OPERATIVE (P2)

Bur used that converges F and L walls in amalgam prep

# 169, 245, 7901

If you feed a person through a tube, then you increase or decrease the risk of caries?

Decrease the risk of caries

What's difference btwn an enamel hatchet and gingival marginal trimmer?

*Both are chisels GMT has curved blade and angled cutting edge (for beveling gingival margins and axiopulpal line angle of class 2 prep) Enamel hatchet cutting edge in plane of handle (plane enamel of the facial and lingual walls of class 2 amalgam prep)

Which tooth will the matrix band be a problem with when placing a two-surface amalgam? to give an idea of the anatomy of the region:

- Mesial Of Max 1st PM (MOST DIFFICULT) > Distal of max molar Mesial on maxillary first molar b/c of the cusp of carabelli

How do cells first attach: dextran or lextran?

Dextran *S. Mutans is involved in converting sucrose --> dextran like long chain polysaccharides (glucans/fructans) using enzyme Glucosyltransferase. This is the main way caries develop.

For an amalgam preparation, the axial pulp should be how many mm into DEJ?

0.2-0.5 mm into DEJ

Diameter of 245 bur ?

0.8

1. Which race has most caries in kid population? 2. Which population has the most number of UNRESTORED caries? 3. Which population has the most caries in permanent teeth?

1. Hispanics 2. Blacks 3. White females

1. DMFT: Who has the most F? 2. DMFT: For adults, who has the most untreated decay, D? white, blacks, Hispanic, Indians

1. White (F) 2. Blacks (D)

Proper pulpal floor depth using Bur 245?

1.5 mm is 3mm, so half of it is 1.5 mm which is proper pulpal floor depth

How do you bevel occlusal floor?(gave list of instruments) a. 13,8 b. 15,80 c. 15,95

15, 80

How far extend pulpal floor in class I amalgam cavity on primary dentition a. 1mm into dentin b. Just into dentin

1mm into dentin

Rotary hand instruments: High speed how many round per min?

200,000 rpm

What bur do you use for peds?

245

What bur use for Amalgam retention in class II?

245 or 330 (Carbide burs are used for cavity prep and performs best at HIGH SPEEDS)

Threaded pin- Amt in tooth/restoration/angulation: What is the optimal depth of the pinhole into dentin?

2mm into dentin Threaded pins used in a dental amalgam restoration should be placed 2mm in depth at a position axial to the DEJ and parallel to the external surface between the pulp and tooth surface Pins should be 2mm into dentin, 2mm within amalgam, and 1mm from the DEJ (to be safe) with no bends in the pins.

Incidence of caries in your office this year is 300 out of 1000, last year it was 200, so what is it for this year?

300-200/1000= 100/1000= 0.1 or 10%

What is ethylene oxide used for in sterilization?

Heat-sensitive instruments

Which is least likely to predict future caries? a. Amount of sugar intake b. Frequency of sugar intake c. Amount of caries and restorations

Amount of sugar intake

Main difference and advantage of using GMT instead of Enamel hatchet? a. bi-angled cutting surface b. angle of the blade c. push/pull action instead of

Angle of blade

Instrument to plane gingival margin on a class II?

Answer has 4 numbers - last number is different. Enamel hatchet is designed to plane enamel of the facial and lingual walls of class 2 amalgam

Where does IP caries (Class II) start?

Apical to proximal contact Below the contact

Leathery brown white lesion? a. acute caries b. chronic caries c. arrested caries

Arrested

If you inadvertently seal over caries what happens? a. Arrested caries b. Extension caries c. Discoloration of tooth d. Micro-leakage

Arrested caries

How do you determine if a patient is at high caries risk?

Assessment

What's characteristic of a remineralized tooth? a) black, dark, bright b) black, dark, opaque c) black, dark, cavitated What are other characteristics?

Black, Dark, Opaque Darker, Harder, More resistant to acid, Shiny

Radiographic decay most closely resemble which zone of carious enamel? a. Body zone b. Dark zone c. Translucent zone d. Surface zone

Body zone

Pit and Fissure caries is described as two cones: a) Two bases are pointing toward the pulp b) Two apexes are pointing toward pulp>>>> in smooth surface (proximal caries) c) One apex toward the pulp and one base toward DEJ d) Both bases facing DEJ

Both bases facing DEJ Base of both triangles lie along the DEJ Triangle point at enamel and base to dentin, dentin base to tip at pulp

Which bur is used to smoothen the prep? a. Diamond b. Carbide

Carbide bur

When do you tx caries/restore lesion: a) half way to the enamel b) through enamel c) when you can see it on xray d) cavitation

Cavitation

Prepped the amalgam, which is INCORRECT? a. cavo surfaces less than 90 degrees b. cavo surfaces greater than 90 degrees

Cavo surfaces is greater than 90 degree

Where are early childhood caries seen the most?

Centrals and Molars

What does DMFT stand for and quantify?

