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Home , Mandibular first molar, Mandibular second molar, Maxillary first premolar, Maxillary second molar, Pulp (tooth)

Earn 4 CE credits This course was written for dentists, dental hygienists, and assistants.

Guidelines for Access Cavity Preparation in A Peer-Reviewed Publication Written by Ricardo Caicedo; Dr. Odon; Stephen Clark, DMD; Liliana Rozo, DDS and Joseph Fullmer, BA

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This course has been made possible through an unrestricted educational grant. The cost of this CE course is $59.00 for 4 CE credits. Cancellation/Refund Policy: Any participant who is not 100% satisfied with this course can request a full refund by contacting PennWell in writing. Educational Objectives 1. To achieve straight-line access to study demonstrated the existence of a Upon completion of this course, the or to the initial specific and consistent anatomy of the the clinician will be able to do the curvature of the canal chamber floor. These authors pro- following: 2. To locate all orifices posed five guidelines, or laws, of pulp 1. Understand access as the most 3. To conserve sound structure chamber anatomy to help clinicians important phase of nonsurgical determine the number and location of The ideal access cavity creates a orifices on the chamber floor. In order 2. Comprehend principles of smooth, straight-line path to the canal to accurately prepare and properly fill cavity preparation and proposed system and ultimately to the apex. the radicular pulp space, intracoronal guidelines to accurately prepare When prepared correctly, the access preparation must be correct in size, and fill the radicular pulp space cavity allows complete irrigation, shape, and inclination. Deutsch and 3. Understand the four parts to shaping, cleaning, and quality obtura- Musikant3 studied the morphology of endodontic coronal cavity prepara- tion. Optimal access results in straight the chamber and found that the ceiling of tion—outline form, convenience entry into the canal orifice, with the the pulp chamber was at the level of the form, removal of remaining carious line angles forming a funnel that drops in 97 percent and defective restorations, smoothly into the canal(s). Projection to 98 percent of the maxillary and man- and cleansing of the cavity of the canal center line to the occlusal dibular molars. These findings should 4. Understand the differences in surface of the tooth indicates the loca- be integrated during the endodontic chamber and access shape for each tion of the cavosurface line angles. access preparation. tooth type and protocol to follow Connection of the line angles creates Developments in electric hand- when performing on each the outline form. piece engineering allow one motor Green V. Black’s principles of cavity to provide both low- and high-speed Abstract preparation, including outline, conve- utility. For initial entrance of the Adequate access is essential for success- nience, retention, and resistance forms, coronal cavity preparation through ful endodontic treatment. Knowledge should be applied while thinking of an the enamel surface or through a res- of pulp chamber morphology, along endodontic preparation as a continuum toration, the ideal cutting instrument with an examination of preoperative from enamel surface to apex (Figure 1). is a round-end carbide fissure bur.4 radiographs, should be integrated The entire length of the preparation is With this instrument, enamel, resin, when designing the access cavity to a the full outline form. Sometimes, this ceramic, or metal perforation is easily tooth for nonsurgical root canal treat- outline may have to be modified for accomplished, and surface extensions ment. Once the coronal cavity has been the convenience of a canal anatomy, may be rapidly completed (Figure adequately prepared, including the radicular dilacerations, or insertion of 2). Manufactured models of this in- removal of carious dentin and defective endodontic instruments.1 strument include Maillefer Endo Z restorations, a variety of instruments In a study involving 500 pulp cham- bur (Dentsply/Maillefer, Tulsa, can be used in the process itself. Great bers, Krasner and Rankow2 found that Okla.), LA Axxess Diamond (Syb- variance in overall tooth size, mor- the cementoenamel junction (CEJ) was ron-Endo), Brasseler H269GK, Axis phology, and arch position means that the most important anatomic landmark Dental H269GK-FG, and Meisinger no two access openings are identical, for determining the location of pulp HM23R. For the clinician to master although common access guidelines chambers and root canal orifices. The the anatomic concept of cavity prepa- have been established depending on A the location of the tooth. This article is B a review of the endodontic access and C A anatomic landmarks relating to the B pulp chamber. C Access is the most important phase of nonsurgical root canal treatment. A well-designed access preparation is E essential for an optimum endodontic result. Without adequate access, instru- D ments and materials become difficult to handle properly in the highly complex and variable root canal system. The Figure 1 objectives of access cavity preparation consist of the following: Figure 2

