discs are used to open the proximal embrasures, The pontic is trimmed to widen the embrasures and create cleanable contours. • Once all excess is trimmed down to the margins, evaluate for voids, defects, open margins and interproximal open contacts that may require adding material or relining. • The marginal fit and occlusion of the provisional are checked in the mouth. Adjustments are done if necessary. • The provisional is polished with pumice and cemented with temporary cement. • An explorer and floss is used to remove cement from the gingival crevice and the inter proximal region. *Direct*: Direct: done on the actual prepared teeth in the mouth. -Make sure margins are well adapted -Occlusion -Cementation • RELINE?? • Hollow the temporary restoration (shell) • Loose fit on the preparation intraorally• Fill the temporary crown with material • Insert intraorally
The Thicker the thickness of pontic, what happens to the deflection? [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
Decreases. - Increase thickness of pontic by 1/2 => Inc. Deflection 8x.
The longer the span length pontic/bridge what happens to the deflection? [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
Deflection increases: - 2x span length of pontic => inc. deflection 8x. - 3x span length of pontic => inc. deflection 27x.
Which is more fluorescent - dentin or enamel? Does more fluorescent mean higher or lower chroma? [Color Science (2)]
Dentin! Dentin contains a greater amount of UV photosensitive organic pigment than enamel and is three times more fluorescent • The more the dentin fluoresces, the lower the chroma
Tooth Color is mainly determined by color of enamel or dentin? [know] [Color Science (2)]
Dentin. Enamel plays a minor role in scattering at bluish wavelengths (may transmit about 70% light through a 1mm thick section), but DENTIN IS WHAT MAINLY DETERMINES TOOTH COLOR (dentin transmits not much more than 30 % light on a 1 mm thick section). - Challenges: A tooth is a multilayered structure of varying thickness, opacities and optical surface characteristics. Color transitions from cervical to incisal, mesial to distal, and labial to lingual => Variety in thickness of enamel and dentin, & Variety in translucency/opacity of enamel and dentin
• The determination of the nature of a disease • Identification of problems and understanding the needs of the patient
Diagnosis [Diagnosis And Txt Plan (9)]
[Diagnosis And Txt Plan (9)] Say your patient's dentition is structurally damaged. You want to diagnose their coronal tooth structure - what are the classifications?
Diagnosis of Coronal Tooth Structure: • Mild: Sufficient retention is provided after tooth preparation for a Direct Restoration • Moderate: Sufficient retention is provided after tooth preparation for an In-Direct Restoration i.e. Inlay or Only or 3⁄4 Crown or 7/8 Crown • Moderate to Severe: Sufficient retention is provided after tooth preparation for a Full Coverage Restoration based on the selected restorative material. • Severe: Insufficient retention is provided after tooth preparation
PFM prep seems to be done. What should vertical and horizontal gap sizes be between incisal edge of your prep and opposing tooth? [Tooth Preparation (measurements) (5)]
Don't wanna contact opposing arch. Vertically: 2mm space. Horizontally: 1.5mm space
All of the following are elastic impression materials except: A) Agar B) Polysulfides C) Silicones D) Polyethers E) Impression Compound
E (- nonelastic = plaster, impression compound, zinc oxide-eugenol (*THINK* PIZ). - elastic = hydrocolloids (AGAR) & non aqueous elastomers (polysulfides, silicones, polyethers))
[Diagnosis And Txt Plan (9)] Process for Diagnosis and Treatment Plan starts with _________.
Examination: • Identify Patient's chief complaint • History: all necessary information concerning the reason for seeking treatment • Examinations: Extraoral and Intraoral • Mounted Diagnostic Casts on a semi-adjustable articulator • FMX and/or Panoramic Radiograph
What is NOT an important consideration when choosing a cast alloy? a. Noble metal content B. hardness c. yield strength d. elongation e. fusion temperature f. all of these are correct
F
Why brittle? [Color : Ceramics & Porcelain (7?)] [know why is porcelain a brittle material]
Fabrication defects: - voids or inclusions generated during sintering: air firing, vacuum firing. - Vacuum Firing Reduces Porosity, Increasing Strength, Translucency. ------------ 1) Surface Cracks: • induced by machining or grinding • Size ranges from 20 to 50 microns • Crack propagation theory: • "As the crack propagates through the material, the stress concentration is maintained at the crack tip, until the crack moves completely through the material, or until it meets another crack, a pore , or a CRYSTALINE PARTICLE (red), which reduces the localized stress." *COMPREHENSIVE STRESES TEND TO *C*LOSE UP FLAWS* TENSILE STRESSES *O*PEN-UP FLAWS* (red) . 2) Thermal Shock: • caused by uneven heating or cooling • crown's surface may expand or contract more quickly than the interior, and due to the differential thermal expansion, stresses will develop • more severe on reheating or glazing a crown than cooling it. --------- Mechanism of Slow (subcritical) Crack Growth: • In glass, other silicates and other oxide ceramics, water molecules break the strained bonds at the crack tip. • In other ceramics, any aggressive liquid or gas can have similar effect (esp. at high T) - Active at mouth temperature. [progresses steadily over time, acceleratng at higher stress levels and ultimately leading to failure]
[Principles Of Tooth Preparation (25)*most*] 1) Factors Affecting Resistance - 3 of them 2) Axial walls ____ mm taper at ___ deg.
Factorsaffectingresistance 1. Magnitude and direction of dislodging forces (Resistance form may be more crucial). 2. Geometry (taper, diameter, height) of the tooth prep: - Axial walls 3mm taper at <10deg. - height: weight = 4:10 or greater. - USE Proximal groove or box: healthy tooth structure; perpendicular to the applied force (MD on single prep; BL on FPD prep); 2.5x diameter of the bur. 3. Physical properties of the luting agent - comprehensive strength; modulus of elasticity. - Adhesive resin >glass ionomer > ZPC > polycarboxylate > ZOE
______________ (i.e. transverse strength , *modulus of rupture*) is essentially a strength test of a bar supported at each end or a thin disk supported along a lower support circle under a static load. [Color : Ceramics & Porcelain (7?)] [know • main parameters to identify "strength"]
Flexural Strength (MPa = maximum flexural stretch measurement):
____________ or the critical *stress intensity* is... • a measure of the energy required to propagate critical flaws in the structure • a mechanical property that describes the resistance of brittle materials to the catastrophic propagation of flaws under an applied stress. Strength is ____ proportional to the square root of the flaw depth within the surface. [Color : Ceramics & Porcelain (7?)] [know • main parameters to identify "strength"]
Fracture Toughness. Red box: Strength is inversely proportional to the square root of the flaw depth within the surface.
When preparing the buccal and lingual axial reduction for Full Cast Metal Crown, where should the functional bevel be and what degree? [Tooth Preparation (measurements) (5)]
Functional bevel on functional cusp - 45 deg. to long axis
What investment materials are commonly used in metal alloys? [Wax Investment (3)] [must know what is used for metal alloy]
GYPSUM-BONDED INVESTMENTS: Mold materials most commonly used in the casting of dental gold alloys with liquids temperatures no higher than 1080oC. Normally used for gold inlays, crowns, and fixed and removable partial dentures. Not suitable for high-melting alloys. COMPOSITION: All gypsum-bonded investment powder consist basically of a refractory filler and a binder, with small amounts (less than 5%) of important modifying agents. Refractory is either cristobalite or quartz (or a mixture of the two) usually present in the 55% to 75% range. Binder is calcium sulphate hemihydrate (either plaster or stone) . Modifying agents are added to control properties. Effects of Composition on Setting and Thermal Behavior: (1) Refractory Cast gypsum can resist temperatures as high as 1000oC.. Addition of silica reduces heat resistance, but helps to control dimensional changes. (2) Binder: When heated, the cast gypsum binder shows marked contraction. Total linear contraction of cast gypsum prepared from plaster and heated to 700oC can be as high as 3%. Shrinkage for cast gypsum prepared from a high- strength stone is about 1%.
