ENDODONTICS

patient complains of a slight toothache thats been on and off for a week. The tooth in question is #18. Which one of the following would be optimum to use as a baseline? #19 - virgin #15 - primary cavitation on occlusal #3 - fulI gold crown #30 - occlusal amalgam

#19 - virgin EPT checks the sensibility of a tooth by stimulating ncrvc cndings with a low current and high potential difference in voltage. Although manufacturers ofthis device give normal relerence val- ucs ofcurrent, the best way to check "nolmal,/baseline" values is to use it on adjacant t"ron-patho- iogicai) teeth. This is then compared with the values obtained on the looth being questioned. The EPT uses electrical excitation to stimulate the A-delta sensory fibers in the pulp. A positive re- sponse does not provide any information about the health or intcgrity of the pulp: it simply indi- cates that therc are yital sensory fibers present. lmportant: The EPT fails to provide any informalion about the vascular supply to the pulp, which is the truc determinant ofpulp vitality. Note: EPT is not considered reliable in the following conditions. 1. A pus-fillcd canal 2. A nervous patient .1. Recent dental trauma - - t'alse positivc false positive lalse negatire 4. hsulating rcstoration - false negative 5. Sccondary dentin deposits 6. Moisturc (ontaminalion 7. lmmature tooth t'open - - - apex) 8. Patient who has taken analgesics falsc negative [alsc positir c - false negative - false negative lmportant: Never wear gloves while using the EPT as this impcdes conrpletion and results in a false-negative response. Also, ifa paticnt's medical history reveals that a cardiac pacemaker has been implanted, the use ofan electric pulp tester is contraindicated. Response to EPT: . Acute pulpitis: lower than normal current, as acute inflammation mediators lowcr the pain thrcshold . . Hlperemia: lower than normal, but higher than that seen in acute pulpitis Pulp necrosis/abscess: no response at any currenGlevel

A patient presents with pulpal pathosis. Your assistant hands you an xray which shows no evidence of any restoration or caries. At first you dont believe that the xray is from the right patient but it is. This scenario is pathognomonic of Condensing osteitis A vertical fracture of the tooth Periodontal abscess Secondary occlusal trauma

A vertical fracture of the tooth Radiographic examination seldom reyeals the fracture because the crack is usually parallel to the x-ray film. One of the most puzzling and frustrating dental conditions involving the possible need for endodontic treatment is the cracked tooth syndrome. Symptoms from this condition usually are characterized by a sharp but brief pain occurring unexpectedly only when the patient is chewing. Having a patient bite forcefr.rlly on a bite stick and noticing the cusps that occlude when the pain occurs will aid in the location ofthe olTending tooth. In most cases there is an isolated probing defect at the site offracture. An important diagnos- tic sign is a radiolucency from the apical region to the midline of the root teardrop-shaped). Vertical fractures through rcot structure, however, have an almost hopeless prognosis. lfthe fractured segment can be removed and gingivoplasty and alveoloplasty per- fbrmed, treatment can be successful. However, unrealistic or overambitious case selection leads to a high degree offailure. When an anterior tooth fractures, it generally occurs in a more horizontal plane and may show up on the x-ray. The cause is usually accidental tnuma such as a blow to the teeth. If the fracture line is not too far down the root ofthe tooth. it mav be able to be saved with a root canal and a crown. lmportant: Inlays have been shown to be a cause offractures. lfa patient complains ofpain on mastication since the placement ofan inlay, suspect a fractured cusp help detemtine v'hiclt cusp may be fracnred). Itiote: Chronic focal sclerosing osteomyebtrs (condensing /asltg oJleillt is excessive bone mineralization around the apex ofan asymptomatic, vital tooth. This radiopacity may be caused by a lo$.erade puip initation. This process is asymptomatic and benign and does not require root canal therap!.

About what % of mandibular first premolars may have two canals with two apical foramina? 5% 20% 45% 65%

20% Almost one fourth ofall mandibular first oremolars mav have two canals with two foram- ina. The treatment of mandibular first premolars can really be tricky! At least 27oA may have two canals with either one or two fommen. This is quite different from the mandibular second premolar are found to have one canal with one foramen. The second premolar has fewer variations than the fimt premolar, usually having one root and -867o one well-centered canal. The access opening is oval. Consideration must be given to the men- tal foramen which lies in close proximity to the apex. Avoid overinstrumentation and over- fill. When viewing an x-ray ofthis area, the mental foramen is sometimes misdiagnosed as a premolar abscess. Therefore, before performing root canal therapy, make sure all diagnostic tests confirm your finding. Note: Ifa straight-on preoperative radiograph ofa mandibular first premolar shows the pulp canal disappearing (or goingfrom dark lo /r'g@ in midroot, this is an important indication that two canals are present Other diagnostic tests: . S€lective anesthesia test: can be used when other tests have not determined which tooth is the source ofpain. . Test cavity: only done in cases where a strcng suspicion ofpulp necrosis is present and confirmed with other tests and radiographic findings, but a definitive test is requircd. Remember: A radiolucency will not begin to manifest until demineralization ofbone extends point: You should not rely exclusively on x-rays in an anempt to anir e at a diagnosis. through the cortical plate ofthe bone -Key lmportant: Because an x-ray is only a two-dimensional image, two films ofthe tooth or teeth in question should be taken at the same vertical angulation but with a 10- to l5-degree change in horizontal ansulation.

A periodontal probing defect which may not be managed by endodontic treatment alone is A conical shaped probing A narrow sinus tract type probing A blow-out type probing None of the above

A conical shaped probing *** In "blow-out type" and "sinus tract type" probings, another clue for diagnosis is a non- vital (necrosed) pulp - these two lesions can completely heal after root canal treatment. Acute or blow-out lesions: a tooth with this type oflesion will show normal sulcus depth all the way around the tooth until the area ofthe swelling is probed. At this point, the probe drops suddenly, to a level near the apex. The probing depths in all other areas are within normal lim- rts. Periodontal lesions characteristically show bone loss which begins at the crestal bone level and progresses apically. Hence probing defect would be conical in shape. This type of lesion may not be amenable to root canal treatment alone even if it is associated with a pulpless tooth. However, endodontic treatment must be completed prior to tackling the periodontal problem. A narrow sinus tract type lesion: the probing reveals nomra) depths al) around the tooth ex- cept at one very narrow area. Here, the probe can pass down the root surface to some distance and sometimes even to the apex. The tooth is pulpless (non-itel.). Once the root canal treat- ment is completed, the lesion heals within one week. i'r"ote; All sinus tracts should be traced rvith a gutta-percha point by radiograph. Remember: A perio-endo abscess is a combined lesion. The lesion usually demonstrutes ra- dioeraphic involvement ofthe periodontium and the apex ofthe involved tooth. Important: To distinguish a periodontal lesion lrom an endodontic lesion, pulp vitality tests alLrng $ ith periodontal probing are essential. \ote: A common clinical finding ofa periodontal problem is pain to lateral percussion on a tooth rrith a wide sulcular Docket.

Which of the following is the most characteristic evidence of a vertical root fracture? A persistent periodontal defect A radiolucent halo surrounding the root of the fracture A radiopaque lesion at the sight ofthe fracture A visible fracture when transillumination is used

A radiolucent halo surrounding the root of the fracture Often times transillumination is used to see the defect, but ofcourse, this cannot be diag- nostic on tooth structure that is under bone. Also, persistent periodontal defects are often caused by vertical root fractures; however, this is not radiographic (read the question carefu I I1') . Important: Radiographs tures. lwltlrout.lirst wedging the lootiT rarely will show veftical frac- Vertical fractures will often be recognized radiographically by their effect on the bony attacirment apparatus that is seen as a diffhse radiolucency or "halo" surrounding the root. This can be differentiated from other periapical radiolucencies because it surrounds the tooth uniformly ratherthan being located at the portal ofexit ofthe apical foramen or lateral canal. l. A tooth with a vertical fracture through root structure has a poor progno- \otes sis.2. Studies have indicated that most vertical root fractures are caused by too much condensation force during obturation with gutta-percha. Therapy for horizontal fractures of the root always involves considerable difficulty. Root canal treatment is not indicated if the fracture sites remain in close proximity and ifthe pulp retains its vitality. However, ilclinical symptoms develop or the segments appear to be separating according to the x-ray, some treatment is necessary. Remember: Root fracture can only be visualized on a radiograph if the x-ray beam passes through the fracture line. As the fracture line could extend diagonally, an additional radi- ograph is taken with a 45" (steep) vertical angulation in addition to the conventional 90"

Tooth # 9 requires root-end surgery. Which flap design is generally NOT indicated? . A submarginal curved flap (semilunar) A submarginal scalloped flap (Ochsenbein-Luebke) A fulI mucoperiosteal flap (triangular, rectangular, trapezoidal, horizontal) None of the above

A submarginal curved flap (semilunar) This half-moon shaped flap is raised with a curved horizontal incision in the mucosa or attached gin- gival with the concavity towards the apex. Although it's simpie and does not impinge on the surround- ing tissuc, thc disadvantages outweigh its advantages. These include: . . Limited access and visibility Tcaring of comeN ofthe incisions when an attempt is made to improve accessibility by stretching the flap . Ifsomehow a lesion is found to be bigger than anticipated, the incisions come to lie over the bony defect . Its extent is also lirnited by anachments *** 1/e.g.,.fienum, muscles etc.) Tlterefo.e, this tcchnique is not used for anlerior root end surgery. Surgical flaps on the basis ofhorizontal incision can bc classificd into tr}o major typesi L Full mucoperiosteal flaps: . . Triangular (one vertical releasing inci.sion) Rectangular /ano t,erlical reledsing incisior.t 2. Limited mucoperiosteal flaps: . . Strbmarginal cuned Submarginal scallopcl (Senihnar) Oc hsenbei n- Luebke) The submarginaf scalloped ( . . Trapezoidal (brctal hased rcctanguldr) Horizontal /ro rcfiical rcleasing incisions) (Ochsenbein-Le!6te, tlap requires at least 3-5 mm ofattached gingiva and a hcalthy periodontium. It is raised by a scalloped incision in the aftached gingiva with onc or two ver- tical incisions. Less risk ofincising over bony defects and no post-surgical recession ofgingiva. Its dis- advantages includc hcmorrhagc from the cut margins and scarring. Access and visibility is better acceptoblel than semrlunar flap but not as good as full mucoperiosteal flap. Full mucoperiosteal flaps allorv maximal access and visibility. They are raised from the gingival sul- c\rs (ele\!ting gingirdl crest and interdental glrg,?,/. This wide outliI1e ofthe flap prccludes any inci- sions o\'cr bonv defects and allows various periodontal procedures including curettage. root pianing and bone re-shaping. A large flap may be difficult to reposition, suftrrc and makc alterations. Posr surgical gin- si\ al recession is also a oossibilitv.

Which two of the following situations offer better success for pulp capping? Accidental exposue of the pulp Pulp of a middle-aged person Carious exposure of the pulp Pulp of a young child

Accidental exposue of the pulp Pulp of a young child Pulp capping is the placing of a sedative and antiseptic dressing on an exposed healthy pulp in order to allow it to recover and maintain normal function and vitalit),. The dressing most com- monly used is CaOH2 (Dycal). Pulp capping is overuscd in dcntistry today. ln reality it has only very l-ew indications for its use. Young pulps are morc vascularized and. therefore, more amenable to repair. Pulp cappjngs are more successful if the exposure was acc idental (trduma or \r ith a de - la1Dr, as opposed to carious. ln addition, the exposure should only be pinpoint lo expecl succcss. Repair is accomplishcd by the formation ofa dentin bridge at the site ofexposure. Evcn a snall carious cxposurc should have root canal therapy for thc best long-term prognosis. Note: Direct pulp capping is indicated ifthere is a small mechanical exposure traLtmatic expo.\ure), an asymptomatic vital pulp, and no coronal or periapical pathology. A hard tissuc bar- ricf (repuratlw dentin bridge) may be visualized as early as 6 weeks postoperative. Atooth may stay asymptomatic for scveralweeks after pulp capping has bccn pcrformcd. However, this may be only tenrporary. Unfortunatcly, if pulp capping I'ails and the tooth becomes sympto- matic, it may be difficult, ifnot impossible, to treat with routine endodontics because oflhe severc calcifications in the root canal. Perforations may occur during attempts to follow the obliterated canal to gain palency to the apex. Note: Perfo.ations into lurcations ofmulti-rooted tecth havc the poorest prognosis. Indirect pulp capping involves removing infccted dentin almost up to the point ofpulpal expo- sure. Calcium hydroxide is placcd and then a resin modified glass ionomer cement is placed over that. Formation of secondary dentin should occur and then a final restomtion is placed alicr rcmoval ofthc internlediate restoration and rcsidual carics. Thc goal ofindirect pulp capping is to havc thc tooth participale in ils own recovery. Indications for indirect pulp capping include deep carious lesions that encroach but are not actually in the pulp, no history ofchronic pain, no radiographic pathology'. r'ital pulp. and normal looth mobility and color