2 www.ineedce.com ration, he must develop a mental three- 3. Cavity expansion to accommodate dimensional image of the interior of the filling techniques, and tooth, from the pulp horn to the apical 4. Complete authority over the foramen (Figure 3). Unfortunately, enlarging instrument (Figure 5).6 conventional radiographs provide only a two-dimensional image of pulp III. Removal of the Remaining anatomy. It is the third dimension that Carious Dentin and Defective the clinician must mentally visualize, Restorations as a supplement to two-dimensional Caries and defective restorations thinking, if one is to accurately clean, remaining in an endodontic cavity shape, obturate, and fill the total pulp preparation must be removed for space (Figure 4). The anatomy of the three reasons: canals dictates modifications of the 1. To mechanically eliminate as cavity preparation. If, for example, a many bacteria as possible from the Figure 3 fourth canal is found or suspected in interior of the tooth a tooth, the preparation outline 2. To eliminate the discolored tooth will have to be expanded to allow for structure that may ultimately lead easy access into the accessory canal. to staining of the Endodontic preparations deal with 3. To reduce the risk of bacterial both coronal and radicular access, contamination of the prepared each of which is achieved separately cavity but ultimately flow together into a single preparation. IV. Cleansing of the Cavity Figure 4 All of the caries, debris, and necrotic Endodontic Coronal material must be removed from the Cavity Preparation5 chamber before the radicular instru- I. Outline Form mentation is begun. This should be done II. Convenience Form without the use of an air syringe due to III. Removal of the Remaining the possibility of an air embolism. Sodi- Carious Dentin and Defective um hypochlorite (NaOCl) should also Restorations be used during the access preparation Figure 5 IV. Cleansing of the Cavity for its added benefits of disinfection, removal of hemorrhagic or purulent I. Outline Form fluids, and flushing action of debris and The access opening is triangular, The outline form of the endodontic dentin chips. similar to maxillary central , cavity must be correctly shaped and and proportionately smaller in the positioned to establish complete access Common Access7 middle third of the lingual surface of for instrumentation, from cavosurface the tooth. A lingual ledge may also be margin to apical foramen. Maxillary Central Incisors present but is usually not clinically The morphology of the chamber is significant. If a lingual shoulder of II. Convenience Form triangular in design with high pulp dentin is present, it must be removed Convenience form, as conceived by horns on mesial and distal aspects of before instruments can be used to Black, is a modification of the cav- the chamber. The access opening is explore the canal (Figure B). ity outline form to establish greater triangular in shape. The outline form of convenience in the placement of intra- the access cavity changes to a more oval coronal restorations.1 In endodontic shape as the tooth matures and the pulp The chamber shape is usually elliptical therapy, however, this form provides horns recede because the mesial and or oval. The access opening is oval on more convenient and accurate prepara- distal pulp horns are less prominent. the lingual surface and should be in the tion and filling of the root canal. Four A lingual ledge or lingual bulge is often middle third of the tooth, both mesio- important benefits are gained through present (Figure A). distally and incisal-apically. Because convenience form modifications: of its shape, the clinician must take 1. Unobstructed access to the Maxillary Lateral Incisors care to circumferentially file the access canal orifice, The chamber is similar to central opening labially and palatally to shape 2. Direct access to the apical foramen, incisors but proportionately smaller. and clean the canal properly. A lingual www.ineedce.com 3 ledge may be present but is usually not marginal ridge, within the middle one- be invaded. Because the tendency in clinically significant (Figure C). third buccolingually, and mesial to the maxillary second molars is for the dis- transverse ridge. Care should be taken tobuccal orifice to move closer to a line Maxillary First not to undermine the transverse ridge connecting the MB and P orifices, the The chamber is usually oval and main- during preparation or to extend