Glass Ionomer can be used to restore _________ or ________. _______ preparation and glass ionomer can be used to restore an ________ lesion on the _______ surface of a ________ tooth. [Must know restoration types and how to be done] [Diagnosis And Txt Plan (9)]
Glass Ionomer can be used to restore gingival abrasion or erosion. Tunnel preparation and glass ionomer can be used to restore an incipient lesion on the proximal surface of a posterior tooth.
What material is described? • Differ from feldspathic porcelains • SPECIAL SUBSET OF PARTICLE FILLED GLASSES • They contain more than 50 vol.% of fine and uniformly distributed crystals grown directly from the glass through a controlled crystallization process • The material is formed into the desired shape as a glass and then subjected to a heat treatment to induce partial devitrification (loss of glassy structure by crystallization of the glass) • This controlled nucleation and crystallization process involves a 2-stage heat treatment called 'cramming' [Color : Ceramics & Porcelain (7?)] [know crystal vs. glass]
Glass-Ceramics
_______ is the ability of a surface to reflect light into the SPECULAR direction. [Color Science (2)]
Gloss
Happiness = [Intro-2] Difficulty = [Dx and Tx planning (9)]
Happiness = reality-expectation :) Difficulty = Pt's Behavior + Technical Procedures
Metal Casting: What is the difference between high noble metal and noble metal? [Diagnosis And Txt Plan (9)]
High Noble = high Au content w. noble metal. Noble = Low Au content, has noble metal in it.
POLYSULFIDE RUBBER (MERCAPTAN) [Impression Materials (1)]
Highly accurate and relatively low cost impression material. Usually indicated for completely or partially edentulous impressions. Supplied as base and catalyst pastes. Available in low, medium, and high viscosities. Composition: - The base paste contains polysulfide polymer, reinforcing fillers, and plasticizers. - The accelerator paste contains lead dioxide (30%), hydrated copper oxide or organic peroxide as a catalyst, 1% to 4% sulfur as a promoter, and dibutyl phthalate or other nonreactive oils (17%) to form a paste. *Impression should be poured within 1 hour to minimize distortion*
ADDITION (VINYL) SILICONES [Impression Materials (1)]
Highly accurate impression material, suitable for all dental impression applications. Available as light, medium, heavy, and putty viscosities . Hydrophilic. Expensive. Composition: -- Silicone prepolymers with vinyl and hydrogen side groups. - One paste contains the vinyl-poly (dimethylsiloxane) prepolymer. - Second paste contains a platinum catalyst (chloroplatinic acid). Manipulation: - Same as condensation silicones. - If no hydrogen scavenger is present on the formulation, wait 1 hour before pouring impression. - Dimensionally stable for up to 1 week
IMPRESSION WAXES [Wax Patterns [contours & contacts] (4) ]
Impression waxes exhibit high flow and distort on withdrawal from undercuts. Corrective waxes are used as wash waxes to record detail and displace selected regions of soft tissue in edentulous impressions. Bite waxes are used for bite registration.
9.18 Quiz - Must know: What will happen to compressive strength of the stone model after you increase W/P?
Increasing Water to alter W/P => DECREASE compressive strength. (Higher W/P ratio: 1. decrease in strength & tear strength 2. runny consistency 3. increase in working time, setting time, increased flexibility)
___________ are materials consisting principally of an allotrope of silica and a bonding agent (gypsum or phosphates and silica). What are required properties of these materials?* (know)
Investment Materials [Wax Investment (3) - need to know the properties] - required properties: Easily manipulated, Sufficient strength at room temperature, Stability at higher temperature , Sufficient expansion, Beneficial casting temperatures, Porosity, Smooth surface, Ease of divestment, & Inexpensive.
Why does a red object look red? [Color Science (2)]
It reflects red wavelengths more than green and blue. The color that we see is what's left of the spectrum after part of it is absorbed by the object. e.g. Light strikes object => reaction depends => transparent, translucent, rough, glossy.
1941: • a paper published in the Journal of the American Ceramics Society (JACS) demonstrated an 'oddity in the thermal expansion' of a certain feldspar rock (with a potassium content over 11%) when melted and cooled quickly, forming a glass • when reheated, this glass had an extremely high thermal expansion • due to the formation of a new crystalline component not in the original rock, called _________. [Color : Ceramics & Porcelain (7?)]
LEUCITE (red). [know main crystals found in porcelain (leucite, lithium dislocate, zr]
[Gypsum & Alginate-5] What will happen to compressive strength of the stone model after you decrease W/P?
Lower W/P ratio: 1. increase in compressive strength & tear strength. 2."better" consistency 3. decrease in working time, setting time, flexibility.
[Gypsum & Alginate-5] What will happen to working time of impression material after you decrease W/P?
Lower W/P ratio: 1. increase in compressive strength & tear strength. 2."better" consistency 3. decrease in working time, setting time, flexibility.
Restorative Contours - Marginal Ridges. [Wax Patterns [contours & contacts] (4)]
MARGINAL RIDGES: 1. Discrepancy with the adjacent tooth in Height => food Impaction. 2. No Triangular Fossa => food impaction. 3. No occlusal embrasure => like a pair of tweezers. 4. No buccal lingual inclines => premature occlusal contacts. (must know what causes food impaction ) from google docs about what causes food impaction: "Occlusal gingival or faciolingual dimension of proximal contacts being too broad or too narrow. Also, Descrepency in height of marginal ridges or if there is no triangular fossa"
Classification according to fabrication technique (processing method) [know main restoration fabrication processes: 1. PFM (bonding mechanisms). 2. All ceramic (press, cad cam)] - with which is Sintering more popoular? with which is heat pressing more popular? [Color : Ceramics & Porcelain (7?)]
Metal Ceramics: - Sintering is more popular. - Heat pressing on metal. All Ceramics: (*THINK* C like S) - Sintering - Heat Pressing more popular. - Slip casting & Glass Infiltration. - Soft Machining + (glass infiltration, sintering or heat pressing). - Hard Matching is more popular. - Hard matching + heat treatment is more popular.
[Principles Of Tooth Preparation (25)*most*] At the similar taper, which will be more retentive: molar or premolar?
Molar because it has more surface area and the more SA => the more reTenTive.
SHORT AND LONG TERM SOFT DENTURE LINERS [Acrylic Resins & Temporization (4) ]
Most commonly used liners are plasticized acrylic resins. Can be heat or chemically activated. Chemically activated liners are considered short-term materials . Heat activated liners are considered long-term materials. Denture liners are subjected to degradation over time, and can present challenges in maintenance.
[Diagnosis And Txt Plan (9)] This serves as a complement tool in additional to clinical examination. It provides a LEGAL proof of patients current occlusion.
Mounted Diagnostic Casts on an articulator: • Allow clinician to modify occlusal pre-treatment plan prior to establish a definitive Tx Plan • Allow clinician to evaluate pt's occlusion in centric and eccentric positions • Allow clinician to determine inter arch distance, relationship between the teeth and alveolar ridge and allow clinician to make as many alteration to as clinician's desire w/ absence of the patient.