In which of the following scenarios would you consider using solvent softened custom cones? Lack of an apical stop An abnormally large apical portion of the canal An irregular apical portion of the canal After an apexification procedure All of the above

All of the above Ifthe preparation is properly flared, fitting the master cone is not a time-consuming pro- cedure. A gutta-percha cone the same size as the file used last durin gpreparation (MAF) is selected and placed as far as possible into the canal, but not beyond the working length. Once satisfactory tugback and apical positioning appear to be obtained, a radiograph is taken to verify cone positioning. If an accurate determination and careful enlargement have been performed, the x-ray will show that the master cone reaches the most apical position of the preparation or extends to a point just short of that ( cone is slightly short, the pressure ofcondensation plus the lubricating action ofthe sealer * ill be sufficient to produce complete seating of the cone. \rl3es for.snall I nm). When the L If the cone is more than I mm from the radiographic apex, discard the cone and fit a smaller one or instrurnent more in the apical third. . 2. Remember: The main reason for recapitulation inct euse in .;file lirirgl,our MAF after eqcll size) during instrumentation of the canal is to clean the apical segment ofthe canal ofany dentin filings that lrere not removed by irrigation. 3. Common solvents used to soften gutta percha are chloroform, methylchloro- formate, halothane, rectified white turpentine, and eucalyptol. 4. Studies show that solvent softening does not ultimately result in a better api- cal seal. 5. Slight resistance to dislodgement is refened to as 6. The cone should also have a delinite apical seal be pushed further apicall,. 'itugback.r' - it should not be able to

Which of the following are acceptable methods to clean Push and pull stroke Reaming motion Engine-driven rotary motion All ofthe above

All ofthe above The engine driven instruments, however, use only the reaming motion. Nickel tita- nium instruments can be both hand operated and engine-driven. Generally, hand instrumentation is done by either filing (push and pull) or reaming peated rotqtions). Filing is a push-pull action with emphasis on the withdrawal stroke. Its efficiency is great- est with fil€s than with reamers for removing dentin because of the greater number of flutes in contact with the canal walls during the rasping motion of removing the instrument. Filing action produces an irregularly shaped canal and therefore must be filled with gutta-percha in a condensation procedure. Reaming is defined as the repeated clockwise rotation of the instrument, particularly during insertion. Reaming produces a canal that is round. Reaming is recommended if using a silver cone to fill canals. Circumferential filing is a push-pull action with emphasis on scraping the canal walls to create a smooth, tapered preparation. It is a method of filing whereby the instrument is moved first towards the buccal side ofthe canal, then reinserted, and removed slightly mesially. This is done all the way around the tooth until all the dentin walls have been planed. This technique enhances preparation when a flaring method is used.

Which is the most accurate definition of a phoenix abscess An acute apical periodontitis A suppurative apical periodontitis An asymptomatic periapical granuloma An acute exacerbation ofa chronic apical periodontitis A chronic state ofan acute apical periodontitis

An acute exacerbation ofa chronic apical periodontitis A phoenix abscess is also known as a recrudescent abscess. lt develops as the granulo- matous zone becomes contaminated or infected by elements from the root canal. Diagnosis is based on the acute symptoms fparn /o perc'ussion) plus radiographic examination, which reveals a large periapical radiolucency. Note: A phoenix abscess is always preceded by chronic apical periodontitis. Signs and symptoms are identical to those of an acute peri- radicular abscess, but a radiograph will show a periapical radiolucency that indicates the presence ofa chronic disease. Not€: The term "Phoenix Abscess" is becoming obsolete. The term replacing it seems to be "an acute exacerbation ofchronic apical periodontitis" (yes, the delinition is no\r the term). A granuloma is defined as a growth of granulomatous tissue continuous with the peri odontal ligament resulting from pulpal death with diffusion oftoxic products into the pe- riapical area. ln most cases a granuloma is symptomless. Radiographically, one sees a well-defined area ofrarefaction with some inegularities, while clinically the tooth is not sensitive. A massive invasion of pulpal contaminants will result in the formation of an acute abscess (Phoenix abscess). A cl st is an inflammatory response of the periapex, which develops from preexisting granulomatous tissue (granuloma). It is characterized by a central, fluid-filled, ep- ithelium-lined cavity, surrounded by granulomatous tissue and peripheral fibrous en- capsulation. It is often associated with a chronically infected tooth. The tooth may be mobile. On radiographs. one will see a well-defined area of rarefaction (radiolucency) ivhich is limited by a continuous radiopaque, sclerotic border olbone. It is usually asymp- tomatic. Important: A granuloma or a cyst can only be diff€rentially diagnosed by histological eramination.

In which of the following cases could a dentist choose not to perform root canal therapy although it is advised? On a non-restorable tooth On a periodontally insufiicient tooth On a tooth with a vertical root fracture On a asymptomatic tooth with a calcified chamber On a tooth that is not in occlusion On a tooth that has massive extemal resorption

On a asymptomatic tooth with a calcified chamber ln all thc othcr sccnarios. root canal therapy is contraindicated. Other contraindications include: . . A non-strategic tooth -a tooth not in occlusion A tooth with massive internal or external resorption .A tooth that has a canal unsuitable for instnlmentation or forsurgery /i.e., broken instnrnents, dentina l sc lerosi|;, s hat p d[l a. erations, etc..) A medical condition such as hcmophilia is not a contraindication to convcntional endodontic ther- apy. However, it is strongly recommended that a dcntist obtain clcarance from the patient's physi- cian prior to trcatmcnt. Thc only systemic conlraindications to endodontic thcrapy are uncontroffed diabetes or a very recent myocardial infarction (v,ithin tlte post 6 months). Note: Example of a special case: A previously traumatizcd looth may show complcte obliteration ofthe pulp chamber and canal. The periodontal ligament may appear non'nal. The pa- tient will be asymptomatic and the tooth will not respond to pulp vitality testing. The trcatment of choice is to obsene as long as the tooth remains asymptomatic and no periapical changes arc cv- rdent. Fracture injuries: . . . Infraction: an incomplctc crack ofenamel wilhout thc loss oftooth structluc Enamel fracture frIis Class I)t involves enamel only: no pulpal involvemcnt Enamel and dentin fraeture (Ellis tnent . Cla.t,r 1/): involves enamel and dentin; no pulpal involvc- Class III): pulpal trcatment depcnds on stage of developrnent oi' tooth Enamel and dentin fracture with pulpal involvement (immatrre ft1lr.r $ msture) and ti]me after traumatic injury /lfter 21 hours the chances ol direct bacterial contdmii.ttion increase) . Root fractures: prognosis dcpcnds on location; coronal root liactures ha!c a n]idroot fracturcs havc guarded prognosis and apical root fractures havc the bcst prognosis Important: Prognosis improves as liacturc approaches apex: horizontal is better than vertical; nondisplaced is bctter than a displaced fracturei and oblique is bettcr than transversc.

A seven year old boy arrives at the office with a complaint that tooth #8 is draining pus into his mouth, The tooth had been traumatized earlier The vitality tests reveal no response. What is the treatment ofchoice? Extraction Apexogenesis / pulpotomy Root canal treatment Periodontal surgery to remove sinus tract It is only necessary to give the child analgesics and antibiotics for pain and infection . Apexification

Apexification Ap€xification is a technique whose goal is to induce further root development in a pulpless tooth by stimulating the formation of a hard substance at the apex, so as to allow obturation ofthe root canal space. Apexification may be rcquired afler pulpectomy as at seven years of age the apex ofthis tooth must be open. Remember: Apex closes 2-3 years after emption. The technique consists ofisolation ofthe field with a rubber dam, making an access cavity and removing all pulpal tissue by the use ofreamers and files. A premixed syringe of a calcium hydroxide-methyfcellulose paste (/or erample, a Pulpdent s.vrlrge/ is injected into the canal until it is filled to the cervical level. The paste must reach the apical pofiion ofthe canal to stimulate the tissues to form a calcific barrier. A double seal ofcement is made to close offthe access cavity. The patient is recalled after three months to see ifapexification has taken place. Ifnot. a liesh supply ofpaste is placed. lfapexification has occurred, conventional root canal therapv is instituted. The action of calcium hydroxide in promoting formation ofa hard substance at the apex is best erplained by the fact that calcium hydroxide creates an alkaline environment that pro- rnoles hard tissue deposition. Note: Its high pH (pH-12.5) also causes an antibacterial ellect rnd it inacli\ ate: lipopolysacchande. \ote: Ifa permanent tooth fractures and has a fully formed root and the pulp is exposerJ, (large erpasure). the ffeatment of choice is complete root canal therapy. Apexification is not needed because the root is fully fonned. lf the exposure is small and the length of time is I /2 hour to I hour), then a direct pulp cap with CaOH lbllowed by a restoration is the ireatment short ( (|fchoice. Remember: Apexogenesis is the process of maintaining pulp vitality during pulp treatment to allow continued development of the entire root. As opposed to apexification, this proce- dure relates to teeth with retained viable pulp tissue in which this pulp tissue rs protected, treated, or encounged to permit the process ofnormal root maturation.

Retreating a tooth with a post is the most common reason for an apicoectomy and retrograde filling, Whenever a reverse lilling procedure is to be used, apicoectomy is mandatory to provide a table into which the preparation and filling will be placed. The first statement is true, the second is false The first statement is false, the second is true . Both statements are true Both statements are false

Both statements are true An apicoectomy is thc prcparatior ofa llat surfacc by thc cxcision ofthc apical portion qucnt rcmoval ofattached soft tissucs. ofthc root and any subsc- Ifa toolh has had previorrs endodonlic lherapy and becomes reinfectcd, il is usually bcst lo try and .etreat it con' vcntionally remove filling marerial, debride the canals, and rcfill. However, iltbe tooth has bccn restorcd $ith a post, corc. and crown thcn apical curcttagc, apicocctomy, and a rclrotill should bc tooth with a post is the most common rerson for an apicoectomy and retrograde fllling. Indications for apicoecaomy (root-e . A rcvcrsc filling nccds to bc . n d rc se c tion placcd ll is ncccssary to gain acccss to an area ofpathosis ) | . Thc poorly fillcd apical ponion oflhc root is to be rcmoved to the levcl ofcanal obliteration . . pcrformcd. Note: Rctrcaling a Non-ncgotiablc canal, blockagc or scvcrc root curvaturc in wbich non-surgical trcatrnc t is impossiblc Complications arising fiom proccdumi accidcnts $hich cannot bc handlcd withoul surgical cxposurc ofthe sitc . . . Failcd rcatmcnt duc to inetricvablc posts or root fillings (e.9., separat ion of instrumentt, ledsingai /or pertrrruliot$) Horizontal apical liacturcs in which apical cnd ofthc pulp bccomcs necrotic Biopsy . to diagnosc non-odontogcnic causcs of symptoms &.9., nancr, Iip paresthesid or anesthpsia) Contrsindications for api.oectomy (rcol-end rcsection): . Anatomic factors that limit acccss crown/root ratlo Procedure: . . Mcdical or systcmic complications p.rlient *ilh a histotr . 4 pre|ious nalig- Toolh is nonrcstorablc or has a Radiographs are taken to determine the length ofthe root and ils proximity to adjacent structurcs . . Administer anesthesia On th€ labial surfacc ofthe tooth, witb the help ofa pcriostcal elcvator. locatc the root apex, so that an incision can bc madc . Flap designs used: submarginal scallopcd . Reflect the flap fO. ltsenbein- l,uehke) , ^nd t! I I m ucoperiosteal flaps . Root apex is exposed, thcn apcx is cut olf with a lissure bur about one-third of its lcngth . Curette the surrounding . . pathologic tissucs and round ollthc end of thc cut rool For retrograde filling, a bevel of0-10 dcgrccs is grvcn Retrograde filling to I mm is donc . Irrigate the wound Nnd ruture the llap in position

There are multiple techniques for internal bleaching Hydrogen peroxide is a key ingredient for all of them The first statement is true, the second is false The first statement is false, the second is true Both statements are true Both statements are false

Both statements are true Hydrogen peroxide is the most effective bleaching agent; used in concentrations of 30-50%. lt is best delivered in an alkaline medium. Superoxol is a 307o aqueous solution by weight ofhydrogen peroxide in distilled water. It is potent oxidizing agent whose bleaching effect results from direct oxidation ofstain- producing substances. Chairside technique: Application of heat to Superoxol-saturated cotton pellets in the tooth chamber Repeat until tooth is lighter Note: The heat liberates the oxygen in the bleaching agent. Important: . Cervical root resorption relating to bleaching is a potential side effect; usually it does not manifest for at least 6 months. This is a reason why recall appointments are lmponant. . The most probable postoperative complication of bleaching a tooth that has not been adequately obturated is an acute apical periodontitis. . Tooth bleaching causes a color change in both enamel and dentin. \lalking bleach technique: uses a mixture ofsodium perborate and water and may be utilized ifthe chairside results are inadequate or ifyou prefer to avoid the possibility ofa higher chance ofcervical root resorption. Place a thick paste in the tooth chamber with a temporary restoration for four to seven days. Several repetitions of this procedure can work quite well. The sodium perborate when fresh is 95olo perborate giving off 9.9% of available oxygen. This material is more easily controlled and safer than Superoxol; there- fore, it is the material ofchoice.