the triangle becomes more obtuse and the tains a similar width from the occlusal access opening so far mesially as to oblique ridge is normally not invaded. level to the floor, which is located just undermine the mesial marginal ridge. If only two canals are present, the ac- apical to the cervical line. The palatal The palatal canal orifice is centered cess outline form is oval and widest in orifice is slightly larger than the buccal palatally, the distobuccal orifice is near the buccolingual dimension. Its width orifice. In cross section at the CEJ, the the obtuse angle of the pulp chamber corresponds to the mesiodistal width of palatal orifice is wider buccolingually floor, and the main mesiobuccal canal the pulp chamber, and the oval usually and kidney-shaped because of its me- orifice (MB-1) is buccal and mesial to is centered between the mesial pit and sial concavity. The access opening is the distobuccal orifice positioned with- the mesial edge of the oblique ridge oval on the occlusal surface and should in the acute angle of the pulp chamber. (Figure G). be in the middle third of the tooth, The second mesiobuccal canal orifice both mesiodistally and buccolingually. (MB-2) is located palatal and mesial to Maxillary Third Molar Buccal and lingual cusps should not the MB-1. A line drawn to connect the The chamber is usually less triangular be undermined during access opening three main canal orifices—MB orifice, and more oval in shape than the maxil- preparation. The buccal pulp horn distobuccal (DB) orifice, and palatal lary second molar. The access opening usually is larger. There are often ledges (P) orifice—forms a triangle known as is somewhat triangular, but tends to of calcification on the buccal and/or the molar triangle (Figure F). rotate as the DB canal orifice becomes lingual walls just coronal to the orifice more aligned with the palatal canal. that may inhibit straight-line access to Preparation can begin in the central the canal system (Figure D). This shape of this chamber is usu- fossae and proceed in a buccopalatal ally less triangular and more oval than direction. The access cavity form Maxillary Second Premolar the . The access for the third molar can vary greatly, The chamber morphology is usually opening is triangular, but becomes because the tooth typically has one to oval. A buccal and a palatal pulp horn more straightened in a mesiobuccal- three canals that would require the ac- are present; the buccal pulp horn is palatal direction. Preparation of the cess preparation to be anything from an larger. The access opening is oval on access should be distal to the mesial oval that is widest in the buccolingual the occlusal surface and should be in marginal ridge, within the middle one- dimension to a rounded triangle similar the middle third of the tooth, both third buccolingually, and mesial to to that used for the maxillary second mesiodistally and buccolingually. The the transverse ridge. Care should be molar. The MB, DB, and P orifices buccal and lingual cusps should not taken not to undermine the transverse often lie nearly in a straight line. The be undermined during access opening ridge during preparation. The opening resultant access cavity is an oval or a preparation. The single root is oval and begins slightly more distally than in very obtuse triangle (Figure H). wider buccolingually than mesiodistal- the first molar because of the location ly, so the canal(s) remains oval from the of the canal and root structure. When Mandibular Central and pulp chamber floor and tapers rapidly four canals are present, the access cav- Lateral Incisors to the apex (Figure E). ity preparation of the maxillary second The chamber shape is triangular to oval molar has a rhomboid shape and is a in design, with high pulp horns on me- Maxillary First Molar smaller version of the access cavity for sial and distal aspects of the chamber The chamber is usually triangular the maxillary first molar. If only three in younger patients. A lingual ledge or or square, and the access opening is canals are present, the access cavity is lingual bulge may be present, which re- triangular to slightly square on the a rounded triangle with the base to the stricts visualization of the canal orifice occlusal surface. Preparation of the buccal. As with the maxillary first mo- and prevents straight-line access of the access should be distal to the mesial lar, the mesial marginal ridge need not canal system. Often, the access open-