Decayed Missing Filled Teeth *Permanent teeth How the PERMANENT dentition has been affected by dental caries *No 3rd molars *No primary teeth *0-28

Which of the following is the earliest clinical sign of a carious lesion? A. Radiolucency B. Patient sensitivity C. Change in enamel opacity D. Rough surface texture E.Cavitation of enamel

Change in enamel opacity

Days after placed an MOD amalgam, pt present pain in biting and cold, what should you do?

Check occlusion

Application of Chisel: Spoon:

Chisels: Cuts enamel Spoons: Remove caries & Carve amalgams

What type of caries detection is the Dyfoti used for?

Class I Class II, Class III Detection of incipient, frank and recurrent caries, demineralization *DaignoDent = Class I only

What type of caries detection is DaignoDent used for?

Class I/Occlusal caries/Pit fissure caries only *Dyfoti = Class I, II, III

Worst restorative material for ID canine/Class 3 on a canine all are appropriate except: a. Gold b. Glass ionmer c. Composite d. Amalgam

Composite Worst: Composite > GIC> Amalgam> Gold (according to dental decks composite is not given for class 3 DL in canines)

Which of the following is a factor for smooth caries and sugar in-take? a. Consistency b. Amount c. Time

Consistency

Picture of deep amalgam with overhang but it looks really bad why does it look like that?

Corrosion

What does DEFS stand for and quantify?

Decayed Extracted Filled Surfaces *Quantifies how each surface of the PRIMARY dentition has been affected by dental caries

What does DEFT stand for and quantify?

Decayed Extracted Filled teeth Teeth Quantifies how the PRIMARY dentition has been affected by dental caries

What does DMFS stand for and quantify?

Decayed Missing Filled Surfaces *Permanent teeth A more detailed index than DMFT as it quantifies how each tooth SURFACE has been affected by caries.

MC amalgam:

Dispersed phase allow (combination admix: mixture of spherical and comminuted particles)

Which method of sterilization does NOT corrode instruments/dull carbide burs? a. Dry Heat b. Ethylene oxide

Dry Heat

Tx of root surface caries, what kind of dentin should not be restored?

Eburnated dentin (Sclerotic dentin)

What type of Mercury is in the dental office? a. Inorganic b. Elemental c. Ethyl mercury d. Methyl mercury

Elemental

What instrument would not be used to bevel the gingival margin of an MOD prep?

Enamel Hatchet (Gingival margin trimmers bevel gingival margins and for rounding or beveling axiopulpal line angle of class 2 preparations)

What CAN'T you use to bevel inlay prep? a. enamel hatchet b. ging marg trimmer c. flame diamond d. carbide

Enamel hatchet

Mechanism of caries indicator dye:

Enters the dentin and binds to the denatured collagen *A colored dye in an organic base adheres to the denatured collagen which distinguishes between infected dentin and affected dentin) *Stains infected dentin only

Most likely dx indicator of pit and fissure carries is what? a. explorer catch b. xray c. adjacent tooth decalcified d. contralateral tooth thingy

Explorer catch

Patient has a line of separation coronoapical (they won't say vertical fracture on the test), the tooth is asymptomatic and it only hurts when patient eats French bread. What should you do?

Extraction only if moveable pieces. If asymptomatic & not moveable --> Fair prognosis --> RCT

What is the corrosive phase of amalgam? a. Tin/Copper phase b. Tin/Mercury c. Tin/Silver

Gamma2 - tin/mercury Gamma-2 is the weakest phase and the most susceptible to corrosion in the mouth.

Is Sclerotic Dentin softer or harder?

Harder

What is true of Strep. mutans? a. Can live in plaque, b. Can live on gingival c. Can live in a child with no teeth d. Has to live on a non-shedding surface

Has to live on a non-shedding surface

What is the most common site of enamel caries/caries initiation? a) pit and fissure b) at the contact point c) slightly incisor to contact d) slightly cervical to contact

Pit and fissure

Most common reason for failure of dental amalgam: a. moisture contamination b. improper prep design c. improper titration d. improper condensation

Inadequate cavity prep/depth (especially the isthmus area)

Most common fracture of Class II amalgam is seen where?

Isthmus

What contributes to caries formation/progression but is not the primary initiator for caries?

Lactobacillus

Differences between 245 and 330 burs?

Length of the bur 245 = 3mm in length 330 = 1.5mm in length *All other dimensions the same except for length.

What is the correct method of excavation of deep caries? a. Long bur from periphery to the center b. Large bur from center to periphery c. Small bur from periphery to center d. Small bur from center to the periphery

Long bur from periphery to the center

Which amalgam has the most toxic mercury/most hazardous to dentist health? a. Elementary mercury b. Inorganic mercury c. Ethyl mercury d. Methyl mercury

Methyl mercury (organic mercury)

Burs and smoothing out preps? a. More flutes and shallow b. More flutes and deeper c. Less flutes and shallow d. Less flutes and deeper

More flutes and shallow

Acute mercury toxicity for dentists, first signs are? a. nausea b. muscle weakness

Muscle weakness (paresthesia or tremors) Hair loss

Most likely for amalgam to fail? a. Outline cavity design b. Poor condensation

Outline cavity design

What can tell best thing about caries?