A mandibular canine typically requires an oval access preparation The access should be directly slightly towards the lingual surface due to slight labial axial inclination of the crown The first statement is true, the second is false The first statement is false, the second is true Both statements are true Both statements are false

Both statements are true Mandibular canines usually have only one root but in rare cases may have two separate roots. The access opening is a large oval with the greatest width placed incisogingivally. This tooth usually has a slightly labial axial inclination of the crown, therefore the ac- cess opening needs to be directed towards the lingual surface. The canal ofthe mandibular canine is somewhat ovoid at the cervical area but it becomes rounder at the apex. \ote: The root canal for a mandibular canine is thin mesiodistallv but wide labiolin- guall)'.

The action of using a file often dictates the shape of the canal A reaming action produces a canal thats relatively round in shape The first statement is true, the second is false The first statement is false, the second is true Both statements are true Both statements are false

Both statements are true Studies have shown that the action of using thc instrunent, rather than the instrument used, determines the general shape ofthc canal preparation. Therefore, a reaming action produces a canal thal is relatively round in shape while a filing action produces a canal that is irregular in shape. Important: A canal should be instrumented and shaped so that it has a continuously tapering fun- nel shape. The widest diameter would be at the canal opening and the narrowest at the dentinocemental j unction to and fillcd to aJ I o L0 mm fideal/r. from the radiographic aper). This is where all teeth should be filed The common methods for sterilization uscd in cndodontics are: . 2 1/o Glutaraldehyde: - Cold or heat-labile instruments such as rubber dam frames. etc. - Generally, 24 hours are required to achieve cold sterilization. - Least desirable mcthod. . . . Autoclave: - Instrurnents should be wrapped and autoclaved for 20-30 minutes at 250' F psi. - This *ill kill all bactcria, sporcs and viruscs. Dr-v heat sterilization: - Is supcrior for sterilizing sharp-edged insltruments (hand instruments, reamers, broaches, D&ri. etc.l to best preserve their cutting edges. fles, - Temperature is 320" F (160" C) fbr a minimum of I hour - Dry heat is effectivc as a stcrilizing agcnt becausc the resistancc ofproteins to heat denatF ration decreases as they dry. Hot salt {or beads): - Bead sterilizers are receptacles that heat contents to approximately 45O" F (232" C). - lntracanal instruments (iles, reamers, broaches, etc.) shouldbe stcrilized by immersion in the salt for 5 seconds.

Regarding the restoration of endodontically treated teeth, all of the following are generally regarded to be true except one. A major disadvantage of posts/dowels is that it does not reinforce the tooth structure, in fact, it weakens it All post designs are predisposed to leakage At least 4 mm ofgutta-percha must remain to preserve the apical seal Threaded screw posts are preferred over parallel sided and tapered posts Pins add to stresses and microfractures in dentin and should not be used Cusps adjacent to lost marginal ridges should be restored with an onlay

Threaded screw posts are preferred over parallel sided and tapered posts *** Thesc may actually increase the chance offracture. The parallel-sided posts are prefened. Options availablc whcn restoring endodontically treated posterior teeth: . R€storation ofocclusal opening only: in rare instances thc access opcning and ca es destnrction do not encroach on the cusps and marginal ridges. These teeth may be restored with an occlusal amal- garr; however, a cuspal coverage restoration would provide protection from fracture. . Onlay restoration: in most cases it is imperative that root canal treated t€eth b€ protected from fracture by a cusp-coverage qpe ofrcstoration. The minimum (ra ost conserwtiv) preparation should be for an onlay' covering the cusps and marginal ridges. . Cro$n: a full-coveragc crorvn is prcfcrred whcn the rcmaining coronal tooth strucrurc does not af- ford sull'icicnt tooth structure for an onlay. . Cro$n $ith post and core: to reinforce the treated tooth and provide suitable coronal tooth strxc- mre for an optimum crown prcparation, thc usc of a post and corc is often indicared. Be very careful $ hen placing posts. Perforations and vertical root fractures can occur. Important: The primary purpose ol the post is to rctain a corc in a tooth whcn thcrc is an cxtcnsivc loss ofcoronal tooth struc- rure Posrs do not reinforce the tooth, but further weaken it. At least 4 to 5 mm ofremaining guna-percha is recomnended. \otes .., _i::!_': 1. Ifyou arc performing a pulp chamber-retained amalgam, you need to placc amalgam 3 mm inro each canal for retention. l. Endodontically trcatcd postcrior tccth arc morc pronc to fracturc than Llntreated postedor teeth due mainly to the destruction ofthe coronal tooth structure tural integrity. -they have reduced struc- 3. More endodontically treated teeth are lost because ofrestorative factors than failure ofthe root canal treatment itsclf. 4. Pemanent restorations arc bcst placcd ASAP after obturation to seal the intemal aspeot of thc tooth from contamination. 5. Endodontically heated teeth do not become brittle. The moisture content ofcndodonti- cally treated teeth is not reduced even after l0 years. Key pointi Tccth are weakened by thc loss of tooth structure.

Internal resorption of a tooth is generally believed to be caused by inllammation due to an infected coronal pulp. This condition is frequently caused by traumatic injury to the tooth The first statement is true, the second is false The first statement is false, the second is true Both statements are true Both statements are false

Both statements are true lnternal (in;flammalory) resorption is usually asymptomatic and is discovered on routine radiographic evaluation. The anatomic configuration of the root canal is altered and in- creases in size with intemal resorplion. It will appear as an inegular radiolucency anywhere along the canal space. The tooth involved may respond to pulp vitality tests. When intemal resorption is detected, a pulpectomy should be performed. Once the pulp tissue responsible is removed, all resorption ceases. To "wait and see" may result in sufficient destruction ofthe tooth to create a Derforation ofthe root. Internal resorption of maxillary right lateral incisor. \ote: Although, intemal resorption can occur only when some of the pulp tissue is still lital. a negative sensitivity test does not rule out this etiology. Also remember that sometimes on a radiograph, an extemal resorptive lesion can superimpose the canal space to mimic intemal resorption. In such cases, another radiograph should be exposed at an angle to the tooth. The radiolucent lesion inside the canal space will not shift.

Broaches are not used for canal enlargement because they are made of stainless steel. Both the statement and the reason are correct and related Both the statement and the reason are correct but NOT related The stalement is correct, but the reason is NOT The statement is NOT correct, but the reason is correct NEITHER the statement NOR the reason is correct

Both the statement and the reason are correct but NOT related The rcason broaches are not used for canal cnlargcmcnt is not becaus€ they are made ofstainless stccl. it is lheir design.The barbs are notchcd out of the instrument shaft and rcpresent a weaken€d point. If the broach is not used with the utmost of car€ or il it is forced apically, the barbs will be bent and will engage the walls, making removal difficult. It is not used for canal enlargemenf. K-type instruments: . Files are lhe most uscful instruments in eDdodontics fbr the removal ofhard tissue in canal enlargements. They arc manufactured by t$isting a blank, which is a square rod. producing a series ofcutting fluies. The action uscd for placing this type offile into a canal should rescmble a clock \1 ise-counierc lock*,ise motion with pressure dircctcd apically (tan he a.filing or reaning action). Note: These files are the strongest of all files ancl cut the least aggressiv€ll. A modification to this tlpe oftlle is the K-fl€i file. . R€amerc are manut'actured in a manncr similar to files. only they have fe*er flutes. They are used in canal preparation to shave dentin and enlarge cmals \r,ith a rcaming action only, They remove intracanal dcbris with clockrvise reaming action. They arc also uscd to place materials into the apical ponion of the canal by using a counierclocklr'is(] rotatlon. H-type instruments: . H€dstrom files are manufactured by using a sharp, rotating cutter to gauge triangular s€gments our ofa round blank shaft. This produces a very sharp edge and thereforc an cffective cuiting insrument. Ifused care- tully, lvith filing action only, it \\'ill successtully planc rhc deniin *alls much faster than K-rype files or reamcrs. A modification oflhis filc is the S-file. \ote: All ofthe above are made ofsteinless st€el. File dimenrions: The position at which the cutting bladcs begin on an instrument is called Dl, aDd thc flutcs .\tcnd up rhc shafl fbr 16 mm to stop at D2. The remaining portion ofthe shaft extendiig io the handle has no llutes. and its length is the difference between 16 mm. and the lotal lcngth from lhe tip to the handlc. The leneth of cunin.e edgcs lthe distance beteee D t a d Dt remains l6 mm, regardless ofthe lcngth or style of Ihc i:sirument. The numbcring svstem for instrument identification is based on the diameter at Dl, stated in hurdredths of millimeters. Therefore the name ofeach instrumcnt givcs considerable inlormation about its di- merioni Asjzel0fleisindicatedtobe0.l0mminwidthatDt and . l0 mm plus 0.30 mm 3 lornt 16 mm f'arther up the shaft fDr, etc.

Which of the following is not suggested to be used for irrigation of a canal during root canal therapy. Urea peroxide (Gly-Oxide) Hydrogen Peroxide Sodium Hypochlorite Calcium Hydroxide

Calcium Hydroxide *** Calcium hydroxide is not an irrigant. Sodium Hypochlorite is the most widely used irrigant and has effectively aided canal preparation for many years. A 5.25olo solution provides excellent germicidal solvent ac- tion, but is dilute enough to cause only mild irritation when contacting periapical tissue. NaOCI is a good tissue solvent as well as having some antimicrobial effect. It also acts as a lubricant for root canal instrumentation. Note: lt is toxic to vital tissue; always use rubber dam. Note: To date there is no agreement on any single concentration-value of sodium hypochlorite H"vdrogen peroxide (396 Q"taOCl) as being the most effective while being the safest. solution) is also widely used in endodontics with two modes of action. The bubbling of the solution when in contact with tissue and certain chemicals physically foams debris from the canal (efJbnescent eflbcf. In addition, the liberation of oxygen uill destroy strictly anaerobic microorganisms. The solvent action of hydrogen peroxide is much less than that ofNaOCl. However, many cljnicians use the solutions al- temately during treatment. Urea peroxide is available in an anhydrous glycerol base, as Gly-Oxide, to prevent decomposition and is a useful irrigant. It is better tolerated by periapical tissue than NaOCl. yet has greater solvent action and is more germicidal than hydrogen peroxide. Therefore, it is an excellent iffigant for treating canals with normal periapical tissue and ri,'ide apices. The best use for Gly-Oxide is in narrow and/or curved canals, utilizing the slippery effect of the glycerol. Note: Irrigants perform the important biologic function of destroying bacteria during endodontic therapy. Their action is unquestionably more significant than that supplied by the use ofintracanal medicaments. Irrigants should be used copiously throughout the in- strumentation phase ofroot canal procedures.

Which 3 of the following are related to vital teeth and usually do not warrant endodontic therapy Apical scar Cementoma Traumatic bone cyst Globulomaxillary cyst Radicular cyst Chronic dental abscess Chronic periapical granuloma

Cementoma Traumatic bone cyst Globulomaxillary cyst An apical scar is represcntcd by a periapical granuloma. cyst, or abscess that heals with scar tissuc. Well-circumscribed radiolucency resembling a granuloma. Tooth is non-vital. A radicular cyst usually occurs in a pre-cxisting granuloma. Scldom is painful. Radiolucency at apcx ofnon-vital tooth. A chronic dental abscess is often a result of a periapical granuloma. Radiolucent area at apex ofnon- Iital tooth. Fistula is often found leading from an abscess caviry Once drainage is establishcd, thc tooth stops being painful. Note: A chronic periapical abscess is often the cause of a sinus tract in the gingi- ral trssucs of childrcn. -\ chronic periapical granuloma is the most common sequelae ofpulpitis. It is asymptomatic and asiLrcialed wiih a non-vital tooth. .\ cementoma occurs most frequently in the ant€rior region ofthe mandible. It starts as a radiolucent leritrn and then calcifies. The cementoma does not affect pulp vitality. Also called periapical cemen- tal dlsplasia. .q, traumatic bone cyst is not a truc cyst sincc thcrc is no epithclial lining. Found mostly in young pcople. asymptomatic. Radiolucency which appears to scallop around the roots ofteeth. Teeth are usuallv \itel. A gfobulomaxillary cyst (developmental cys, is found at the junction of the globular and maxillary processcs ofthc maxilla, between thc lateral incisor and the canine roots. Teeth are vital. Alateral periodontal cyst occurs on a lateral periodontal location and it is ofdcvclopmental origin aris- ing fiom cystic degeneration ofclear cells ofthe dental lamina. Tooth is vital. An ameloblastoma is a benign, locally aggressive tumor arising from the odontogenic ectodem.Lesions occur as multilocular radiolucencics and frequently cause extensive root resorption. Thc mandible is affected four times more frequently than the maxilla. A cementoblastoma is an odontogenic tumor characterized by the proliferation offunctional cementoblasts that folm a large mass ofcemennrm or cementum-like tissue on the tooth root.