MB-1

MB-2

Figure A Figure B Figure C Figure D Figure E Figure F

4 www.ineedce.com Figure G Figure H Figure I Figure J Figure K Figure L ing must be extended more lingually in of the tooth for straight-line access, and tion. There are at least two variations order to obtain straight-line access to the gingival extension must penetrate in the external anatomy that affect the the lingual orifice and the canal system. the cingulum to allow a search for a access cavity form of the mandibular In addition, all working length films possible lingual canal. As with the second premolar. First, because the taken of mandibular incisors should be mandibular incisors, butt joint rela- crown typically has a smaller lingual exposed at a slight mesial or distal angle tionships between internal walls and inclination, less extension up the buc- to confirm the presence or absence of a the lingual surface are not necessary cal incline is required to achieve second canal. Due to their small size (Figure J). straight-line access. Second, the lingual and internal anatomy, the mandibular half of the tooth is more fully devel- incisors may be the most difficult ac- Mandibular First Premolar oped. Consequently, the lingual access cess cavities to prepare. The external The chamber shape is usually oval or extension is typically halfway up the outline form may be triangular or oval, rounded, as is the access opening on lingual cusp incline. The mandibular depending on the prominence of the the occlusal surface. As in many other second premolar can have two lingual mesial and distal pulp horns. When circumstances, above, the access open- cusps, sometimes of equal size. When the form is triangular, the incisal base is ing should be in the middle third of the this occurs, the access preparation is short and the mesial and distal legs are tooth, both mesiodistally and buccolin- centered mesiodistally on a line con- long incisogingivally, creating a long, gually. Whenever possible, the buccal necting the buccal cusp and the lingual compressed triangle. Without promi- cusp should be preserved without be- groove between the lingual cusp tips. nent mesial and distal pulp horns, the ing undermined during access opening When the mesiolingual cusp is larger oval external outline form also is narrow preparation. The oval external outline than the distolingual cusp, the lingual mesiodistally and long incisogingivally. form of the mandibular first premolar extension of the oval outline form is Complete removal of the lingual shoul- is typically wider mesiodistally than its just distal to the tip of the mesiolingual der is critical, because this tooth often maxillary counterpart, making it more cusp (Figure L). has two canals that are buccolingually oval and less slot-shaped. Because of oriented, and the lingual canal is most the lingual inclination of the crown, often missed. To avoid this, the clini- buccal extension can nearly approach The chamber is usually triangular to cian should extend the access prepara- the tip of the buccal cusp to achieve square in shape. The access opening tion well into the cingulum gingivally. straight-line access. Lingual extension is triangular to slightly square on the Because the lingual surface of this tooth barely invades the poorly developed occlusal surface, and its preparation is not involved with occlusal function, lingual cusp incline. Mesiodistally, the should be distal to the mesial marginal butt joint junctions between the inter- access preparation is centered between ridge and primarily within the mesial nal walls and the lingual surface are not the cusp tips. Often the preparation half of the occlusal surface, keeping required (Figure I). must be modified to allow access to the in mind that the distal extension of complex root canal anatomy frequently the access opening should extend into seen in the apical half of the tooth root the distal half of the tooth. The access The morphology of the chamber is (Figure K). cavity for the mandibular first molar usually elliptical or oval, and a lingual is typically trapezoid or rhomboid ledge may be present. The access Mandibular Second Premolar regardless of the number of canals opening is oval on the lingual surface As with the mandibular first premolar, present. When four or more canals and should be in the middle one-third the chamber morphology is usually oval are present, the corners of the trap- of the tooth, both mesiodistally and or rounded, as is the access opening on ezoid or rhombus should correspond incisal-apically. Preparation of the ac- the occlusal surface. Additionally, the to the positions of the main orifices. cess cavity for the mandibular canine access opening should be in the middle Mesially, the access need not invade is oval or slot-shaped. The mesiodistal third of the tooth, both mesiodistally the marginal ridge. Distal extension width corresponds to the mesiodistal and buccolingually, and the buccal and must allow straight-line access to the width of the pulp chamber. The incisal lingual cusps should not be under- distal canal(s). The buccal wall forms extension can approach the incisal edge mined during access opening prepara- a straight connection between the MB www.ineedce.com 5 shapes. When three or more canals are capability. JOE 1997;23:75. present, a traditional rounded triangle 5. Ingle JI, Bakland LK. Endodontics, 5th ed. Hamilton London; BC Decker, or rhombus is typical. When two ca- 2002:405. nals are present, a rectangle is used, 6. Reeh ES, et al. Reduction in tooth stiffness and for single-canal molars, an oval. as a result of endodontic and restorative Figure M Figure N Significant ethnic variation can be procedures. JOE 1989;15:512. 