Past caries history

Example of a pear shaped bur: Straight fissured bur: Tapered fissured bur:

Pear: 330, 245 Straight fissured bur: 56 Tapered fissured bur: 699

Hydrodynamic Theory of Tooth Sensitivity

Postulates that the pain results from indirect innervation caused by dentinal fluid movement in the tubule that stimulates mechanoreceptors near the predentin

What is the most important etiologic factor in getting caries? a. Saliva pH b. Refined sugar c. Fluoride tx d. Saliva flow

Refined sugar

What do you restore a large MOD in posterior?

Restore with amalgam

Recent survey, what kind of stats on caries/ new data regarding caries shows/which is increasing in the US? a. increase in smooth surf caries b. increase in pit/fissure caries c. smooth surf caries and pit/fissure caries are the same d. increase in root caries

Root caries

Tooth #30 has huge MOD amalgam and is deep. Hurts pt when he eats french bread. What is the cause?

Root fracture

More blades on carbide bur means:

SMOOTHER but DECREASED CUTTING EFFICIENCY

What causes corrosion?

Silver and Tin

What caries lesion has a V shape pointing to pulp? Conical shaped caries w/ broad base with apex towards pulp is commonly seen in? a. Occlusal caries b. Smooth caries c. Root caries

Smooth caries

Difference between smooth (interproximal) vs. pit and fissure (occlusal)

Smooth caries = Apex towards pulp (Conical) Pit & Fissure = Base of both triangles along DEJ (inverted V)

Fluoride works best in what type of caries? a. pit and fissure b. occlusal c. smooth

Smooth interproximal surfaces

How do you diagnose root caries/best indicator? a. sensitivity to cold b. sensitivity to sweets c. soft spot on tooth

Soft spot *Visual and tactile methods are used for detect caries

Amalgam large condenser with lateral condensation is used in what type of amalgam? What type of amalgam needs to be condensed more?

Spherical

What sterilization method is most destructive to burs?

Steam heat

What 3 factors that affect caries initiation?

Substrate Bacteria Host susceptibility

Most Cariogenic? a. Fructose b. Sucose c. Glucose d. Galactose

Sucrose *S.mutans adheres to the biofilm on the tooth by converting sucrose into an extremely adhesive substance called dextran polysaccharide

*Which bur do you NOT use when beveling gingival margins?

Tapered diamond

For a lesion in enamel that has remineralized, what most likely is true? a) The enamel has smaller hydroxyapatite crystals than the surrounding enamel b) The remineralized enamel is softer than the surrounding enamel c) The remineralized enamel is darker than the surrounding enamel d) The remineralized enamel is rough and cavitated

The remineralized enamel is darker than the surrounding enamel

Patient had occlusal amalgam on tooth #30 few weeks ago, one day the dude went to China-town and was having lunch with his homies. He bit down on something and the amalgam broke off. He came back to your office demanding how could this happen with a new filling. What should be crossing your mind?

The prep was not deep enough.

You did a prep with high speed and diamond bur, tooth is sensitive, what is it about bur and handpiece that it caused sensitivity? A) Desiccation B) Traumatized dentin C) Thermal D) Chemical E) Mechanical Most common pulpal damage from cavity prep? What would cause displacement of odontoblastic processes?

Thermal/Heat

More corrosion in which phase?

Tin-mercury phase( gamma 2)

Whats the D__ the one that's only three letter system of tooth carries tracking, what can it not do?

Track how teeth were lost

40 y pt w/ all 32 teeth. No cavities. Has stain & catch in pit of molar. what do you do? a) watch and observe b) sealant c) composite

Watch and observe

Increasing trituration and condensation and decreasing particle size does what? pick 2: a. sets too fast b. decreases setting expansion c. increases setting expansion d. decreases compressive strength

increases compressive strength decreases setting expansion

The cavosurfaces for a prepped amalgam should be greater or less than 90 degrees?

less than 90 degrees

What is wrong with marginal ridge of DO amalgam of #29? All of the following (except maybe)? a. Occlusal wear b. Over carved c. Wedge not placed right

over carved

What are the most common corrosion products found with conventional amalgam alloys?

oxides and chlorides of TIN

Critical pH of developing cavity/when enamel starts to demineralize?

pH 5.5

MOD amalgam with hole why?

poor condensation

Greatest wear on opposing tooth is seen with: a. Amalgam b. Porcelain c. Microfill d. Hybrid composite e. Zirconia

porcelain

A patient has sensitivity in a mandibular premolar. A well- condensed Class V amalgam restoration was placed five months prior with no discomfort for the first four months. Since then, it has become painful. The problem:

probably relates to irreversible pulpal damage

What is the chief function of zinc in an amalgam alloy?

to act as a DEOXIDIZER, which is an oxygen scavenger that minimizes the formation of oxides of other elements in the amalgam alloys during melting.