The ? in the apical portion of the pulp help to form the pulp into semisolid mass fascilitating a ? Collagen, pulpectomy Network of capillaries and nerves, pulpectomy Collagen, pulpotomy Network of capillaries and nerves, pulpotomy

Collagen, pulpectomy Mainly, Type I and Type III collagen is present in the pulp in a ratio of557o : 45%. Type V is found in small amounts. In dentin, Type I collagen predominates. Odontoblasts syn- thesize Type I while fibroblasts in the pulp synthesize both Type I and Il. The central zone or pulp proper contains large nerves and blood vessels. This area is lined peripherally by a specialized odontogenic area which has three layers most to outermosl). l. Cell rich zone: innermost pulp layer which contain fibroblasts. 2. Cell-free zone or zone of Weil: is rich in both capillaries and nerve networks. The nerve plexus ofRaschkow is located here. 3. Odontoblastic layer: outermost pulp Iayer rl,hich contains odonroblasts and lies next to the Dredentin and mature dentin. Cells found in the dental pulp include fibroblasts (the principal cell). odontoblasts, his- trocyles (mocrop haset, and lymphocytes. Note: In a diseased pulp, the following cells are present: PMN's, plasma cells, basophils, eosinophils. lymphocltes, and m ast cells (contain histantine and heparin). Important: The pulp lacks collateral circulation, which severely limits its ability to copc rr ith bacteria. necrotic tissue. and inflammation.

During the master cone fitting procedure in the endodontic treatment of a patients tooth the patient says he has a "sharp shooting pain in the same tooth that ached earlier" . What should your response be and why? Continue with obturation, the anesthetic is simply wearing off Continue with obturation, this is a normal complaint during this part ofthe procedure Consider looking for an accessory canal and re-filing, there is likely pulpal tissue that has not been properly debrided Inigate furtheq the Sodium Hlpochlorite should take care ofthis problem Temoorize the tooth and obturate at a later date

Consider looking for an accessory canal and re-filing, there is likely pulpal tissue that has not been properly debrided This indicates inadequate debridement, as a pulpless tooth should not respond to any stimuli. The most important consideration before filling a root canai is prop€r cleaning (debride- ner, and shaping (instrumentin&) ofthe canal. Once the canal is obturated, any organisms that have entered the periapical tissues from the canal are eliminated by the natunl defenses ofthe body. Objectives of root canal obturation: . . . To develop a fluid-tight seal at the apical foramen Complete filling ofthe root canal space To create a favorable biologic environment for the process oftissue healing ln endodontic treatment the importance ofcanal obturation (/i//,rg) is second only to canal debridement friic h is the ke! to succe$. Approximately 40% offailures are believed to be caused by incomplete obturation ofthe root canal. lfthe canal is not filled, tissue flr,rid and mi- croorganisms from the periapical tissues are able to enter the voids, with failure as the ultimate result. Howeyer, if an accessory canal is not totally filled during obturation, the appropri- ate treatment is to observe the tooth and evaluate every three months. Remember: The presence of a periapical lesion before root canal treatment will reduce the success rate of the treatment by 10%-20%. Note: After endodontic therapy is completed on a tooth with a periapical radiolucency, it nsu- ally takes 6-12 months before marked reduction in the size ofthe radiolucency is evident on an x-ra.v. Desired periapical tissue changes include regenention ofalveolar bone, deposition of aoical cementum. and re-establishment ofthe PDL.

The most superior of all other retrofilling material- mineral trioxide aggregate (MTA) has all of the following advantages except TWO Radiopaque Easy to manipulate Hydrophilic Biocompatible Not toxic Short setting time Induction of hard tissue formation

Easy to manipulate Short setting time The main ions found in MTA are calcium and phosphorus. MTA has a high pH so it induces hard tissue formation. MTA has superior sealing ability and is not adversely affected by biood contaminants. [t also causes only low levels of inflammation because it forms fibrous con- nective tissue and cementum when in contact with the pe odontium. Note: MTA is difficult to manipulate and has a long settilg time. Despite these disadvantages, it's the material of choice today. A retrofif ling falso called a reverse f lling or retrograde qmalgam.filling) rs placed to seal the apical portion ofthe root canal. This procedure is used when an apicoectomv alone will not yield a good result. Whenever there is any chance whatsoever that an apical seal may be faulty, a reverse filling material must be placed. For example, if the root canal appears cal- cified. it would be impossible to obturate most ofthe canal and get a seal. Ifjust the root apex were cut off faplcoectoatl, the incompletely filled canal might act as a source ofreinfection. To prevent this after the root tip is resected, the foramen is found, enlarged, and filled with a zinc-ftee amalgam to create a seal. An apicoectomy ot-end rcsection) is a procedure where the buccal tissue is flapped back, the buccal bone about the apex is removed, the root apex is removed, and the area is curet- lro ted out. Indications for apicoectomy: l) A reverse filling needs to be placed 2) It is neces- sar] ro gain access to an area ofpathosis 3) The poorly filled apical portion ofthe root is to be removed to the level ofcanal obliteration. Note: A retrograde amalgam hlling should al- $ a1s be done after an apicoectomy. Teeth that have posts in them and need to be retreated are rhe most common reason for an apicoectomy and a retrograde filling. Remember: Periapical curettage is the same procedure as an apicoectomy and remotal ofbuccal hor€) but without removing the root apex. Removal and examination ofthe diseased tissue and determination ofthe extent ofthe lesion are the objectives ofapical curet- Iace.

During a radiogrph you notice bone loss extending from the cementoenamel junction to the apex of tooth #21. Probing depths are above normal all around the tooth. However at one point the probe drops to an even greater depth. Vitality test is negative. This patient may require: Extensive periodontal treatment followed by vitality reassessment Endodontic treatment only Endodontic treatment followed by periodontic treatment Root end surgery Periodontic treatment followed by endodontic treatment

Endodontic treatment followed by periodontic treatment In a combined perio-endo lesion, endodontic treatment generally takes precedence over periodontal management. Combined endodontic-periodontal therapy is widely used because the anatomic and clinical connections between the pulp and periodontal structures are close and numerous. In most cases ofthis nature, endodontic procedures are preformed first and, when nec- essary, are followed by periodontal measures. In these cases, the value ofprecise pocket probing and correct appraisal olthe vitality of the pulp is crucial. In some doubtful cases, the better part of wisdom is to wait until after the completion ol the root canal therapy to see whether spontaneous resolution lpocket closure and osseous begun. ./ill-in) will occur before surgical periodontal procedures are Periodontal therapy should be initiated first only in the case ofa primary periodontal lesion rvith subsequent secondary endodontic involvement. Remember: A common clinical finding ofa periodontal problem is pain to lateral per- cussion on a tooth with a wide sulcular pocket. Note: The combination lesion (perio-endo) bacteria

You are retreating a previous RCT, which one of the following is least likely to be used? Rotary files Chloroform Glass bead sterilizer Ultrasonic Heated instruments

Glass bead sterilizer Techniques to remove gutta-percha include: . . . . . Rotary removal Ultrasonic removal Heat removal Heat and instrument removal File and chemical removal Chloroform is the reagent of choice to dissolve gutta-percha. [t is very effective but should be used with caution. Its vapor is potentially hazardous, so it is dripped directly in the canal avoiding excessive flooding. Other chemicals which can dissolve gutta-percha to a varying degree include: xylol, halothane, benzene, carbon disulfide, essential oils, rrethyl chloroform and white rectified turpentine. If a gutta-percha cone has passed beyond the ap€x then a file must be used beyond the apex in order to avoid breakage ofthe cone. A broken cone in the periapical area may re- sult in an orthograde re-treatment lailure. ,'Notes, *** l. Gutta-percha points may be disinfected by placing them in a 5.25% NaOCI solution for one minute. 2. A glass bead sterilizer can sterilize endodontic files in l5 seconds at 220' c u2n F).

A patient presents with an acute periapical process. Which of the following tests could have a positive response? EPT Cold test Heat test

Heat test The tooth will not respond to the EPT or cold tests but may respond to heat Ofall the denral abscesses. the periapical is the most common It is a localized colleclion ofpus in thc alveolar bone at the root apex following death ofthe pulp with extension ofthe infection into the periapical t?e. tissue. The first symptom may be a slight tendemess ofth(r tooth. This later develops into a severe throbbing pair. (ac te abscess) with swelling ofthe overlying mucosa. Reducing thc irrilant, reduction ofprcssurc. or thc removal ofthe inflamed pulp is the immediate goal. Ofthese, pressure relcase is the most effective in re- lie\ ing the patient's pain. Emergency treatment includes establishingdqinage (ideall! throlryh the cana[) and prescribing antibiotics lonlv il indicated hv s)'stemic signs dnd elewted tenlrera ture !\ ill relie\ e ihe acute symptoms followed by conventional endodonric thcrapy at a latcr datc. Note: Complete cleaning and shaping ofthe root canals is the preferred treatment. Horvever, iffor some reason this is not :ible. a pulporomv is usually effective in the absence ofpcrcussion sensitivity. Important:\\hen diffuse swelling exists, the swelling has disscctcd into fascial spaccs. The most important objecti\ e is the removal ofthe irritant via canal debridement or extraction ofthe offcnding tooth. Swclling may be incised and drained followed by drain insenion and systcmic antibiotics. \ote: For endodontic infections that do not respond to "moth- ) and ni alges ics. This penicillin VK, clindamycin is olien recommended. It produces high blood levels and is eflective against anaerobic bacteria but must be used with caution bccause of the polenlral for p.cudomembranou. colrtis. - l. A history ofpre-opcrative pain and s*'eiling is the best predictor of interappointment cmcr- :Nol3*' ,- ' gencres. 2. No relationship exists between flare-ups and treatment procedures /i.e.. rirgle ormultiple|is- 3. The periodontal abscess is an acute abscess lhat devclops through thc periodontal pocket. Alve- olar bone loss, pocket formation and pe odontal pathologic conditions are suggestive ofthe peri- odontal abscess. The tooth \rill usually be palpation and percussion positive. lt will respond to the electric pulp tester frrlike the periapical abscert. Bact€ria associated with this abscess include gftm-negative rods sucb as Capnocytophaga species, Vibrio-corroding organisms and Fusobac- lenum spccles, 4. The gingival absc€ss is a relative rarity rhat occurs wh€n the bacteria iDvade through some break in th€ gingival surface. Such abrasions may be the result ofmastication, oral hygien€ pro- ccdurcs. or dcntal trcalmcnt.

? most often refer pain to the temporal region, while ? most often refer pain ot the ear. Maxillary second premolars, mandibular molars Maxillary molars, mandibular molars Maxillary second premolars, mandibular premolars . Maxillary molars, mandibular premolars

Maxillary second premolars, mandibular molars fcaref'ul diagnosis does not reveal the afl'ected tooth, other teeth and related anatomic structures become suspect. Pulpitis in one tooth may cause pain in other areas ferred. Important: The nerve endings of cranial neryes Vll, lX, and X are widely distributed within the subnucleus caudalis ofthe trigeminal - the pain is re- (V) newe. A profuse intenningling ofthese nerve fibers creates the potential fbr the referral ofdental pain to many sites. Orofacial pain can be the clinical manifestation of a variety of diseases involving the head and neck region. The cause ofthe pain must be differentiated between odontogenic and nonodontogenic. Characteristics of nonodontogenic involvement: . . . . . . Fpi:udrc pain with pain free remissions Tdgger points Pain travels and crosses the midline ofthe face Pain that surfaces with increasinq stress Pain that is seasonal ar cyclic Pain accompanied by paresthesia

The external resorption in which in an infected pulp may further complicate the resorptive process is called Surface resorption Inflammatory resorption Replacement resorption

Inflammatory resorption Bowl-shaped areas ofresorption involving cementum and dentin characterize external inllammatory root resorption. This type ofresorption is rapidly progressive and will continue iftreatment is not insti- tuted. Since both a necrotic pulp and the presence ofbacteda are necessary components ofinflammatory rcsorption, the process can be arrested by jmmediate root canal beatment. The tooth is opened and the canal is cleaned and shaped. A calcium hydroxide paste is placed in the canal. This is replaced every three months for one year If after one year, it appears that the resorption has stopped, a c nal filling (gutta-percia) can be placed. A calcium hydroxide-based root canal sealer is strongly recommended. Surface resorption is caused by acute injury to the periodontal ligament and root sulface. It is very common, self-limiting, and reversible. Ifinjury is not repeated, healing takes place with new cementum and PDL. Root surface resorption is limited to cementum, may heal itself, and is not radiographically vis- ible. Replacement resorption refers to resorption ofthe root surface and its substitution by bone, resulting in ankylosis. Replacement absorption accompanies dentoalveolar ankylosis due to extensive hauma to the tooths aftachment ^ppafifis (peliodontal permanent root ligament damage).The tooth is often in infraocclusion due to progressive submergence with growth. There is a metallic sound on percussion. Rememberi This is often seen in unsuccessful replant cases. Remember the etiology ofextemal and intemal resorption: . Erternaf resorption: periradicular inflammation, dental trauma (/erultihg in dafiage b attachhent apparatut), excessive orthodontic forces, impacted teeth, intemal bleaching ofnon-vital teeth. . Internal resorption: dental trauma (resulting in loss of vitalit)' and subsequent i fection), caries, pulp capping with calcium hydroxide, cracked tooth. Note: Invasive cervical resorption is a clinical term used to describe a relatively uncommon, insidious and often aggressive form ofextemal tooth resorption. Cha.acterized by its cervical location and inva- sive nature, this resorptive process leads to progressive and usually destructive loss oftooth structure. Resorption of coronal dentin and enamel often creates a clinically obvious pinkish color in the tooth crown as highly vascular resorptive tissue becomes visible through thin residual enamel. ImportantiThe majority ofmisdiagnoses ofresorptive defects are made between intemal root resorptions. cervical caries. and cervical resomtion.