7. Cohen S, Hargreaves KM. Pathways of seen in the incidence of C-shaped root the pulp, 9th ed. Elsevier; 2006:173. and DB orifices, and the lingual wall canal systems. This anatomy is much 8. Kotoku K. Morphological studies on the connects the ML and DL orifices more common in Asians than Cau- roots of the Japanese mandibular second without bowing (Figure M). casians. Investigators in Japan8 and molars. Shikwa Gakuho 1985;85:43. 9. Yang Z-P, Yang S-F, Lee G. The root and 9 China found a 31.5 percent incidence root canal anatomy of maxillary molars of C-shaped canals. Others found the in a Chinese population. Dent Traumatol The chamber morphology is usually occurrence of C-shaped canals in a 1998;4:215. triangular. The opening of the access Chinese population to be 23 percent 10. Haddad GY, Nehma WB, Ounsi HF. Diagnosis, classification and frequency is triangular, but tends to straighten in in mandibular first molars and 31.5 of C-shaped canals in mandibular second a mesiodistal direction if two separate percent in mandibular second molars. molars in the Lebanese population. J orifices are not present in the mesial Another study found an incidence rate Endodon 1999;25:268. root. Preparation should be distal to of 19.1 percent in Lebanese subjects,10 11. Seo MS, Park DS. C-shaped root canals of mandibular second molars in a the mesial marginal ridge and pri- whereas a different investigation Korean population: clinical observation marily within the mesial half of the found that 32.7 percent of Koreans and in vitro analysis. Int Endodon J occlusal surface, although the distal had a C-shaped canal morphology in 2004;37(2):139. extension of the access opening should mandibular second molars.11 The ac- extend into the distal half of the tooth. cess cavity for teeth with a C-shaped Author Profile When three canals are present, the root canal system varies considerably All four of the authors are affiliated access cavity is very similar to that for and depends on the pulp morphology with the School of at the the mandibular first molar, although of the specific tooth. These teeth pose University of Louisville in Louis- perhaps a bit more triangular and less a considerable technical challenge; ville, Kentucky. Dr. R. Caicedo is a rhomboid. The distal orifice is less however, use of the DOM, sonic professor of Graduate Endodontics often ribbon-shaped buccolingually; and ultrasonic instrumentation, and and director of the Junior End- therefore, the buccal and lingual walls plasticized obturation techniques odontics Course; Dr. S. Clark is a converge more aggressively distally to greatly increase the likelihood of a professor and director of the Gradu- form a triangle. The second molar may successful treatment. ate Endodontic Specialty Program; have only two canals, one mesial and Dr. L. Rozo is a professor in the one distal, in which case the orifices Conclusion Department of Diagnostic Sciences, are nearly equal in size and line up in Adequate access is essential for suc- Prosthodontics and Restorative the buccolingual center of the tooth. cessful non-surgical endodontic treat- Dentistry; and Mr. J. Fullmer is a The access cavity for a two-canal ment. A straight line to the canal system fellow researcher and junior dental second molar is rectangular, wide me- that ultimately leads to the apex may student. siodistally and narrow buccolingually. achieve optimal results when it is based The access cavity for a single-canal on knowledge of the internal morphol- Illustrations mandibular second molar is oval and ogy and observance of the principles of All illustrations created by Briar is lined up in the center of the occlusal cavity preparation. Lee Mitchell surface (Figure N). References Disclaimer Mandibular Third Molar 1. Black GV. Operative dentistry. 7th ed. Vol II. The authors of this course have no The morphology of the chamber is Chicago: Medico-Dental Publishing; 1936. commercial ties with the sponsors or 2. Krasner P, Rankow HJ. Anatomy of usually less triangular and more oval the pulp chamber floor. Journal of the providers of the unrestricted edu- than the mandibular second molar. Endodontics (JOE) 2004;30(1):5. cational grant for this course. The access opening is also triangular 3. Deutsch AS, Musikant BL. Morphological to oval, with a pulp chamber that measurements of anatomic landmarks in Reader Feedback human maxillary and mandibular molar tends to be very large and very deep. pulp chambers. JOE 2004;30:388–90. We encourage your comments on this or The anatomy of the mandibular third 4. Kobayashi C, Yoshioka T, Suda H. A any PennWell course. For your conve- molar is very unpredictable, and the new engine-driven canal preparation nience, an online feedback form is avail- access cavity can take any of several system with electronic canal measuring able at www.ineedce.com.