You want to do a fixed partial denture on three teeth: 1pm, 2pm, and 1m. Abutments are present on canine and second molar. Is doing the FPD a good choice? [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
No. The combined root surface area of teeth being replaced (pontic) is greater than the adjacent abutment teeth's (canine and 2M) combined surface area [think about sizes of teeth] => FPD would be a poor choice. - Evaluate Periodontal Ligament Area: want combined root surface area of the adjacent 2 abutment teeth to GREATER OR EQUAL than that of tooth being replaced (pontic) [pontic SA *<* abutment teeth surrounding]
GENERAL REQUIREMENTS OF A DENTAL ALLOY [Metal Alloys And Casting (6)]
Not produce harmful toxicologic or allergic effects. Chemical properties should provide resistance to corrosion and physical changes when in the oral cavity. Physical and mechanical properties (thermal conductivity, melting temperature, coefficient of thermal expansion, and strength) should meet certain minimum values* (see attached pic). The technical expertise needed for fabrication and use should be feasible for the average dentist and skilled technician. The metals, alloys, and companion materials should be plentiful, relatively inexpensive, and readily available.
What are the three major CONSIDERATIONS you need to keep in mind while designing a pontic? [Metal Framework Design (7)] [know pontics]
OCCLUSAL AND PROXIMAL CONTACTS SHOULD BE AT LEAST *1MM AWAY FROM THE JXN* OF PORCELAIN TO METAL (from google doc). • Biologic consideration [*occlusal function or chewing] 1. Patient comfort (cheek, tongue) 2. Cleansibility (glazed porcelain, smooth and conveX, open embrasure space). 3. Tissue contact - minimum contact on facial slope of ridge: T-shaped. - no pressure. 4. 4. Occlusal forces - reduction of the BL width of the pontic occlusal (1 tooth - 85%; 2 teeth - 75%; 3 teeth - 65%) => BUT, does not lessen harmful forces, rather preclude the development of harmonious and stable occlusion. • Mechanical consideration [*Prevent tilting of the abutment or adjacent and opposing teeth*] 1. Rigid to resist deformation 2. Strong connector to prevent fracture 3. Metal ceramic framework design to resist porcelain fracture. • *Esthetic* consideration 1. Gingival interface: - replicate form, contour, incisal edge, gingival and incisal embrasure, and color of the adjacent teeth - tissue-pontic junction of the labial contour: When poorly adapted => shadow & food collection. 2. Incisogingival length a. recontour from gingival 1⁄3 - 1⁄2 b. simulate the normal crown and root with emphasis on the CEJ c. pink porcelain to simulate the gingival tissue 3. Mesiodistal width - visual perception principles - width identified by the relative positions of the mesiofacial and distofacial line angles - alteration of the proximal areas; proportion the retainer and pontic.
[Occlusion And Articulator (10)] [ must know Occlusal Morphology] Anterior Guidance: Vertical overlap of upper and lower teeth is called?
Overbite- greater overbite, cusps should be greater. ("Shorter cusps = more horizontal overlap = Overjet Longer cusps = more vertical overlap = overbite")
[Occlusion And Articulator (10)] Anterior Guidance: Horizontal overlap of the upper and lower teeth is called? [ must know Occlusal Morphology]
Overjet - the greater the overjet, the shorter the cusps should be. ("Shorter cusps = more horizontal overlap = Overjet Longer cusps = more vertical overlap = overbite")
from google docs - wax patterns: a. This is about dental anatomy eg: proximal contacts and contours - where are the proximal contacts and how should the axial surface be contoured?
PROXIMAL CONTACTS CONVEX (anteriors incisal 1/3, moving lower as go distally towards canine; posteriors occlusal 1/3 except for distal of max 1m which is middle 1/3 - slightly facial to the middle of the tooth except for max 1st distal which is slightly lingual). AXIAL HEIGHT OF CONTOUR FOR FACIAL (Gingival 1/3) & LINGUAL (Middle 1/3) = CONCAVE OR FLAT, NEVER CONVEX ( emergence profiles should be concave or flat, never convex). Undercontouring => gingival recession (nothing major). Overcontouring => inflammatory change in 4 weeks --- Food deflection theory for axial contours is apparently no longer supported".
Diagnosis for Missing Tooth/Teeth [Diagnosis And Txt Plan (9)]
Partially Edentulous Area a) Kennedy Classification I, II, III, IV with or without modification b) PDI (Prosthodontic Diagnostic Index Classification 1,2,3,4)
Porcelain-fused-to metal crown- 1962 Weinstein, Katz: Patent 1 - identified the formulations of feldspathic porcelain that enabled the systematic control of the sintering _________ and ______. Patent 2 - described the components that could be used to produce ____ that bond chemically to and that are __________ compatible with the feldspathic porcelains. [Color : Ceramics & Porcelain (7?)] [know feldspathic porcelain manufacture]
Patent 1 • identified the formulations of feldspathic porcelain that enabled the systematic control of the sintering temperature and coefficient of thermal expansion. Patent 2 • described the components that could be used to produce alloys that bond chemically to and that are thermally compatible with the feldspathic porcelains
[Principles Of Tooth Preparation (25)*most*] __________ is the :imaginary line along which the restoration is placed onto or removed from the prep. How do you check out taper / undercut? [must know how to check undercut]
Path of Insertion: To check out taper/ undercut: - 30cm (12") with one eye - 1⁄2" at an angle with one eye 3 Methods to Check for undercut: 1. probe parallel cervical 3rd of tooth: undercut will see small gap at bottom near that part of wall u cut back. 2. Keep burr parallel to the surface on the margin: undercut u will see gap. 3. Look from occlusal view of prep - u won't be able to see the full circumference /width of the margin w. an undercut. [notes from google doc: "---- Check for occlusal clearance ---- Check M/D taper from buccal and lingual aspect ---- Check BL taper and path of insertion (undercuts) from mesial aspect ---- Check concentricity from occlusal aspect" . View occlusal of tooth at 30cm/12" vertically with one eye opened to determine undercuts. Can be missed if two eyes are opened --- should always be able to see margin]
PATTERN WAXES [Wax Patterns [contours & contacts] (4) ]
Pattern Waxes = Inlay, resin, casting, and base plate waxes. - Type I inlay waxes are soft and used for indirect inlay technique and attachment of miscellaneous parts. - Type II inlay waxes are hard waxes used for preparing direct patterns in the mouth Casting waxes are used for thin sections of certain removable and fixed partial denture patterns. Base plate wax is used in the construction of full denture patterns and occlusal rims. - Type I base plate wax is soft, and used for veneers and contours - Type II is a medium- hardness wax. - Type III is the hardest base plate wax
First acrylic resin introduced in 1936? a. bis-GMA b. PMMA c. UDMA d. Epoxy-Resin based [Acrylic Resins & Temporization (4) ]
Polymethylmethacrylate (PMMA) was introduced in 1936. In the mid 1940s, room- temperature polymerizing materials became available. Newer materials can be bis-GMA (bisphenol-A glycidymethacrylate), UDMA (urethane dimethacrylate), or epoxy resin based
Know feldspathic porcelain manufacture [Color : Ceramics & Porcelain (7?)]