All of the following statements regarding adjuncts to endodontic treatment are true EXCEPT Transplanted teeth with partial root development have a better prognosis than those with developed roots . Orthodontic extrusion is a common indication prior to implant placement Intentional replantation is a viable altemative to endodontic surgery A major disadvantage of endodontic implants is the lack of an apical seal

Intentional replantation is a viable altemative to endodontic surgery Intentional replantation is not a substitute for endodontic surgery if it can be undertaken. Transplantation is the transfer ofa tooth from one alveolar socket to another either in the same person or in another person. Orthodontic extrusion is defined as force-controlled vertical tooth movement occlusally in the socket. Indications include untreatable subgingival pathoses e.9., cervical caries, cer- vical fracture, periodontal defects, resorptive lesions and perforations in the cervical atea. Crown lengthening is a procedure used to apically position the gingival margin and./or to reduce the cervical bone. It is employed during the treatment of subgingival caries, perforations and resorption. Root submersion involves resection of tooth roots 3 mm below the alveolar crest. The coronal portion ofthe tooth is removed and the roots are covered with a mucoperiosteal flap. Indications include rampant caries, adverse periodontal conditions and in cases that have had repeated prosthetic failures. The submerged roots will prevent alveolar resorp- tion and maintain better proprioception. This is especially useful in medically compromised or handicapped patients requiring better denture control- Sometimes, this is also done to avoid formation of an esthetic defect that may result after extraction.

Which condition has pain thats spontaneous and has periods of cessation (intermittent in nature) Reversible pulpitis Irreversible pulpitis

Irreversible pulpitis The severity ofthe clinical symptoms will vary as the inflammatory response increases. Pain $ ill vary liom a mild and readily tolerated discomfort to a severe, throbbing and excruciating pain. The pain is spontaneous! unprovoked! and is int€rmittent or continuous in naturc. Thc pain lingers after the removal ofthe irritant. but is difuse in character Lying down or bcnding over intensifies the pain The pain is usually not readily localized by the patient ofineversible pulpitis because the overall increase in cephalic blood pressure is relayed to thc confined pulp tissue. The tooth may be tenderto percussion, heat may intensit the pain response while cold m y relieve it (in ad|anced s/dgerl. Usually they both will cause severe and lasring pain. Thc radiographs will usually disclose no periapical patholog!. Treatment is root canaltherapy. Note: In cases ofirrev€rsible pulpitis, an acutcly inflamed pulp is symptomatic whercas a chronically inflnmed pulp is rs) mptomatic in most cases. The end result is necrosis ofthe pulp. . Asymptomatic irreversible pulpitis- possible consequences: - Hyperplastic pulpitis: a rcddish, cauliflower-like growrh ofpulp tissue through and around a carious exposure ofa grossly decayed tooth. -Internal resorptioni is a pathological process initiated *,ithin the pulp space uith the loss ofdentin. k often is described as an oval-shaped enlargement ofthe root canal space and usually is asymptomatic and detectable by routine radioSraphs. . Sr"mptomatic irrerersible pulpitis: as dcscribcd above, the pain is spontrneous, unprovoked! and is in- termitt€nt or continuous in nature- Pain will vary liom a mild and readily tolerared discomfoft to a severe, throbbing and excruciating pain. Relersible pulpitis /h\'percniaI the pain associated with hlperemia does not occur spontaneously. I1 requires an extemal irritant to evoke a painful response /i.{,., .o/d. srt?ctr). Thc pains are sharp and ofbrief du- ration. ceasing \\'hen the irrilant is removed. Radiographs appear normtl lnat'shov,deep caries or catiq /,r1'l,1,"drirr. The tooth is usuirlly percussion negativc. In thcrmal tests. the pulp rcsponds more readily to cold itrmuli fian to hot 1t € respo se laaws shortlv after rcnotal olthe stirrrlfur). Treatment usually is a seda- tire filling or nell restoration lvith a base. Caus.\ ofrel ersible pulpitis inchde early carics, p€riodonl1l scaling, root planing. microleakage, and restora- ronj placcd $ithout a base. Remember: Reversible pulpitis is not a diseasc, rather it is a symptom. Ifthe ir- ritanl ii removed, the pulp will revert to a healthy slatc. If the irritant rcmains, the symptoms may lead to irre|ersiblc pulpi!is. \otei Pulpaf intlrmm^tion (h.r'perenia) is most commonly caused by bacteria.

All of the following statements regarding EDTA are true except It is a chelating agent with the capability to remove the mineralized portion ofthe smear layer It can decalcify up to a 50 um thin layer ofthe root canal wall Normally it is used in a concentration of l7% RC-Prep and EDTAC are other preparations of EDTA The decalcifying process induced by EDTA is selfJimiting It is also an excellent irrigation solution

It is also an excellent irrigation solution This is false; it has a limited value as irrigation solution. The decalcifying process in- duced by EDTA is selfJimiting and stops as soon as the chelator is used up. Chelating agents are used to aid and simplify preparation for very sclerotic canals after the apex has already been reached with a fine instrument. These agents act on calcified tissues only and have little effect on periapical tissue. Their action is to substitute sodium ions, which combine with the dentin to give soluble salts for the calcium ions that are bound in less soluble combination. The edges of the canal are thus softer, and canal en- largement is facilitated. EDTA will remain active in the canal for 5 days if not inactivated. For this reason, at the completion ofthe appointment the canal must be irrigated with a sodium hypochlorite containing solution. Note: Rinsing for I minute with EDTA eliminates the smear laver, opens dentinal tubules, and provides a cleaner surface for gutta-percha (NTOCl) and sealer to adapt. EDTAC is EDTA with the addition of Cetavlon, a quatemary ammonium compound. lt has greater antimicrobial action than EDTA. However, it has greater inflammatory po- tential to tissue as well. The inactivator for EDTAC is NaOCl. RC-PREP combines the functions ofEDTA plus urea peroxide to provide both chela- tion and irrigation. The foamy solution has a natural effervescence that is increased by ir- rigation with NaOCI to aid in the removal oldebris.

The major advantage of zinc oxide eugenol based sealer types Non-staining property Fast setting time Adhesion lnsolubility Long history of successful usage

Long history of successful usage Remember: The primary function ofa root canal sealer is to fill in the discrepancies between the core-filling material and the dentin wall. In fact it is said that it is more important than the core filling material. Other purposes or functions ola root canal scalcr includc: . To act as a lubricant, facilitating placement ofthc gutta-pcrcha . . To form a bond between the filling material and the dentin walls To exert antibacterial activity (some exert more than others). This activity is the highest in the period of time immediately aft€r its placement. Most root canal scalers are some type ofzinc oxide-eugenol cement and are capablc of producing a seal whilc bcing well-tolerated by periapical tissues. All sealers display some degree of radiopacity (caused by metollic sahs in the sealer); thus are visiblc on a radiograph. This helps disclose the presence of accessory canals, re- sorptivc arcas, root fracturcs, and thc shapc ofthc apical foramen and other structurcs of lnterest. Note: After filling a tooth with gutta-percha, if you see a horizontal line of firaterial (gutta-percha or sealer) extending both mesially and distally from thc canal to thc pcriodontal ligament space, this is indicative of a root fracture. ZOE disadvantages: staining, slow setting time, non-adhesion, solubility.

The main benefit of primary incisor replantation is Maintenance of a normal anterior dentition To relieve parental guilt To maintain child's self-esteem To maintain child's social acceptance

Maintenance of a normal anterior dentition The question ofwhether to replant primary teeth has been a focus of debate and contro- versy in the dental literaturc. However, most dental textbooks uniformly recommend that pri- mary teeth not be replanted. Replantation ofa primary tooth is not recommended because of the potential danger to the permanent successor from sequels of trauma losis, or damage dtrc to uqnipulqtion during procedure itselfl. fe.&, infection, anlg Proper management of an avulsed permanent tooth that has been replanted within two hours ofthe accident: . Ten days to two weeks after replantation, the rcot canal is preparcd (cleaned qnd.\hqped) and a calcium hydroxide paste is placed into the canals . . This paste is r€placed every three months for one year Ifafter one year, it appears that resorption has reversed or stopped, a permanent gutta-percha filling can be placed lmportant: Ifa tooth is out ofthe mouth for more than two hours: . Ank)"losis and external root resorption will probably result within two years. Ankylo- sis resulting from replacement would give a better prognosis than external resorption, u hich rvill lead to failure. . . Root canal therapy is performed in its entirety prior to replantation. The tooth is soaked in a 2.47o fluoride solution acidulated at pH 5.5 for 20 minutes or more. The 0uoride will slow the resorptive process. . . Gently curette blood clot out ofthe alveolar socket and irrigate with saline. Rinse tooth with saline, replant into socket, and splint for a maximum of2 weeks. Note: Resorption is the most frequent sequela to replantation. Three different types of re- (qnlg'lotic resorption). Replacement resorption refers to resorption ofthe roat surface and its substitution by bone, sorption have been identified: surface, inllammatory and replacement resulting in ankylosis.

? require endodontic treatment more than any other tooth, while ? have the highest endodontic failure rate Mandibular first molars, maxillary first molars Mandibular first molars, maxillary second molars . Maxillary second molars, mandibular first molars Maxillary first molars, mandibular first molars

Mandibular first molars, maxillary first molars Mandibular molars are characterized by a trapezoidal outline of the pulp chamber. This outline is formed by two canals in the mesial root and one oval canal in the distal root. ln approximately 287o (offrst molars) ofthe cases the distal root may have a second canal (burth canal overal1). The pulp chamber is located in the mesial two-thirds olthe crown. Important: You must look for the fourth canal ifthe first-found canal in the distal root lies more toward the buccal, instead ofbeing located in the center I . The lingual wall ofmandibular teeth is most easily perforated when prepar- ing an access opening due to the lingual inclination ofthese teeth. 2. The mandibular first molar requires endodontic treatment more frequently than any other tooth in the oral cavity. Maxillary molars have a triangle outline of the chamber: . . . The base of it is formed by the buccal canals, the apex by tlte palatal canal The line connecting the mesial with the palatal canal is the longest Ifa fourth canal is present, it is usually located lingual to the orifice ofthe mesiobuc- cal canal. and in the mesiobuccal root. lt is much more common than previously thought. .: . ,. /l\odr .a4,^ 1. The mesiobuccal of the maxitlary molars is the most complex root in the entire dentition because 90o% have either second canals or major fins leading off of the mesiobuccal cana.. 2. The maxillary first molar is the posterior tooth with the highest endodon- tic failure rate. The lingual or palatal root is the longest, has the largest diam- eter, and offers the easiest access. The clinician should always assume there are two canals in the mesiobuccal root until it is proven there is only one.

Which tooth has a pulp chamber that is least like the others Maxillary central incisor Mandibular central incisor Maxillary lateral incisor Mandibular lateral incisor

Maxillary central incisor The base ofthe triangle lvill be the f'acial. The apex will be the lingual. llit is not triangular, then rtwill be oval, Over 607o olmaxillary ccntril incisors show accessory canals, and thc apical foramen is found apa11 flonr the apex in .157o of$ese tecth. ldeal access preparation ofnlaxillary central incisors is ovxl-triangulrr on rhe lingual surface oflhe tooth \\'ilh a sli!ht cune lingually to avoid reducing the incisal edge. The cenical cross sections below olthe maxillar] permanent teeth sho\r the relationship ofthe crown outline to the pulp chamber and the root canal.