6 www.ineedce.com Questions

1. The most important phase of nonsurgical 12. The outline form of the access cavity for 21. Visualization of the canal orifice and root canal treatment is: maxillary central incisors changes to a straight-line access of the canal system for a. Cavity preparation more oval shape as the tooth matures and mandibular central and lateral incisors are b. Access the pulp horns recede. restricted due to the presence of: c. Pulp chambers a. True a. High pulp horns on distal aspects of chamber d. All of the above b. False b. High pulp horns on mesial aspects of chamber c. A lingual ledge 2. When prepared correctly, the access cavity 13. In maxillary lateral incisors, d. None of the above allows complete irrigation, shaping, clean- the chamber is: ing, and quality of obturation. a. Triangular in shape 22. With mandibular central and lateral a. True b. Proportionately larger in the middle third of the incisors, complete removal of the lingual b. False lingual surface of the tooth shoulder is inconsequential, because this c. Both of the above tooth often has two canals that are buc- 3. The principles of cavity preparation should d. None of the above colingually oriented, and the lingual canal be applied while thinking of an endodontic is often missed. preparation as a continuum from enamel 14. Due to the shape of the maxillary canine chamber: a. True surface to apex. These principles include: b. False a. Retention a. The buccal and lingual cusps should not be b. Outline undermined during access opening preparation. 23. For the mandibular canine, c. Resistance forms b. The oval is usually centered between the mesial pit the access opening: d. All of the above and the mesial edge of the oblique ridge. a. Should be in the middle third of the tooth, both c. The access opening must be filed labially and mesiodistally and buccolingually 4. Shape, size, and inclination must be correct palatally to shape and clean the canal properly. b. Should be in the middle third of the tooth, both in intracoronal preparation in order to: d. Preparation of the access should be distal to the mesiodistally and incisal-apically a. Study the morphology of the chamber mesial marginal ridge. c. Is usually oval or rounded b. Mentally visualize the third dimension 15. Due to the shape of the maxillary first d. None of the above c. Accurately prepare and properly fill the radicular premolar chamber: 24. For the mandibular first premolar, pulp space a. The buccal and lingual cusps should not be the access opening: d. Determine the location of pulp chambers and root undermined during access opening preparation. a. Should be in the middle third of the tooth, both canal orifices b. The oval is usually centered between the mesial pit mesiodistally and buccolingually 5. The clinician must develop a two-dimen- and the mesial edge of the oblique ridge. b. Should be in the middle third of the tooth, both sional visual in order to fully understand c. The access opening must be filed labially and mesiodistally and incisal-apically the anatomic concept of cavity preparation, palatally to shape and clean the canal properly. c. Is usually oval or rounded d. Preparation of the access should be distal to the d. None of the above as the endodontic cavity preparation and mesial marginal ridge. pulp anatomy are inseparable. 25. For the mandibular second premolar, a. True 16. Due to the shape of the maxillary second the access opening: b. False premolar chamber: a. Should be in the middle third of the tooth, both a. The buccal and lingual cusps should not be mesiodistally and buccolingually 6. Endodontic preparations deal with both undermined during access opening preparation. b. Should be in the middle third of the tooth, both coronal and radicular access, each of which b. The oval is usually centered between the mesial pit mesiodistally and incisal-apically is achieved separately but ultimately flow and the mesial edge of the oblique ridge. c. Is usually oval or rounded together into a single preparation. c. The access opening must be filed labially and d. None of the above a. True palatally to shape and clean the canal properly. 