Porcelain Jacket Crown (1903) by C.H. Land - made from feldspathic porcelain clay - fabricated by burnishing a piece of thin platinum foil over a die, and brushing layers of dry clay over refractory skeleton - was composed of about equal parts of kaolin, and fine grains of pure silica (in the form of crystalline quartz) - not very esthetic, too opaque. --------- - ceramic technologists began to formulate feldspathic porcelains with less and less kaolin until by 1938 kaolin was omitted as the proportion of aluminous kaolin decreased, the strength of the glass declined. ------------ Dental feldspathic porcelain structure: • "glass formers"- all are metallic oxides • SILICA IS MOST IMPORTANT (RED): *exist in 4 different forms*: CRYSTALLINE QUARTZ, crystalline cristobalite, crystalline tridymite and noncrystalline fused silica. - when the QUARTZ CRYSTAL is heated to its melting temperature, the silicon and oxygen atoms remain covalently bonded, but they begin to trade partners freely disrupting the orderly lattice. as the temperature rises above the melting point, more and more of the lattice disappears and the melt becomes thinner and thinner--i.e. less and less viscous.
[Intro-2] Fixed Prosth Pre-treatment, during treatment, and post-treatment (must know flow of procedure steps - see bold / attached image)
Pre-Treatment: 1) Examination - comprehensive evaluation - dx and treatment plan. 2)*During Treatment: 1. Tooth preparation 2. Use CAD/CAM for: - provisional crown fabrication - final impression and/or bite registration - form working & opposing cats - die trimming, mount casts, & lab rx. 3. Try-In, Insert Final Restoration and Excess Cement Removal 4. Homecare & Regular Recare* 3) Post Treatment: 1. Complications (on other fc's)
Cantilever fixed partial denture replacing a mandibular first molar, using both premolars as abutment teeth. To minimize stress on the abutments, make the pontic size of? [Diagnosis And Txt Plan (9)]
Premolar - instead of doing a molar, u do a premolar bc its smaller size.
When should shade comparisons be made? [Color Science (2)] [know]
Principles of Shade Selection 1. Teeth to be matched must be clean 2. Remove bright colors from field of view - makeup / lipstick/ tinted eye glasses - bright gloves - neutral operatory walls 3. View patient at eye level 4. Evaluate shade under multiple light sources 5. MAKE SHADE COMPARISONS AT BEGINNING OF APPOINTMENT (red). 6. Shade comparisons should be made quickly to avoid eye fatigue 7. Ideal distance 25-35 cm 8. A single matching trial should not take more than 5 seconds 9. Take breaks looking at a neutral gray card 10. Wet the tooth and the tab to neuralize texture differences 11. Reduce the number of potentially adequate tabs as quickly as possible. **- Do not forget translucency, gloss, surface roughness, local characteristics - Check under different lights**
[Principles Of Tooth Preparation (25)*most*] Purposes of tooth preparation?
Purposes: 1. Space for restorative material 2. Removal of unsound tooth structure including dental caries 3. Removal of undercut or height of contour
St 1. IMPRESSION PLASTER is rarely used. St 2. Main component of impression plaster is epoxy resin. [Impression Materials (1)]
Rarely used. Main component is calcium sulfate hemihydrate . Impression plaster is rigid and will break rather than bend. Must be stored in an airtight container
[Principles Of Tooth Preparation (25)*most*] ____________ is any areas of prep under compression.
Resistance Area
__________ is the feature of a tooth preparation that resists dislodgment of a crown in a VERTICAL direction or ALONG the path of placement (GPT-9). [Diagnosis And Txt Plan (9)]
Retention Form when uhave intimate contact like cups stacked on top of each other and u try to take top cup off.
Rods vs. Cones - which ones have more prolonged responses? [Color Science (2)]
Rods are monochromatic so see black/white. ROD RESPONSES ARE MORE PROLONGED (red) than those of cones. Cones are able to see blue, green, & red (sensitive).
Root Caries can be restored with ____________. Rampant Caries can be brought under control with _________________. [Must know restoration types and how to be done] [Diagnosis And Txt Plan (9)]
Root caries restored w. glass ionomer. Rampant caries can only be brought under control w. glass ionomer.
TUFF-TEMP PLUS [Acrylic Resins & Temporization (4) ]
Rubberized- urethane chemistry. Not affected by heat and grinding. High flexural strength without brittleness. Dual-cure material (chemical and light). Available in automix cartridge and syringe, provisional add-on, and provisional glaze.
Enamel acts as a filter and has the ability to selectively forward the _____ waves, and reflect the ______ waves [Color Science (2)] [know bc red]
SELECTIVELY FORWARD THE LONG WAVES, AND REFLECT THE SHORT WAVES. • because of this reflection, incisal enamel can be viewed as having a bluish-white color • when long waves (that were being transmitted relate to dentin) are reflected back, they give enamel an orange glaze (an effect known counter- opalescence).
[Principles Of Tooth Preparation (25)*most*] The path of insertion of a preparation for a metal-ceramic crown should be __________ to the long axis of the tooth. If path is directed facially, what happens? What if its directed lingually?
Should be parallel. The path of insertion of a preparation must parallel the adjacent proximal contacts or it will be prevented from seating. If directed facially, the prominent facioincisal angle may create esthetic problems of over contouring or opaque show-through. If path is directed lingually, the facial surface will intersect the lingual surface, created a shorter preparation; It may also encroach on the pulp.
[Diagnosis And Txt Plan (9)] Imp. Things to look at for prosth case in Exam / Analysis
Smile Line, Occlusal Analysis, Tissue Biotype: Thin Scalloped Gingiva or Thick Flat Gingiva.
SPRUING - KNOW [Metal Alloys And Casting (6)]
Sprue is the "channel or hole through which plastic or metal is poured or cast into a gate or reservoir and them into a mold". It forms a mount for the wax pattern and fix the pattern in space so a mold can be made. It creates a channel for elimination of wax during burnout. This channel allows for molten metal to enter such mold. Sprue button is "the excess material remaining at the base of the mold after dental casting". The sprue must be large enough so it remains open until the casting solidifies and short enough to allow rapid filling of the mold. It should ALWAYS ATTACH to the BULKIEST part of the pattern. *Wax sprues are the most common*
Special Considerations for FPD: St 1. Tooth position and alignment are maintained in part by the interaction between teeth. St2. A fixed partial denture may be *fabricated* without first re-establishing the occlusal plane. [Diagnosis And Txt Plan (9)]
St 1 is True. St 2 is so false - you need to make sure occlusion is restored by correction of occlusal plane in conjunction with placement of FPD. Since when a tooth is removed/lost, adjacent teeth often migrate into the vacated spot. So if you fabricate the FPD without first re-establishing the occlusal plane, an occlusal interference may be created.
[Principles Of Tooth Preparation (25)*most*] "Preservation of Tooth Structure": St 1. You want to have maximum taper. St 2. Shoulder margin requires more reduction than chamfer. St 3. Antimicrobial Agents (consepsis) after prep and before cementation may cause injury.