Which of the following is most likely to have a curved root Maxillary central incisor Maxillary lateral incisor Maxillary canine Mandibular central incisor

Maxillary lateral incisor The maxiiJary lateral incisor ahvays h{s one root with one canal. The root is more slender than in the maxillary central incisorand frequently The access opening is oval. f99.9Zo) 1557,y' has a distal and/or lingual curvature or dilaceration. Maxillary central incisor: The maxillary central incisor always has one root and one canal. The root is bulky, with a slight distal axial inclination but rarely has a dilaccration. The access opening is oval- triartgular. Maxillary canine: The maxillary canine always has one root and one canal. This tooth is the longest in the arch. The access opening is o\al. Note: The maxillary central, lateral, and caninc roots and hence, canals all have a distal axial inclina- tion. This mcans in pcnetrating along thc long axjs ofthe tooth, the bur must be slightly angled toward the distal surface. Failure to do this may lead to perforation ofthe mesial portion ofthe root. Remember: The mandibular incisors (latemls and centrals) ha're only one root which is narrow mesjodistally but relatively wide labiolingually and may have a distal and/or lingual curvature. Two canals may be present. When there are two canals, the labial canal is the straighter one. The access opening for a orandibular central or lateral is a long oval, with the greatest width placed incisogingivally and the incisal extent very close to the incisal edge. Perforation: Although many errors can potentially occur during acccss preparations, the most deictcri- ous is perforation ofthe pulp chamber space into the oral cavify or periodontal tissues. Ifthe perforation occurs above the osseous crest in the gingival sulcus or above the free gingival margin, consider the following measures: (l) Control hemorrhage with a dry cotton pellet or some hemostatic agent, do not use formocrcosol (2) Scalwidl a temporary cement, such as Cavit orZOE, (3) Procccd with RCT (4) Plan to restore perforated area separately or make such restoration part of the final tooth preparation. Ifthe pedoration is at or below the osseous crest or into the furcation region, thc following steps can bc considered; horvever, the prognosis for thcse cases is very poor (l) Seal the perforation immediately (2) If the pcrforation is close to a canal orifice, place a file, gutta-percha cone! or silver cone into thc canal to prcvcnt the placement ofmaterial in the canal during the repair (3) Control the hemorrhage, if it can not be controlled due to size the[ use a pulp capping agcnt, such as Dycal, if it is controllable, use Cavit or ZOE to seal perforation (4) Try to avoid pushing any sealing materials into the periradicular tissues.

Which of the following is improperly matched with the reason for difficulty of its access preparation? Maxillary first premolar - mesial concavity Maxillary molar - proximity of canals to mesio-buccal line angle Mandibular molar - mesiolingual tilt of tooth Mandibular incisor - small buccal-lingual dimension

Maxillary molar - proximity of canals to mesio-buccal line angle Major objectives ofthe access preparation: l. StraighGline access 2. Conservation of tooth structur€ 3. Unroofing ofthe chamber and to remove pulp horns Access to the root canal is the initial step in canal preparation. It is necessary to estab- Iish straight-line access to the apical foramen to ensure free movement ofthe instrument during debridement and preparation ofthe canal. A1l the treatment that follows hinges on the correctness ofthe access preparation. All access cavities are made through the lingual on anterior teeth and through the occlusal on posterior teeth. Note: A facial approach is recommended for an access opening on maxillary primary incisors. Remember: Mandibular incisors and maxillary first premolars require the most care to avoid perforation during preparation ofthe access opening. This is due to the narrow mesio-distal dimension ofthe rnandibular incisors and the mesial concavitv ofthe max- illary first premolars. Important: During access preparation on mandibular molars, lhe following two regions tend to be "overcut" which results in the undesirable over preparation ofthe tooth: . . The mesial aspect under the marginal ridge The lingual surface under the lingual cusps *** Mandibular molars tip mesially and lingually. Ifa bur is directed straight inferior it may cause unnecessary loss oftooth structure ftom the these areas.

The main concept of the coneshift technique is that as the vertical or horizontal angulalations of the xray tube head changes the object buccal or closest to the tube head moves to the ? side of the radiograph when compared to the lingual object Same Opposite

Opposite n other words, wc can say that the cone image shift technique separates and idenlifies thc facial and lingual structures. Noter The cone shif-t technique is also known as thc buccal object rule, SLOB rufe (Saae Lhgual, Opposite Buccaf, Clark's rule or Walton's Projection. As the conc position moves lrom parallel either towards horizonlal or vertical, the objcct on the film shifts away from the dircction ofthc cone (i.e., in the direction ol the central beatt). Note: ln order to apply this rule, you must have a reference object. Important: A disadvantage of the cone shili technique is that it results in blurring of the object uhich is directly proportional to cone angle. The clearest radiograph is achieved by thc paralleling tcchnique so when thc central beam changes direction rclativc to thc object and the film, the ob- ject becones blurry. \\'hen trearing multicanaled bicuspids and molars. it is ol'ten difficult to ascertain on the radiograph $hich canal is more toward thc buccal. When a straight-on exposure is taken ofa bi- canaled tooth. thc canals become supe mposed on the filnl, and visualization of each canal is im- possible. Ifthe x-ray cone is moved to give an angled exposure, the roots will bc separate on the film. By'applying the cone image technique you will be able to determine which canal is thc buccal and rvhich is the lingual. Explanation of SLOB (Same Lingual, Opposite Buccal) rule; the object toward the lingual will appear to shift on the film to the same direction as the repositioned x-ray cone. For example, ifthe x-ray cone is mesially angulated, the lingual/palatal ob- side (closer to the ject (root) liln) will shilt toward the same (nesiql) side in the resultant radiograph film, and thus will be easily visualized. Note: Uring this technique you can determine: l Working length of superimposed canals. 2. Curvatures of root/canals. 3. Facial-Lingual orientation ofinstrum€nts, or other anatomical objects.

THE FIRST FEW PAGES ASK TO IMAGINE THE ACCESS PREPARATIONS FOR DIFFERENT TEETH MAKE SURE TO TAKE A LOOK

PAGES 1-7

While doing a vital pulpotomy on a young immature permanent tooth, the hemmorrhage after pulp amputation could not be controlled with cotton pellets even after several minutes. Whats the next step in completing this treatment? Control the hemorrhage with hemostatic agents Apply formocresol with cotton pellets at the amputation site Irrigate the canal with sodium hypochlorite then apply calcium hydroxide Perform the amputation at a more apical level Stop the procedure and close the tooth with an interim restoration All of the above

Perform the amputation at a more apical level Uncontrolled bleeding is a sign ofinflamed pulp tissue. The radicular pulp must be uninflamed for the success ofthis procedure. It is not uncommon to find uninflamed pulp at a more apical level, especially in cariously exposed teeth. If bleeding does not stop even after more apical amputation, hemostatic agents are used as a compromise treatment. These are closely monitored and if vitality is lost, apexificatiorr (pulpectomy) procedures should be instituted. Pulpotomy is the surgical removal of the coronal portion of a vital pulp to preserve the vitality ofthe remaining radicular pulp. The common indications include: . Cariously exposed deciduous te€th -with healthy radicular pulps . Traumatic or carious exposure ofpermanent teeth with undeveloped roots . . An alternative to extraclion when endodontic treatment is not available Emerg€ncy treatment in permanent teeth with acute pulpitis Unfortunately, pulpotomy procedures performed in fully developed permanent teeth are not found to be successful. For this reason it is regarded as a temporary procedure in these teeth.

Which of the following is not a key feature of replacement resorption Lack of mobility Lack of PDL on x-ray Pink Appearance Infra-occlusion

Pink Appearance Traditionally pink tooth has been considered pathognomonic ofinternal resorption and is sometimes a feature ofcervical root resorption. lt is characterized by a pinkish ap- pearance of the tooth due to the grofih of granulation tissue undermining the coronal dentin. Replacement resorption, which accompanies dentoalveolar ankylosis resulting from ex- tensive trauma to the attachment apparatus ofthe tooth is characterized by progressive re- placement ofthe root by the bone. Note: Histologically, it shows direct contact befween dentin and bone with no intervening PDL or cemental layer. Remember: Replacement resorption's pathognomonic signs are: 1. Lack of mobility 2. Metallic sound to percussion 3. lnfra-occlusion of the involved tooth in the developing dentition Important: Tooth mobility is directly proportional to the integrity of the attachment apparatus or to the extent of inflammation of the PDL. Other causes oftooth mobility in- c Iude: . . . . Horizontal root fracture Recent trauma Bruxism Ovezealous orthodontic treatment

Which cells do not characterize the cellular response Plasmamcells Macrophages Lymphocyes Polymorphonuclear (PMN) Leukocytes

Polymorphonuclear (PMN) Leukocytes The onset ofpulpal inflammation is an insidious process and is characterized by a chronic cel- fufar response fplasmq (or cells, macrophages and l,vmphoq'tes). There is no direct exposure of the pulp to dental caries and the response, therefbre, is not acute. After pulp exposure, the acute inflammatory cells (nainly PMN celA, are chemotactically attracted to the area. Histo- logicalh, the tissue is likely to show signs ofacute inflammation near the site ofthe exposure and a band ofchronic inflammatory cells between the acute inflammation and the underlying normal pulp. The response ofvital pulp to microbial invasion is very resistant. Based on the observation IhaI e\ en alier t$,o weeks of tmumatic pulp exposure, only 2 mm of coronal pulp may "give in" to microorganisms. Non-yital pulp, in contrast, is a "fertile ground" for the growth of mi- croorganisms. Remember: Carious exposures in permanent teeth generally require root canal treatment. Im- matld(e (open qper) or pulpotomv procedures. pennanent teeth with carious exposures can be treated by pulp capping Important: Pulp capping is not recommended in primary teeth with carious exposures due to its high failure rate and because pulpotomy, having similar time requirements. has shown to be very successful. Pulp capping can be done, however, in mechanical exposures. 1. Calcium hydroxide has a high pH of 12.5 which cauterizes tissue and causes superficial necrosis. 2. This necrotic zone encourages the pulp to induce hard tissue repair with sec- ondary odontoblasts laying down reparative dentin.

Which two bacteria below are the most commonly found bacteria in endodontic infections Porphyromonas species and Bacteroides melaninogenica Eubacterium and Fusobacterium Actinomycetes and Spirochetes Wolinella and Veillonella species

Porphyromonas species and Bacteroides melaninogenica Predominant bacterial species isolated from infected root canals include: . . . . . . Porphyromonas species Bacteroides melaninogenica Eubacterium species Peptostreptococcus species Fusobacterium species Prevotella species *** Note: Strict anearobes predominate Virulence factors which play a role in periradicular pathosis include: . . . Lipopolysaccharide (LPS): found on the surface ofgram negative bacteria Enzymes: neutralize antibodies and complenent components Extracellular vesicles: involved in bacterial adhesion, proteolytic activities, hemag- glutination and hemolysis . Fatty acids: affect chemotaxis and phagocytosis A vital pulp resists bacterial invasion. Even ifthe pulp is exposed to microorganisns for 2 weeks, the penetration ofbacteria may extend no more than 2 mm into the pulp. In contrast, a non-vital pulp is a fertile ground for the growth of microorganisms and leads to necrosis. Remember: Streptococcus species may be more important in the initiation ofrather than the progress of a carious lesion leading to a pulp exposure. Strict anaerobes are found to play a significant role in periapical pathoses.

The abscence of which layer of dentin predisposes it to internal resorption by cells present in the pulp Mantle dentin Circumpulpal dentin Predentin Secondary dentin Tertiary dentin

Predentin Immediately adjacent to the odontoblast layer in the pulp, l0-47 pm ofthe dentin matrix remain unmineralized. Ifthis unmineralized layer ofdentin is lost infectious process) it predisposes the dentin to internal resorption by odontoclasts. . 1e.g., Mantle dentin: is first-formed dentin which is laid before odontoblast layer gets organized. Hence the pattern ofdeposition and size ofcollagen fibers is different from cjrcumpulpal dentin. . . Circumpulpal dentin: represents most of the dentin which is formed. Secondary dentin lorms after eruption of a tooth and throughout life resulting in a Sradual . but asymmetric reduction in pulp size. Tertiary dentin or reparative dentin: is an irregular and disorganized layer ofdentin laid dorvn in response to any injurious/irritant stimuli. Note: Dentin lormation is the primary function ofpulp. Other functions include: . Induction: forms dentin which in turn induces enamel formation . i Nutrition: dentinal tubules are linked to the pulp which maintains its hydration and formation of peritubular dentin .. .. l. Once bacteria enter the pulp with sufficient quantity or virulence, complete ,/Noq: pulpal necrosis is imminent and ireversible. ?&i Z. Bacteria from dental caries are the main cause of more serious pulpal injury, and the main cause ofpulpitis.