26. The access cavity form of the mandibular b. False d. Preparation of the access should be distal to the second premolar is affected by which 7. How must the endodontic cavity’s mesial marginal ridge. variation in the external anatomy: outline form be shaped and positioned 17. Due to the maxillary first molar a. Smaller lingual inclination of the crown to correctly establish complete access chamber shape: b. More fully developed lingual half of the tooth a. The buccal and lingual cusps should not be c. Both of the above for instrumentation? d. None of the above a. Must have direct access to the apical foramen undermined during access opening preparation b. Positioned from the cavosurface margin to b. The oval is usually centered between the mesial pit 27. For the mandibular first molar, the access apical foramen and the mesial edge of the oblique ridge opening may be slightly square, and its c. Oval in shape c. The access opening must be filed labially and preparation should be distal to the mesial d. Access opening is triangular palatally to shape and clean the canal properly marginal ridge and primarily within the d. Preparation of the access should be distal to the 8. The convenience form: mesial marginal ridge mesial half of the occlusal surface. a. Provides a convenient and accurate preparation and a. True filling of the root canal 18. The shape of the maxillary second molar b. False b. Provides completes authority over the chamber is usually more oval and less 28. The distal orifice of the mandibular enlarging instrument triangular than the maxillary first molar. second molar is less often ribbon-shaped c. Modifies the cavity outline form to establish greater a. True buccolingually; therefore: convenience in placement of intracoronal restorations b. False a. The buccal and lingual walls converge more d. All of the above 19. When four canals are present, the aggressively distally to form a triangle. 9. Why must remaining carious dentin and access cavity preparation of the b. The buccal and lingual walls converge more aggressively mesiodistally to form a rhomboid. defective restorations be removed? maxillary second molar: a. Has an oval shape and is a smaller version of the c. The buccal and lingual walls converge more a. To eliminate as many bacteria as possible from the aggressively mesiodistally to form a triangle. interior tooth access cavity for the maxillary first molar b. Has an oval shape and is widest in the d. The two canals, one mesial and one distal, line up in b. To eliminate the discolored tooth structure that may the buccolingual center of the tooth. ultimately lead to staining of the crown buccolingual dimension c. Both of the above c. Has a triangular shape that is centered between the 29. Investigators in Japan and China found d. None of the above mesial pit and the mesial edge of the oblique ridge a ______incidence of C-shaped root d. Has a rhomboid shape and is a smaller version of the canal systems. 10. When cleansing the cavity, access prepara- access cavity for the maxillary first molar a. 19.1 percent tion should include: 20. The access cavity form of the third molar b. 23 percent a. Removal of purulent fluids can vary greatly, because the tooth typi- c. 31.5 percent b. Removal of hemorrhagic fluids d. 32.7 percent c. Flushing action of debris and dentin chips cally has ______, which would require d. All of the above the access preparation to be anything from 30. A straight line to the canal system that an oval that is widest in the buccolingual ultimately leads to the apex may achieve 11. Due to the possibility of an air embolism, dimension to a rounded triangle similar to optimal results when it is based on necrotic material must be removed from that used for the maxillary second molar. knowledge of the internal morphology the chamber with an air syringe before the a. One to two canals and observance of the principles of radicular instrumentation is begun. b. One to three canals cavity preparation. a. True c. Two to three canals a. True b. False d. Two to four canals b. False www.ineedce.com 7 ANSWER SHEET Guidelines for Access Cavity Preparation in Endodontics

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Requirements for successful completion of the course and to obtain dental continuing education credits: 1) Read the entire course. 2) Complete all information above. 3) Complete answer sheets in either pen or pencil. 4) Mark only one answer for each question. 5) A score of 70% on this test will earn you 4 CE credits. 6) Complete the Course Evaluation below. 7) Make check payable to PennWell Corp.