St 1 is false (minimum taper!); St 2 is true!; St 3 is true! 3. Cause of Injury: • Temperature: water spray + high speed • Chemical: - Dentin bonding agent - No chemical solvents and surfactants . • Bacterial: antimicrobialagents (Consepsis) - After prep and before cementation - unknown benefit o Remove all carious dentin 4. Guidelines: 1) Partial coverage vs. Full coverage 2) Minimum taper 3) Occlusal surface: anatomic planes or inclines - want to KEEP buccal and lingual inclines when preparing a tooth for crown. (keeps resistance form) 4) Maximal thickness of dentin 5) Selection of margin geometry: shoulder vs. chamfer => shoulder requires more reduction (it has like square bottom but chamfer is rounded off) ----- attached pic: enamel and dentin thickness(mm) WITH 1.5MM REMOVED (RED ----
St 1. Restorations too LOW in value are easily Detected. St 2. Objects of DIFFERENT hues/chroma can have the SAME value. St 3. Values of natural teeth range from 5.5 to 8.5
St 1 is false - Restorations too high in value (like super white crappy looking ones) are easily detected. St 2 is true! St 3 is true: 5.5-8.5 value (0 = black, 10 = white).
ETHYL SILICATE-BONDED INVESTMENTS [Wax Investment (3)]
Supplied as powder and liquid. Powder consists of refractory particles of silicas and glasses, along with calcined magnesium oxide and other refractory oxides. Liquid is a stabilized alcohol solution of silica gel, or on two liquids systems, ethyl silicate and an acidified solution of denatured ethyl alcohol. Advantages: - Ability to cast high-temperature cobalt- chromium and nickel-chromium alloys - Good surface finish - Low distortion - High thermal expansion - Less dense when compared to phosphate bonded investments - Easier to separate casting from investment Disadvantages: - Added steps during the processing - Extra care needed during handling. - Lower strength and higher thermal expansion requires expert casting to avoid problems.
[Principles Of Tooth Preparation (25)*most*] ______ is defined as the convergence of two opposing external walls of a crown prep as viewed in a given plane, e.g. MD or BL
Taper
Colors of teeth [Color Science (2)]
Teeth are predominantly light, whitish-yellowish and slightly reddish
__________ is to "establish esthetics, occlusal stability, and function for a limited time in preparation for the definitive prosthesis; to verify therapeutic outcome and patient acceptance before the definitive prostheses".
Temporization [Acrylic Resins & Temporization (4) ]
Intrinsic color of tooth is associated with? Extrinsic color of tooth is associated with? [Color Science (2)]
The color of tooth is determined by combination of two colorimetric effects: 1. intrinsic = reflection and absorption of light, and 2. extrinsic = coloring materials interacting w. enamel - coffee, tea, tobacco).
CASTING [Metal Alloys And Casting (6)]
The lost wax technique is one of the oldest methods available. Inexpensive and convenient to use even on complicated shapes. Desired accuracy is about 0.1%. *Shrinkage (wax + alloy) = investment expansion*
What would be a superior abutment - the molar with fused roots, or the molar with divergent roots? [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
The molar with divergent roots (a) will be a better abutment tooth than one whose roots are fused (b).
[Diagnosis And Txt Plan (9)] MUST KNOW: The optimum crown-root ratio for a fixed partial denture abutment is ________. A ratio of ______ is the maximum that is acceptable. [must know how to analyze an abutment!]
The optimum Crown-Root ratio for a fixed partial denture abutment is 2:3. A ratio of 1:1 is the maximum that is acceptable.
PROPERTIES of investment materials [Wax Investment (3) - need to know the properties]
The particle size affects the smoothness of the mold cavity surface. Excessive roughness will interfere with the fit. The total expansion of currently available inlay investments are in the range of 1.5% to 2.5%. Modern methods of casting small restorations can be classified into (1) hygroscopic expansion techniques and (2) thermal expansion techniques. Inlay investments have wet compressive strengths mostly in the range of 2 to 6 MPa. Denture investments have wet compressive strengths in the range of 9 to 14 MPa
The standard illuminant for dentistry, D55, is defined as in Washington, DC, June, noon to 1 PM, with a slight overcast, a color temperature of _______, and a color- rendering index (CRI) ______. [Color Science (2)] [this was red]
The standard illuminant for dentistry, D55, is defined as in Washington, DC, June, noon to 1 PM, with a slight overcast, a color temperature of 5,500 K, and a color- rendering index (CRI) 90
[Principles Of Tooth Preparation (25)*most*] ______ is the mechanical treatment of dental disease or injury to hard tissues that restores a tooth to original form.
Tooth Preparation
[Gypsum & Alginate-5] Chemistry: Traditional hemihydrate plaster is produced by ______ calcination. Medium- and high- strength plasters (stones) manufactured by ______ calcination have a stronger set mass.
Traditional hemihydrate plaster is produced by dry calcination. Medium- and high- strength plasters (stones) manufactured by wet calcination have a stronger set mass.
What is the difference between Translucent and Transparent? [Color Science (2)]
Transparent: all light went thru. Translucent: some light reflected, some went thru.
The sequence of procedures planned for the treatment of a patient after diagnosis
Treatment Plan [Diagnosis And Txt Plan (9)]
IMPRESSION COMPOUND Which is FALSE? a. Type 1 is for full-crown impessions, partiall or completely edentulous jaws. b. Type II for making impression trays. c. Thermoplastic property allows it to be used warm (45oC) and cooled to oral temperature (37oC). d. Very useful for recording of undercuts. [Impression Materials (1)]
Type I for full-crown impressions, partially or completely edentulous jaws. Type II for making impression trays. Cannot be used for the recording of undercuts. Thermoplastic property allows it to be used warm (45oC) and cooled to oral temperature (37oC).
[Final Impression / Tissue management by Dr. Lamberti (2) ] Materials: Addition silicone(Poly-Vinyl-siloxane)
Used for most impressions. Advantages: - Great dimensional stability (can be poured more than once ,even the next day) - Accuracy - Very short setting time - Automix available. Precautions: - Care to avoid bubbles when pouring (Poor wetting) - Setting inhibition for some putties by latex gloves
CONDENSATION SILICONE RUBBER [Impression Materials (1)]
Used mainly for fixed partial dentures and single-unit partial coverage restorations. Supplied as either two-paste or paste-liquid systems. Available in low, medium, high, and very high (putty) viscosities. Composition: - Base paste usually contains a moderately high-molecular-weight poly(dimethylsiloxane), and orthoalkylsilicate for cross-linking and inorganic filler (30% to 40% filler, with putty containing as much as 75%). - The catalyst paste (or liquid) will contain a metal organic ester and an oily diluent, plus a thickening agent. The metal organic ester catalyzes the reaction.
[Final Impression / Tissue management by Dr. Lamberti (2) ] Materials: Condensation silicone
Used mostly for lab procedures Advantages: - Relative short setting time Disadvantages: - Poor wetting Byproducts of polymerization reaction are alcohol and water. As a result, evaporation from the set material causes dimensional instability Precautions: - Caution to avoid bubbles when pouring
What are DENTAL WAXES? [Wax Patterns [contours & contacts] (4) ]
Wax is one of several esters of fatty acids with higher alcohols (usually monohydric alcohols). Dental waxes are combinations of various types of waxes compounded to provide the desired physical properties. Uses include patterns for inlays, crowns, pontics, partial and complete dentures, and for bite registrations.
Special Considerations for FPD: A mandibular molar tilts mesially before seating the FPD. What is going to intrude on the path of insertion for the FPD to be properly seated? a. the tooth mesial to the FPD intruding on the path of insertion will prevent the FPD to seat. b. the toot distal to the FPD intruding on the path of insertion will prevent the FPD to seat. (a) If tooth is not an implant, what should you use to fix the tilted molar? a. extraction b. RPD c. orthodontics (b) If tooth is an implant and so there's a tilted molar abutment, what can you use to help seat the FPD? [Diagnosis And Txt Plan (9)]
When a mandibular molar tilts mesially, there is a discrepancy between its long axis and that of the premolar. This fixed partial denture will not seat because the tooth distal to the fixed partial denture intrudes on the path of insertion. (A) You wanna use Orthodontic appliance (e.g. braces) for uprighting a tilted molar. (B) - Fixed partial denture using a proximal half crown as a retainer on a tilted molar abutment. - Fixed partial denture using a telescope crown and coping as a retainer on a tilted molar abutment. - A nonrigid connector on the distal aspect of the premolar retainer compensates for the inclination of the tilted molar.