Which of the following are not found in the pulp Reticulin fibers Collagen fibers Unmyelinated nerve fibers Myelinated nerve fibers Proprioceptor nerve fibers

Proprioceptor nerve fibers *** Proprioceptors : trote*: fwhich respond to stimuli regarding mot'ement, are not found in the pulp. The pulp contains both myelinated and unmyelinated nerve fibers. They are afferent and sympathetic. The myelinated fibers are sensory and the unmyelinated fibers are motor ulation ofthe lumen size ofthe blood vessels. -they play a role in the reg- Important: The only type ofnerve ending found in the pulp is the free nerve ending, which is a spe- cific rcceptor for pain. Regardless ofthe sourcc of stimulation fl,eat, will be pain. Afferent N€rve Fibers found in the Dental Pulp: . cold, pressurc), the onl,v rerponse Large myelinated A-delta tibers: enter at tl')e apical foramcn, follow thc path ofthe blood vessels, and then branch to form tl,c Plexus ofRaschkorv beneath the cell rich zone. Within thc plexus, the fibers lose their myclin shcath and proceed to the cell-free zone where they form a subodontoblastic plexus. The free ne e endings then pass into thc odontoblastic layer and the predentin. A-delta fiber pain is immediately pcrceived as a quick, shar?, momcntary pain that dissipatcs quickly on removal ofthe stimulus. Note: The intimate association ofA-delta fibers with thc odontoblastic ccll layer and dentin is rcfcned to as thc pulpo-dentinal complex. . Small unmyelinated C fibers: enter at the apical foramen within thc A dclta fibcr bundlcs; distrib- uted throughout the pulp. They are associated with burning, aching, throbbing q?cs ofpain. Charac- terized by having a high threshold of stimulation. These fibers are true nociceptive fibers pain-conducting fibers that respond to stimuli capable of injuring tissuc. They rcmain cx- cilable even in necrotic tissue. Nole: These fibers are stimulated by hot liquids or foods. Important: When C fiber pain dominates, it significs irreversible local tissue damage. i. As the pulp ages there is a decrease in rettc.ulin f$ers more fibrous). (the pulp becomes less cellular and 2. The sizc ofthe pulp also decreases because ofthe conrinued deposition ofdentin. 3. As thc pulp ages thcrc is an increase in the number ofcollagen fibers and calcifications within the pulp (ca11ed denticles or pulp stones). 4. Pulp stones are associated with chronic pulpal discasc - tiom advanccd carious Icsions or larce restorations.

While cleaning and shaping the canal, an instrument seperates in the canal. As you attempt to retrieve it, the broken instrument passes partially through the apex, thus partly protruding into the periapical lesion. How do you manage this case? Use a smaller H file to bypass it and try retrieving it Use Gates Glidden drills to widen the canal and then try retrieving it Raise a flap and remove the instrument surgically followed by gutta-percha filling the canal Extract the tooth as irreparable damage has occurred to the apex Just inform the patient, fill the canal with gutta-percha and monitor

Raise a flap and remove the instrument surgically followed by gutta-percha filling the canal Cenerally, when a broken instrument protrudes past the apex, surgery should be performed. This constant iritant must be removed. Note: It is relatively easier to retrieve an instrument if it is wedged coronal to the curvature or at the curvature ofthe canal but verv difficult if it has Dassed the curvature. When an instrument breaks off anrvhere in the canal and a periapical radiolucency is present and rninimal canal enlargement has been performed before the accident, surgery is indicated since the periapical tissues have had little opportunity for h€aling to be stimulated. You would prepare and obturate to the point of blockage and then perform an apicoectomy and retrofilling. However, rvhen an instrument is broken off in the apical third and is lodged tightly with no periapical radiolucency evident, the remaining root canal space can be filled. The patient should be informed ofthis and placed on a 3-6 month recall. Important: Prognosis ofa tooth with a broken instrument is best if the tooth had a vital pulp and no periapical lesion.

The earliest and most common symptom associated with an inflamed pulp is A dull thobbing pain on masticatlon Sensitivity to hot, and/or cold stimuli A persistent feeling of discomfort Mild bleeding Pain on percussion

Sensitivity to hot, and/or cold stimuli Thermal sensitivity is thc earliest and most common symptom ofan inflamcd pulp. As caries entcrs thc dcntin it bcgins with a lateral sprcad al thc DEJ. This is duc 1o thc incrcascd orSanic conlcnt and the involvcmcnt ofmany dcntinal tubulcs. Thc Tomcs fibcrs rcact, causirg fa(y dcgencnttion, thcn latcr dccalcifica- /.!.'/.,forrt. As caries progrcsses. destruction ofdentin is followcd by rhc bactcrial invasion ofrhe hrbules and com plclc destruction ofdcntin. Once odontoblasts arc involvcd, pulpal changcs occur. Initially thcrc is vascrlar dilation tion and local cdcma. Tlc carliesa common slmptom ofthis edema fz./rreprlrth.) (as far os is thcrmrl sensitivity (us o?used and persistent puin on upplirution oJ rcld). Rememberr Thc only rcliablc clinical cvidcncc thal sccondary dcntin has formcd is decreased tooth sensitivitl_ tuvnllr seen a is ins.nsitivc \trtes lev vteel.s dlter place e t oIa li ing. whcn dcntinal tubulcs bccomc complctcly calcifrcd. thc dcntin L Thcrmal tcsts arc cspccially valuablcwhcn thc paticnt dcsc.ibcs fic pain fap ullr it1- as dillusc. Thc cold test can bc Lionc w irh cold r s ter bal h s, sticks of icc, €thyl ch loridc, dich lorod ifluo rcnerharc / DDM , Eh.lo k e :. Thc heat test can bc donc wilh wann slicks oflutla pcrcha, using a rubbcr whecl mountcd on a mandrcl revolving at a polishing speed io gcncratc hcat, or a hot rvatcr bath. 3. Thc bcst mclhod to clicit a most sccurute thcrmal rcsponsc is to individually isolatc thc suspcctcd tccth \r'ith a rubbcr dam and thcn balhc cach toolh in hol or cold water This is donc bccausc all other mcthods mav stinulate the iooth at only onc scction ofonc surfacc. ,1. ResDonses to thermal tests: . . \o response: indicates a nonvital pulp or a false negative responsc Mild-fo-mode.ate response: slight pain that subsides within I to 2 scconds; }1ithin nor- mal limits . Strong, momentaay painful response: subsidcs within I to 2 scconds; indicates reversible pulpitis . Moderate-to-strong painful response: lingers for scvcral scconds or longer; indicalcs ir- reversible pulpitis Thermal tcsls may be falsc-ncgativc in immature, recently traumatized lccth or bccausc ofpre- mcdicstion with an analgcsic. 5. Although the percussion test docs not indicatc thc hcalth oflhe pulp, thc scnsitivity ofthc proprio- ccptivc tlbcrs does reveal inflammation ofthe apical PDL. 6. A positive response to pcrcussion indicatcs not only thc prcscncc also thc cxlcnt ofthc inflamrratorv Droccss. of inflammation ofthc PDL. bu!

Endodontic procedures involve taking multiple radiographs. How should you protect yourself or your staff while taking radiographs if there is no barrier available to stand behind? Stand at least 4 feet away anywhere around the patient Stand at least 5 feet away exactly opposite the x-ray bearn source Stand at least 6 feet away and in the area that lies between 90 to 135 degrees to x-ray beam Stand at least 7 feet away and in the area that lies between 60 to 90 degrees to x-ray beam Never take an x-ray without a barner

Stand at least 6 feet away and in the area that lies between 90 to 135 degrees to x-ray beam Notes rclated to radiation safety and diagnostic radiographs: 1 . A fast (se sitive) filfir, lor example E-speed (Ektaspeed o|cr D ltlm (Ultraspee.l) as laster films require less radiation t ? r"Jr/ or Ektaspeed phts) film is preferred /rallJ exposure while providing quality image. r-ote: A newer F-spced. (Insigh, filrnhas been recently introduced that re- faboal quires 20% to 25% lcss cxposure than E-speed film but more studies need to be donc to access lhe usefulness ofthis new filrn type l. Dental units should operate at 70kV or higher. The higher the kV, the lower the patient's skin doses. \ote: The optimal setting formaximal contrast between radiopaque and radioluccnt structurcs is 70 kV. L Collimation fi.e., restfiction ofthe x-rq) beam size so that iL does not exceed 2.5 inches at the purient! skin, reduces exposure). J. Patient should be protectcd with a lead apron and a thyroid collar for each exposure. 5. If there is no barrier for thc clinician to stand behind while exposing films, hc/shc should stand in an area of minimal scatter r^diztiorr ( i.e., 6.feet otrat and i the area thot lies b, n'een 9(P to 135" to x-ray beam) 6. DeIltal personnel who may gct exposed to occupational x-radiation must wear fiLn badges to record exposurc and must never exceed the maximum permissible dose year/whole body. IMPD) of50 mSv per 7. An operator should never remain in the room holding an x-ray packet in place for a patient. lffilm must be held in place by somcone else (i.e.,lor a child.1, drape the patient and have him,/her hold the film. 8. The most accurate radiographs for endodontics are made using the paralleling technique. Remember: When using the paralleling technique, you must ccntcr the X-ray film packet behind, and parallel with the long axis ofthe tooth bcing X-rayed. The tube head must be posi- tioned so that the ccntral X-ray beam is projected perpendicular to the tooth and the lilm Packet.

Which defines the difference between a chronic apical abscess (CAA) and a periapical cyst/granuloma CAA is asymptomatic CAA is symptomatic Only histological examination can differentiate The border ofthe radiolucent lesion

The border ofthe radiolucent lesion The chronic apical abscess (also until revealed by an x-ray. It is a long-standing, low-grade infection ofthe periapical bone with the root canal b€ing the source ofthe inf'ection. This condition may follow an acule alveolar abscess or unsatisfactory root canal lherapy. Radiographs will reveal a diffusc radiolucency and PDL thickening. The tooth may be slighlly loose or tender to percussion. The chronic absccss may be differentitted fiom cysts and granulomas by the tact thatboth cysts andgranulomas have 1,ell'defincd radiolucencics associated with them. The trertment is conventional root crnrl treatment. R€member: 309/o ro 5070 ofbone calcium must bc altered before radiographic evidence ofperiapical break- do\rn occurs flrls .r//e/dtion takes place at tlrc The acute apical abscess (AAA) junction beireen the cortical dnd cancellous hone). is a localized collection ofpus in the rlveolar bone at the root apex follow- ing death ofthe pulp $ith extension ofthe infection into ihc pcriapical tissue. The first symptom may be a slight tendemess ofthe tooth. This later develops into a severe throbbing pain to percussion rdth swelling ofthe o|erhing mucosa. The tooth becomes more painful, elongalcd and loose. At timcs thc pain may dccrcase or disappcar complctcly. Thc paticnt may appcar wcakcned. irritable and present with a fever. Thc dirgnosis is bascd on lhe history. exam, and radiogmphs. The tooth \\,ill not r€spond to the EPT or cold test but may respond to heal The best treatm€nt ofan acute alveolar abscess includes establishing drainage and debrid- ing the canal s\ stem ofnecrotic fissue which will relieve the acute sy:nptoms. This is followed at a later date b\ con\ entional root canal therapy.\ote: Ifthe abscess rupores through the periosteum into thc soli tissue, the lrtic.fs svmproms *,ill subsidc. lncision and drainag€ of solt tissues in indicated; .lfa plthway is needed in soft tissues with localized fluctuant swelling that can provide necessary drainage. \ote: It should be emphasized that, rhenever possible, lhe acute periapical abscess should be incised and drained through the root canal system. . . When pain is caused by thc accunrulatjon ofexudat€ in tissues. wren it is necessary to obtain a cultr:re ofthc cxudatc Apical trep hin ation is accorr pl ished by aggress ively p lacing a No. I 5 to 2 5 K-fi lc bcyond the confincs of the apex. Surgical trephination is a perforation of thc alveolar cortical bone to release accumulatcd tissue exu- dates. A small /J-lr/r/ horizontal inc ision is made with a No- I 5 scapel bl ade at ihe I e! el sl ightly apical to the root apex. ANo. 6 or 8 round bur is uscd on a stmight handpiece to penetrate apex. Iftherc is diffusc swclling f.e11 /irrt, antibiotics are usually indicated. the conical plate above the root

The cervical cross section of the pulp cavity below represents which tooth (SEE PIC pg47) The permanent maxillary right first molar The permanent maxillary right second molar The permanent maxillary right third molar The permanent maxillary right first premolar

The permanent maxillary right second molar NOTE: MANY MORE OF THESE TYPES OF Qs from pg 47-55

Intentional replantation is often used when RCT fails because it allows canal and/or apical erparation/filling to be done outside of the mouth. Both the statement and the reason are correct and related Both the statement and the reason are correct but NOT related The statement is correct, but the reason is NOT The statement is NOT correct, but the reason is correct NEITHER the statement NOR the reason is correct

The statement is NOT correct, but the reason is correct Intentional replartation implies that a tooth requiring cndodontic therapy is purposcly removed ftom its socket, son]e type ofcanal or apical preparation and/or filling is perfonned, and thc tooth is returned to its original socket. Indications lbr intentional replantation falso . . called replant vugery); When routine endodontic therapy of a tooth is impractical or impossible When an obstruction of a canal is prcscnt. such as a broken instrument or a calcification, and periapical surgery is impractical (e.g-, a lower molar w'ith the mandibular canal in close pro* inin . . When perforating internal or external resorption is present, yet surgery is impractical When a previous lreatment has failed but nonsurgical treatment or surgery is impractical Note: lntentional replantation should be considered only when there's no other alternative treat- "strategic" tooth. Long term follow up is required to monitor for complications including periodontal defccts and ankylosis with replacemcnt rcsorption. ment to maintain a Other surgical endodontic procedurcs. . Bicuspidization: is a process in which a tooth is divided into mesial and distal halves without removal ofany. Endodontic treatment is done and two separate crowns are fixed on both halves. It is perfomred on mandibular molars with furcation involvement. Better stability ofthe tooth is achieved when their roots are divergent. . Hemisectioni is the division of a mandibular molar buccolingually into two single-rooted tceth: the defective root is extracted. Hemisection requircs root canal therapy on all rctained root sesments. Note: When possible, it is prefcrablc to complete the root canal trcatment and place a . pemranent restoration into the canai odlices prior to the hemisection. Root amputation: ref'ers to the removal ofa rcot from any molar without sectioning through thc crown. Root amputation requires root canal therapy on all retained root segments. . Surgical removal of the apical segment of a fractured root: performed on a tooth when a root fractwe occurs in the apical portion and pulpal necrosis results. Note; The coronal looth seg- ment must be restomble and functional or else this procedure is worthless.