Mail completed answer sheet to Educational Objectives Academy of Dental Therapeutics and Stomatology, 1. Understand access as the most important phase of nonsurgical root canal treatment A Division of PennWell Corp. 2. Comprehend principles of cavity preparation and proposed guidelines to accurately prepare and fill the radicular P.O. Box 116, Chesterland, OH 44026 or fax to: (440) 845-3447 pulp space 3. Understand the four parts to endodontic coronal cavity preparation—outline form, convenience form, removal of For immediate results, go to www.ineedce.com remaining carious dentin and defective restorations, and cleansing of the cavity and click on the button “Take Tests Online.” Answer sheets can be faxed with credit card payment to 4. Understand the differences in chamber and access shape for each tooth type and protocol to follow when performing (440) 845-3447, (216) 398-7922, or (216) 255-6619. on each Payment of $59.00 is enclosed. (Checks and credit cards are accepted.) Course Evaluation If paying by credit card, please complete the following: MC Visa AmEx Discover Please evaluate this course by responding to the following statements, using a scale of Excellent = 5 to Poor = 0. Acct. Number: ______1. Were the individual course objectives met? Objective #1: Yes No Objective #3: Yes No Exp. Date: ______Objective #2: Yes No Objective #4: Yes No Charges on your statement will show up as PennWell 2. To what extent were the course objectives accomplished overall? 5 4 3 2 1 0

3. Please rate your personal mastery of the course objectives. 5 4 3 2 1 0

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9. Would you participate in a similar program on a different topic? Yes No

10. If any of the continuing education questions were unclear or ambiguous, please list them. ______

11. Was there any subject matter you found confusing? Please describe. ______

12. What additional continuing dental education topics would you like to see? ______AGD Code 074

PLEASE PHOTOCOPY ANSWER SHEET FOR ADDITIONAL PARTICIPANTS.

AUTHOR DISCLAIMER INSTRUCTIONS COURSE CREDITS/COST RECORD KEEPING The authors of this course have no commercial ties with the sponsors or the providers of All questions should have only one answer. Grading of this examination is done All participants scoring at least 70% (answering 21 or more questions correctly) on the PennWell maintains records of your successful completion of any exam. Please contact our the unrestricted educational grant for this course. manually. Participants will receive confirmation of passing by receipt of a verification examination will receive a verification form verifying 4 CE credits. The formal continuing offices for a copy of your continuing education credits report. This report, which will list form. Verification forms will be mailed within two weeks after taking an examination. education program of this sponsor is accepted by the AGD for Fellowship/Mastership all credits earned to date, will be generated and mailed to you within five business days SPONSOR/PROVIDER credit. Please contact PennWell for current term of acceptance. Participants are urged to of receipt. This course was made possible through an unrestricted educational grant. No EDUCATIONAL DISCLAIMER contact their state dental boards for continuing education requirements. PennWell is a manufacturer or third party has had any input into the development of course content. The opinions of efficacy or perceived value of any products or companies mentioned California Provider. The California Provider number is 3274. The cost for courses ranges CANCELLATION/REFUND POLICY All content has been derived from references listed, and or the opinions of clinicians. in this course and expressed herein are those of the author(s) of the course and do not from $49.00 to $110.00. Any participant who is not 100% satisfied with this course can request a full refund by Please direct all questions pertaining to PennWell or the administration of this course to necessarily reflect those of PennWell. contacting PennWell in writing. Machele Galloway, 1421 S. Sheridan Rd., Tulsa, OK 74112 or [email protected]. Many PennWell self-study courses have been approved by the Dental Assisting National Completing a single continuing education course does not provide enough information Board, Inc. (DANB) and can be used by dental assistants who are DANB Certified to meet © 2008 by the Academy of Dental Therapeutics and Stomatology, a division COURSE EVALUATION and PARTICIPANT FEEDBACK to give the participant the feeling that s/he is an expert in the field related to the course DANB’s annual continuing education requirements. To find out if this course or any other of PennWell We encourage participant feedback pertaining to all courses. Please be sure to complete the topic. It is a combination of many educational courses and clinical experience that PennWell course has been approved by DANB, please contact DANB’s Recertification survey included with the course. Please e-mail all questions to: [email protected]. allows the participant to develop skills and expertise. Department at 1-800-FOR-DANB, ext. 445.

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