[Gypsum & Alginate-5] Fill in the blanks about the The Setting Process: WHAT R THE 4 STAGES OF SETTING?
When hemihydrate (traditional plaster) is mixed w. water in the correct proportions, a thick slurry is formed. Mix is a two-phase suspension of hemihydrate particles in a saturated aqueous solution. The setting reaction is the reverse of the first stage of dehydration and is EXOthermic. (2CaSO4 • 1/2H20 + 3H20 → 2CaSO4 • 2H20) . The DIFFERENT WATER REQUIREMENTS of plaster, stone, and high- strength stone are mainly the result of differences in the apparent DENSITY of the powder. The setting process is continuous from the beginning of mixing until the setting reaction is complete. The four stages of setting can be designated as (1) FLUID, (2) PLASTIC, (3) FRIABLE, and (4) CARVABLE The setting reaction causes a decrease in the true volume of the reactants. Once the mix begins to solidify, an isotropic expansion is observed.
9.18 Quiz What is your articulator's brand name? What type of articulator? Is it an Arcon or Non-Arcon articulator?
Whip Mix = Semi-Adjustable Arcon.
Do Digital tooth shade matching products exist on the market? [Color Science (2)]
Yea e.g. VITA easy shade compact.
Clinically to Maximize Durability: - Avoid _______. - Provide maximum _____ thickness for the ceramic. - Use the Highest _______ substrate possible. - Bond the ______. [Color : Ceramics & Porcelain (7?)] [know how to maximize durability: for PFM, and for all ceramic restorations]
[! bc red] • avoid stress raisers! • provide maximum occlusal thickness for the ceramic! (strength increases with the square of the thickness) • use the highest elastic modulus (stiffness) substrate possible!; i.e. metal or ceramic versus resin-based composite) • bond the restoration!, ceramic-cement and cement- tooth (or substructure) • develop broad, not pinpoint, occlusal contacts
[Occlusion And Articulator (10)] Manually Protected Occlusion / Canine Guidance [MUST KNOW canine guidance]
[THINK: NO ANTERIOR CONTACTS IN MIP] 1. Centric Position: - occlusal contact condition: point centric; only posterior teeth make contact; anterior teeth have a space of 30 microns. - interarch relation: one-tooth to one-tooth; cusp-to-fossa relation; tripodism. 2. Protrusive Position: maxillary incisors guide the mandible; canine and posterior teeth diclude; mesial inclines of mandibular first premolar buccal cusps may contact. 3. Lateral Position: - working: maxillary canines guide the mandible; it is permissible to have other anterior teeth contact; posterior teeth disclude. - nonworking: no tooth contacts. ---------- NOTES: Protected Occlusion - Canine guidance is typical of this. - In centric, only posterior teeth r in contact. (anterior teeth barely in contact or 30 micron space between upper/lower anterior teeth). - In protrusion, maxillary incisors in contact and sometimes anterior teeth included in this scheme. - Working side, only canine is in contact ideally (but anterior teeth can be included also, but not non-working contacts). - Exam: memorize the schemes on all these slides. *Canine Guidance: occurs on the canines during a lateral excursion of the mandible, results in the disocclusion of non working teeth. -- class three lever*
[Occlusion And Articulator (10)] Group Function / Unilateral Balanced Occlusion [google doc said know this]
[THINK: NO NONWORKING TOOTH CONTACTS AND ONLY MAX INCISORS CONTACT DURING PROTRUSIVE] 1. Centric Position: - occlusal contact position: long centric; anterior teeth may or may not contact. - interarch relation: one-tooth to two-teeth; cusp-to-ridge relation. 2. Protrusive Position: maxillary incisors guide the mandible; canines and posterior teeth disclude. 3. Lateral Position: - Working: maxillary lingual inclines of anterior and posterior buccal cusps guide the mandible. - Nonworking: no tooth contacts.
[Occlusion And Articulator (10)] Balanced Occlusion (Bilateral Balanced Occlusion) [google doc said know this]
[THINK: NORMAL / ALL TEETH TOUCH IN PROTRUSIVE MOVEMENT] 1. Centric Position: - occlusal contact position: point centric; anterior and posterior teeth contact. - inter arch relation: one-tooth to two-teeth; cusp-to-ridge relation. 2. Protrusive Position: all max. an mand. teeth contact. 3. Lateral Position: - Working: lingual inclines of anterior teeth, and buccal and lingual cusps of posterior tech make contact. Cross-tooth balance. - Nonworking: lingual cusps of max. teeth and buccal cusps of mind. teeth make contact. cross-arch balance.
Highly esthetic dental ceramics are a. predominantly glassy materials b. Particle-filled glasses c. Polycrystalline ceramics. Higher Strength ceramics are a. predominantly glassy materials b. Particle-filled glasses c. Polycrystalline ceramics. [Color : Ceramics & Porcelain (7?)]
[based on "crystalline phase" • 3 main composition categories] 1. Predominantly glassy materials 2. Particle-filled glasses 3. Polycrystalline ceramics. *Highly esthetic dental ceramics are glassy**Higher strength ceramics are crystalline*
The Munsell Color System is a ________ that specifies colors based on three color dimensions: _____, _____, and ______. It was created by Professor ________ in the first decade of the 20th century, and adopted by the USDA as the official color system for soill research in the 1930's. [Color Science (2)]
a "COLOR SPACE" that specifies colors based on three color dimensions: HUE, VALUE AND CHROMA. created by Professor ALBERT H. MUNSELL in the first decade of the 20th century, and adopted by the USDA as the official color system for soill research in the 1930s. (caps bc red)
What is the ideal occlusal reduction for an all ceramic crown? a. 2 mm b. 1.5-2 mm c. 1-1.5 mm d. 1 mm e. 0.5 mm
a ( Occlusal reduction: - Gold crown (full metal): 1 - 1.5 mm (1.5mm for functional cusp; 1.0mm for nonfunctional cusp) - PFM and all ceramic crown: 2 mm of clearance. )
What is the ideal occlusal reduction for a PFM crown? a. 2 mm b. 1.5-2 mm c. 1-1.5 mm d. 1 mm e. 0.5 mm
a ( PFM HAS MORE OCCLUSAL REDUCTION THAN A REG. GOLD METAL CROWN!) (Occlusal reduction: - Gold crown (full metal): 1 - 1.5 mm (1.5mm for functional cusp; 1.0mm for nonfunctional cusp) - PFM and all ceramic crown: 2 mm of clearance. )
[Gypsum & Alginate-5] What will happen to consistency of impression/stone model after you increase W/P? a. runny b. better c. nothing
a is answer. (Higher W/P ratio: 1. decrease in strength & tear strength 2. runny consistency 3. increase in working time, setting time, increased flexibility)
3. What is the shape of the border movements in the horizontal plane? A. rhomboid (diamond) B. shield C. square D. oval E. triangle
a. (shield is front and theres no CRl; envelope is saggital)
[Principles Of Tooth Preparation (25)*most*] Advantages of bevel
a. Burnishability b. Less marginal discrepancy (slip joint) c. Aids in contouring the restoration e.g. when the margin is on the root [NOTE THO - not good for all ceramic crowns bc bevel is thin and does not allow for adequate thickness of material --> might crack]
For a Full Cast Metal Crown prep, how deep should your depth cuts or grooves be when doing the occlusal reduction? [Tooth Preparation (measurements) (5)]
about 0.8 - 1.2 mm, using #2 round bur or *coarse round end tapered diamond*
________ (1) pertains to polymers of acrylic acid, methacrylic acid, or acrylonitrile; (2) any of a group of thermoplastic resins made by polymerizing esters of acrylic or methyl-methacrylate acids
acrylic resins [Acrylic Resins & Temporization (4) ]
A simple _______ restoration can be placed in an MOD preparation on a molar.