A patient is diagnosed with acute apical periodontitis but refuses treatment due to fear of needles, your statement to the patient should include the fact that Eventually the acute nature ofthe lesion will progress into a chronic, and non-painful lesion This lesion can progress into the bone causing osteomyelitis, a more severe condition The apical lesion has been there for years and the tooth needs treatment immediately

This lesion can progress into the bone causing osteomyelitis, a more severe condition Osteomyelitis is not a particularly common disease. It is a serious sequela of periapi- cal infection that often results in a diffuse spread of infection throughout the medullary spaces, with subsequent necrosis ofa variable amount ofbone. Acute or subacute osteomyelitis may involve either the maxilla or the mandible. In the maxilla, the disease usually remains fairly wellJocalized to the area of initial infection. In the mandible, bone involvement tends to be more diffuse and widespread. Clinically, the person afllicted with acute osteomyelitis is usually in rather severe pain and manifests an elevation of temperature with regional lymphadenopathy. The teeth in the area of involvement are loose and sore so that eating is difficult, if not irnpossible. Note: Another clinical symptom ofacute osteomyelitis is leukocytosis, an elevated num- ber of white cells in the blood. Radiographically, acute osteomyelitis progresses rapidly and demonstrates little radiographic evidence of its presence until the disease has developed for at least one to two u eeks. At that time, diffuse lytic changes in the bone begin to appear Note: A eaten" radiolucent aooearance is evident. The general principles of treatment demand that drainage be established and main- tained and that the infection be fteated with antibiotics to prevent further spread and complications.

The most acceptable method to achieve adequate root canal debridement To obtain clean shavings of the canal To attain a clean irrigating solution To achieve glassy smooth walls of the canal All ofthe above criteria are reliable None ofthe above criteria is acceptable

To achieve glassy smooth walls of the canal Clean shavings are difficult to see on a file. The attainment of a clean irrigating so- lution is considered an inaccurate way to determine the end point ofdebridement. Debridement is defined as the removal offoreign material and contaminated or devital- ized tissue from or adjacent to a traumatic infected lesion until surounded healthy tissue is exposed. Chemomechanical debridement of the root canal system is the most crucial aspect ofroot canal treatment. Complete debridement of the canal is the most effective means to reduce root canal microorganisms. It can be carried out in various ways as the case demands, and may in- clude instrumentation ofthe canal, placement ofmedicaments and irrigants antVor surgery Remember: . The most common cause ofroot canal failure is incompletely and inadequately disin- fected root canal systems. . The second most common cause of failures ol root canals is leakage from a poorly filled canal. This is common even after apical curettage. Example: Root canal treat- ment performed on a tooth with apical curettage ofa lesion that was found to be a cyst. Three years later the lesion is even bigger than it was before. The most likely cause of this lailure is leakage from a poorly filled canal. . A ledge is an artificially created irregularity on the surface ofthe root canal wall which prevents the placement ol instruments at the apex ofan otherwise patent canal. Ledging is caused by insertion ofuncurved instruments sl'lort ofthe working length with excessive amounts ofapical pressure. The canal wall is gouged or a false canal is created which re- sults in ledge formation. The effective use ofcircumferential filing, especially with Hed- strom files, will ensure smoothness and occlusal flaring ofthe canal walls and prevent the derelopment of steps or irregularities.

Which of the following teeth is most likely to have two canals, in fact it has two canals most of the tlme? Tooth #14 Tooth #12 Tooth #20 Tooth #28

Tooth #12 Maxiffary first premolars: Approximately 78oh have two roots, one buccal and the other palatal, each rvith a single canal. The two roots rnay be completely separate or merely twin projections rising from the middle third ofthe root to the apex (this is nore comrD,?). The two roots are usually equal in iength from apex to cusp. However, the lingual root and canal may be wider. ln approximately 229lo of maxillary first premolars, only one root is present. there may either be one or trlo canals with one foramen. A cross section at the cervical line shows a canal shaped like a figure eight forate on the mesial (the /e//rpse). The access opening is a thin oval. Be careful not to per- concavii, on the mesial makes perforation reD'conmon). The apical foramen ofthe maxillary first premolar is usually close to the anatomic apex, and rhe apical ponion ofthe roots often taper rapidly, ending in extremely narrou and curved root rips. The buccal root can fenestrate through the bone, leading to problems such as inaccurate aper location. chronic post-operative sensitivity to palpation over the apex, and increased risk ofan irrigation accident. This tooth is also prone to mesiodistal root fractures and fiactures at rhe base ofthe cusps, especially the buccal cusp. Nlarillary second premolars: The most common configuration in this tooth is a single root, occurring approximately 75%o ofthe time. Approximately 25%o ofthe time, two separate roots are present, each \\,ith a single canal. The access opening is exactly the same as that for max- illary first premolars (thin oval). Remember: Maxillary second premolars have a higher incidence ofaccessory canals (60'%), than do maxillary first premolars. , .. f. When onlyonecanal is present (frst or secotld premolar), it is usually found in rNolce.i fis center ofthe access preparation. lfonly one canal is found, but it is not in the '*i4d;i center ofthe tooth, it is probable that another canal is present 2. Overfilling either tooth may force materials directly into the maxillary sinus.

A patients central incisors are intruded. Which of the following is the least useful examination technique? Soft tissue exam Hard tissue exam Radioglaph Vitality test Percussion test

Vitality test This test is contraindicated. The pcrcussion test is usually not performed bccause ofits paini however the vitality test will givc you a truly falsc reading, bccause oftcmporary area- For teeth that have becn recently traumatized the dental examination should include: . . Soft tissue exam: observc the lips, face, tongue, etc. Hard tissue exam: visually look and then palpate thc injured tooth and alveolus to reveal thc extent oftooth mobility as well as alveolar fractures and area of inllammation. check for occlusal disharmonies to hclp detcct tooth displacements andjaw fractures . Radiographic examination; x-rays reveal tooth displacsment and root fracturcs as well as other important facts (previous rc,ot canal, periapical radioluce cies, elc.). . Observe the adjacent and opposing tceth for injury' Teeth that have been traumatized n,lay bc fine for a long tine. however, nany rvill develop radi- pulp vitality' and perform root canal thcrapy only in those teeth that do not rcspond to pulp testing Example: Trauma to olucencies. Do not indiscriminately do root canals without first checking maxillary anterior tcclh. A fcw years latcr x-rays rcveal radiolucencics around the region of thc apices ofthe incisors. Check the pulp vitality ofall anterior teeth before performin-q root canals' Note: Trauma tc4r., iry deep intnrsion) to a paresthesia in the permancnt tooth will most likely result in necrosis of the pulp and conventional root canal therapy will be necessary. Pulpal necrosis: ifcaused by inflammation that started in the pr.rlp /e 81., cdrie.t/, it most probably will spread to the periradicular tissues; ifcaused by trauma that severs the blood supply to the tooth, a dry necrosis rnay result that may not spread to the pcriradicular tissues. [t rnay be partial or total: partial necrosis may (e.g., present with somc of the symptoms associated with ireversiblc a fito-.anale.l tooth could hare an inJlamed pulp in one canal and a necrotic pulp itl the otrer. Total necrosis is asymptomatic before it affects the PDL, and there is no rcsponse to thcrmal or clectric pulp tests. Note: The inflammation will eventually spread beyond the apical fora- men. which rvill lcad to thickening of the PDL. The clinical manifestation of this presents as tendemess to percussion and biting

A patient wlks into your office holding a cup with a tooth in it. What liquid would you least hope the patient left it in Milk Water Saliva Saline

Water mportant: Thc first priority oftrcatmcnt ofavulsion irturics is 1o prorecr thc viabilir)--. of thc pcriodontal ligamcnt. Five factors thnt arc critical lo Ihc managcnrcnl oftraumatic avulsion injurics lo tccthl L Timei thc time intcnal from injury ro rcplacemcnt ofrhc looth is a major lactor in rhc maintc|ancc of liga- mcnt \ irbility and subscqucDl rft)t rcsorption. Tccth rcplantcd \l ilhin l0 mimurcs have been rcportcd ro cxhibil vcry littlc rcsorpiion, u hcrcas most oflhe tccth rcplantcd aficr 2 hours sho* a lot ofcxtcmat roor rcsorprion ,,r,r,(, r, Ih" nail uus? ol fui1uft 4 rcpla r?d teeth). L Storage mcdia: ii thc toolh cannot bc imm€diatcly rcplanlcd, thc prcpcr sloragc ofthc ioolh c?n favorablv influence thc viabilitv ofPDLcells. Milk is considcrcd bcst fbrlhis purposc 6 lr I bccausc ofils ncarn€utralpH rnd osrrolality. conducilc ibr the sur,"jval otcclls. Othcr storagc mcdia.rre physiologic salinc and snliva. -lboth d:!rta .l socket: should not bc dam.rgcd by curctlttgc or fbrccful rcplantarion. Replanl slowly $i1h slight nr.sLrrc Splint stabilization: a splint that allo\rs drc physiologic movcment is placcd -'l,.L/r.irxl.rr.Thistimcpcriodallowslbrthcinitialrcarrachnrcntofrhcpcriodontat j Root surfacci should not bc sc.apcd. dricd. or manipulatcd with causlic chcmicals. Imporianti . T.n drvs ro n\o *ccks rtlcr rcplartation. tbc roor canal is prcparcd (Lleunrd dro\ide paste is placcd into rhc cdnals . . This rastc rs replaced ev€rv three montbs for onc ycar If after one tear, it appcars that rcsorption has rcvcrscd or stoppcd. a fbr a maximum of I \\,ccks tigamcnt ilbcrs. utkl rr.rp€././ and a catcium ht, pcrmancnt gurta-pcrcha Ulling can bc \ote: The abovc informalion changes *hcn a tooth has bccn oul of thc mouth for more than 2 hours mainly the trcahcnt ofthc looth sockct and root surf-aces. Changcs rrc as follows: . Ankvlosis and erternal root resorption x'ill probably resulr withln hvo vcars. Ank]lojis rcsuhing iiom rc- placcrrcnt would give . . Root canal thcrapy is a bcttcr prognosis pcrlbrmed than external resorption, which u ill lcad ro farture. in irs cntircty prior to rcplantatjon Thc looth is soaked in a 2.470 fluoride solution acidulat€d at pII 5.5lbr t0 minutcs or nrorc. Thc fluoridc \ri slow the resorpli\c proccss. . . . Gentll curctte blood clot out ofthc alveolar sockc( and irrigate with saline RcplaDt slo*4y wi(h slighl digital pressuru Stabilizc wjlh splint for a maxin]um of2 wccks (7 b lA ddrs is irteal)

One year after performing endo treatment on #3, you take a new periapical radiograph and see that the lesion is still there. Whats most likely the problem. You failed to locate a second mesiobuccal calal You failed to locate a second distobuccal canal You failed to locate a second palatal canal Nothing, it takes more than 12 months for the bone to heal

You failed to locate a second mesiobuccal calal Not only is the mesiobuccal canal the hardest canal to find on tooth #3 and # 1.1, but it also olten splits into t\,'o. Canal orifices ofa maxillary first molar are arranged in the shape ofa triangle. Tlie ori- fice to the mesiobuccal canal is usually the most difficult to locate, since it is under the mesiobuccal cusp and must be entered frorn a distolingual position. This canal is the small canal and often splits into two canals. lt may be calcified and difficult to instru- ment. The palatal canal is the straightest, widest, and most tapering canal. The most common curvature ofthe nalatal root is to the facial. The distobuccal canal is also small and tapering. The orifice to this canal has no direct relation to its cusp. The distobuccal ori- fice is usually located by means of its relation to the mesiobuccal orifice, t\.'ith the distobuccal found approxinately 2 to 3 mm to the distal and slightly to the palatal aspect of the mesiobuccal orifice. Note: In approximately 587o ofmaxillary first molar teeth, a fourth canal is present with its orifice being just lingual to the orifice ofthe mesiobuccal canal. The canal is located in the rlesiobuccal root and may join the mesiobuccal canal or exit through a separate fbramen. lf a lesion is present on the mesiobuccal root pior to root canal therapy and doesn't heal in the usual amount of time (6-12 month.s) following treatrnent, il is rnost likely due to a missed canal (nesiolingual). Fracture ofthe maxillary first molar is usually through the central groove or at the base ofthe buccal cusp. These fractures can extend into the furcation, creating an untreatable periodontal det'ect. Remember: The U-shaped radiopacity commonly seen overlying the apex ofthe palatal root of the maxillary first molar is most likely the zygomatic process ofthe maxilla.