amalgam restoration
15. Which of the following is true? A. Males have slightly more yellow teeth than females B. Max central incisors are higher in chroma than max lateral incisors C. Teeth become lighter with age D. Max anterior teeth are more yellow than mandibular anterior teeth E. All of the above are false
answer: D (males SAME as females; max CI's higher in VALUE than max LI's; teeth become DARKER w. AGE).
______ is the intensity or saturation of a hue. a. Hue b. Chroma c. Value d. Fluorescence e. Gloss
b
Cast restoration, e.g. metal crown or lingual margin of PFM crown - width of chamfer margin? a. 0.1mm-0.3mm b. 0.3mm-0.5mm c. 0.5mm-0.8mm
b (Cast restoration, e.g. metal crown or lingual margin of PFM crown: 0.3 - 0.5 mm in width) (i made this q)
For the clinician a simple but efficient way to approximately evaluate the fluorescence (of teeth or restorations) in vivo is to check the optical interaction with a modified light source such as ______. [Color Science (2)]
black light
Common combinations for fixed prosthodontics A. 7 single crowns + 3 Implant crowns B. 9 Single crowns + 1 unit FPD C. 8 single crowns + 2 unit FPD D. 9 single crowns + 2 unit FPD
c ( Common Combinations all sum to 10 (think** 9 is eaten (seven ate nine) so its the one w. implant crown): • 7 single crowns + 3 unit FPD (Teeth or Implant supported) • 9 single crowns + 1 Implant Crown or • 8 single crowns + 2 unit FPD (Teeth or Implant supported))
Which restoration will last longer? This is the restoration type has more RESISTANCE to removal forces. a. 3/4 Crown b. 7/8 Crown c. All-Metal Crown d. MOD Onlay [Diagnosis And Txt Plan (9)]
c (MOD Onlay < 3/4 Crown < 7/8 Crown << All-Metal Crown). [dont confuse - all metal crown isN't same as saying amalgam restoration]
1. Which of the following is not the advantages of supragingival margin? A. Easily finished without soft tissue trauma B. Kept plague free C. Esthetic restoration D. Restoration can be easily evaluated E. Impression easily made
c is answer. - Adv supraging. margins: 1) Easily finished w.o soft tissue trauma 2) Kept plaque free 3) Impression easily made 4) Restoration can be easily evaluated
2. What is the most common complication for a single crown? a. Loss of retention b. Porcelain veneer fracture c. Need to endodontic treatment d. Fracture e. Caries 3. Second most common complication is? [MUST know two!!]
c is answer. Common Complications for Single Crown = root canal (3%); porcelain veneer fracture (3%), loss of retention is 2%).
What is the correct order for Step-By-Step Procedure for Full Cast Metal Crown? a. Evaluation, Occlusal Reduction, Buccal and Lingual Axial Reduction, Proximal Axial Reduction, Finishing. b. Occlusal Reduction, Proximal Axial Reduction, Buccal and Lingual Axial Reduction, Finishing, Evaluation. c. Occlusal Reduction, Buccal and Lingual Axial Reduction, Proximal Axial Reduction, Finishing, Evaluation. d. Evaluation, Proximal Axial Reduction, Occlusal Reduction, Buccal and Lingual Axial Reduction, Finishing.
c. • Step-by-Step Procedure for Full Cast Metal Crown: 1. Occlusal reduction! 2. Buccal and lingual axial reduction 3. Proximal axial reduction 4. Finishing 5. Evaluation
All of the following are advantages of full cast metal crown, EXCEPT: a. strong cylindrical shape b. modification of form and occlusion c. removal of less tooth structure than partial coverage d. To allow improved access for teeth with furcation involvement (fluting or barreling).
c. Gotta remove more tooth structure. (Full Cast Metal Crown : [Tooth Preparation (measurements) (5)] • Advantages: 1. Strong: cylindrical shape 2. Greater retention and resistance than partial coverage 3. To modify the form and occlusion 4. Contact areas can be conveniently developed 5. To allow improved access for teeth with furcation involvement: fluting or barreling. • Disadvantages 1. Removal of larger amount of tooth structure than partial coverage 2. Adverse effects to pulp and periodontium 3. Display of metal 4. Vitality test not feasible)
Which of the following is an advantage of polyether (Imgpregum): A. High polymerization shrinkage b. Set material is stiff c. Relatively short setting time d. Absorption of water (should be stored dry). (i made this q)
c. It has LOW polymerization shrinkage (another advantage). Being stiff and absorption of water are both disadvantages. (Polyether (Imgpregum): Used for most impressions, except for very long and thin teeth Advantages: - Dimensional stability (can be poured more than once ,even the next day) - Accuracy - Low polymerization shrinkage - Relatively short setting time - Automix available(Pentamix machine) Disadvantages: - Set material very stiff - Absorption of water (should be stored dry) Precautions: - Care not to break the teeth when separating the cast - Block undercuts - Care for perio involved teeth)
Cantilever fixed partial denture replacing a maxillary lateral incisor, using the ______ as the abutment. [Diagnosis And Txt Plan (9)]
canine
Observer - Instrumental: Analyzers that are reflected through what are reliable enough? Those that are reflected though what have high precision? [Color Science (2)]
colorimeters: • analyze the values for red, green and blue reflected *through filters that simulate sensing photoreceptor cells of the human eye* • "RELIABLE ENOUGH" (red). spectrophotometers: • measure and record the amount of light reflected or transmitted from the object *through its wavelength* • HIGH PRECISION (red) , sensitivity to measure absolute colors and are equipped with spectral distributions of various illuminants • complex and expensive • hard to measure vital teeth
Indirect Inlays of ________ can be used for proximo-occlusal restorations on posterior teeth. [Must know restoration types and how to be done] [Diagnosis And Txt Plan (9)]
composite resin
Restorative Contours - proximal contacts should be ______. [Wax Patterns [contours & contacts] (4)]
convex! (or straight to convex, but NEVER concave). Also, proximal contact dimension: use 40-30-20-20 % rule for the anterior. *[dont confuse- proximal contacts r convex; axial emergence profile is concave - think: cave men near to wear axe. pro baseball tex ]*
Which of the following is the advantage of using a CHAMFER margin design? a. More retention b. Less resistance c. More durability d. Less stress
d (LESS STRESS)
Most common complication for Resin Bonded FPD is [know]
debonding,followed by tooth discoloration. (- Debonding 23% - Tooth Discoloration 18% - Caries 7%)
know from google doc - Tissue management and final impression: What is it impregenated (agent) with?
displacement cords are impregnated with an astringent (hemodent) with aluminum or iron salts that cause ischemia. Sometimes they are pre-impregnated with epinepherine
Factors affecting the RETENTION of a tooth preparation include all of the following EXCEPT: a. magnitude of the dislodging forces b. roughness of the fitting surface of the restoration c. Taper d. casting alloy material and core build up material e. none of the above
e (they all affect retention!) ( Factors affecting retention = 1. MAGNITUDE of the DISLODGING FORCES: - stickiness of food, surface area force is loaded, and surface texture of restoration. (resistance form may be more crucial here). 2. GEOMETRY OF the tooth PREP: - taper (6 - 10; 10 to 20 is acceptable; 2 to 3 deg for round end tapered) - escape of excess luting agent. - slight undercuts in cylindrical prep preventing the restoration from seating. - More Surface area => more retentive (molar > premolar at the same taper). - stress concentration in luting agent or cement: round occluso-axial line angle; cohesive failure. - type of preparation: partial vs. full coverage; groove or box; -> limit the paths of insertion. 3. ROUGHNESS OF the FITTING SURFACE of the restoration: - roughen or groove the internal surface of restoration by air abrading w. 50u alumina. 4. MATERIALS being cemented: - casting alloy: base metal > gold w. polycarboxylate. - core or buildup material: composite vs. amalgam. 5. Film thickness and PROPERTIES OF LUTING AGENT OR CEMENT: - Type: ZPC< glass ionomer< adhesive resin - Film thickness: uncertain)
Impressions can be useful for all of the following except: a. Evaluate the relative alignment between maxillary and mandibular arches. b. Evaluate occlusal relationship c. Fabrication of restoration and prostheses. d. Register and reproduce the form and relationship of teeth and oral tissues. e. None of the above
e - Casts of the mouth (the positive cast is made once u fill the impression aka negative reproduction of tissues w. dental stone) are used to evaluate the relative alignment between maxillary and mandibular arches, occlusal relationship, and fabrication of restoration and prostheses.
Which of the following is a technique for CR record? a. One hand chin point guidance b. Bimanual manipulation c. UNGUIDED techniques d. Tongue tip to soft palate e. all of the above are techniques for CR interocclusal record
e! ( [Occlusion And Articulator (10)] • Techniques for CR record: 1. One hand chin point guidance 2. Bimanual manipulation (Dawson's technique) 3. Unguided techniques 4. Tongue tip to soft palate )
Which is NOT included in the armamentarium for Full Cast Metal Crown: a. Basic Instruments B. High Speed handpiece C. Low speed handpiece d. Diamond burs (Tufts kid in preclon, Brassler) e. All of the above are included
e. • Armamentarium for Full Cast Metal Crown: 1. Basic instruments 2. High speed and low speed handpieces 3. Diamond burs: Tufts kit in preclin (Brassler®) [DONT WORRY TOO MUCH ABOTU THIS Q BC U MADE IT UP]
Thickness of ___________: minimum 0.7mm; 1.0-1.5. [Metal Framework Design (7)]
exam - remember these three numbers = porcelain !
Which of the following is not a Disadvantage of Porcelain-Fused to metal Crown (metal ceramic crown)? a. Significant tooth reduction: :63-72% by weight. b. Fracture of porcelain: metal coping design and/or fabrication technique. c. Difficult to obtain accurate occlusion due to the glazed porcelain. d. SHADE SELECTION e. INFERIOR esthetics to all ceramic crown. f. Superior esthetics comparing to full metal crown g. Expensive
f is answer bc its an advantage and all rest are disadvantages: • Advantages of Porcelain Fused to Metal crown: - Superior esthetics comparing to full metal crown • Disadvantages of Porcelain Fused to Metal crown: 1. Significant tooth reduction: 63 - 72% by weight. 2. Fracture of porcelain: metal coping design and/ or fabrication technique 3. Difficult to obtain accurate occlusion due to the glazed porcelain 4. Shade selection 5. Inferior esthetics to all ceramic crown 6. Expensive
Which restoration will last longer? This is the restoration type that has more RETENTION (for single-tooth restoration). a. Complex Amalgam b. Metal Inlay c. Glass Ionomer d. Composite Resin e. MOD Onlay f. All-Ceramic Crown g. Metal-Ceramic Crown [red boxed] [Diagnosis And Txt Plan (9)]
f. *Lasts Longest = All metal crown & metal-ceramic crown* The All-Ceramic crown does in fact have good retention, but metal-ceramic is better. Also, the BEST retention is provided by ceramic veneer.
The walls of _____ and ________ grooves can counteract mesiodistal torque resulting from force applied to the pontic. [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
facial and lingual grooves.
[Occlusion And Articulator (10)] the angle between the working and non working paths is greater on teeth located __________ from the condyle
farther
When is an intermediate (pier) abutment used? [Diagnosis And Txt Plan (9)]
frequently occurring situation in which a healthy tooth is located in between terminal abutments to support an FPD. usually max 1st pm & are missing, leaving the max. 2nd PM as pier abutment.
A cantilever pontic can be used to replace a first premolar if ___________ are used on the second premolar and first molar abutments. [Diagnosis And Txt Plan (9)]
full veneer retainers
Color Rendering Index (CRI) [Color Science (2)] [know red]
goes from 0-100. Indicates how well a light source renders color as compared to a standard source (i.e. N. Daylight)
MATERIAL SPECIFIC (red) shade guides should be used for? [Color Science (2)]
i.e. for e.max (lithium disilicate) - high translucency - low translucency - medium translucency - medium opacity. [know: • main crystals found in porcelain (leucite, lithium disilicate, zr) • strength • esthetics]
[Occlusion And Articulator (10)] Distance from CR to protrusion is called? how long? [ must know Occlusal Morphology]
immediate side shift 0-2.6 mm (- If u have immediate side shift, cusps should be shorter. vs... - If condylar guidance is steeper, cusps of molar can be longer. )
Forces on a full-size molar cantilever pontic place great stress on the __________ abutment. [Diagnosis And Txt Plan (9)]
mesial (maybe this is bc of mesial drift?)
For Shade Matching, we want to use what temperature and color rendering index? (know from google doc)
northern daylight = 6500K and is the ONLY light sutable for shade matching. --- We want a temperature of *5,500 and color rendering index of 90*
Which are more yellow - maxillary anteriors or mandibular anteriors? [Know] [Color Science (2)]
o MAXILLARY ANTERIOR TEETH ARE SLIGHTLY MORE YELLOW THAN MANDIBULAR ANTERIOR TEETH (RED). o maxillary central incisors are higher in value than maxillary laterals incisors and canines o no significant differences between color of male and female teeth o with age teeth become darker and more yellow (why?)
you want the combined root surfaces of the abutment teeth to be greater or equal to the missing root surfaces of the_______ tooth/teeth. [Diagnosis And Txt Plan (9)] [MUST KNOW how to analyze an abutment]
pontic
Secondary retention must extend a distance from the primary interabutment axis equal to the distance that the _____________ extends in the opposite direction. [Diagnosis And Txt Plan (9)]
pontic lever arm
Most common complication for POST/CORE is? [know]
post loosening (- Post Loosening 5% - Root Fracture 3% - Caries 2 %)
_____ are temporary or Interim restorations that are placed on the prepared tooth or teeth while awaiting fabrication and placement of the final restoration. a. Acrylic Resin b. Provisional Restoration c. Wax Cast d. Impression
provisional restorations [Provisional Restorations (5)]