Exam 1 2017, questions and answers PDF

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ENDODONTICS AND PERIODONTOLOGY 1. The following are requirements of an ideal root canal filling materials: I. should not be impervious to moisture II. should not shrink III. should not stain tooth structure IV. should be radiopaque A. I, II & III B. I, III & IV C. II,...

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ENDODONTICS AND PERIODONTOLOGY 1. The following are requirements of an ideal root canal filling materials: I. should not be impervious to moisture II. should not shrink III. should not stain tooth structure IV. should be radiopaque A. I, II & III B. I, III & IV C. II, III & IV D. I, II, III & IV

E. I & III only

2. Gutta percha as a root canal sealer: A. can be condensed and well adapted to the irregularities and contours of the canal walls B. is rigid and easily adapted to canals smaller than size 30 C. cannot be displaced by pressure therefore, overfilling is not a hazard D. relatively insoluble and difficult to remove from the canal when necessary E. has an adhesive property or quality, therefore, use of sealers is optional 3. Body defenses that facilitates disinfection of root canals: A. phagocytic cells C. antibiotics B. antibodies D. both A & B

E. both B & C

4. Internal resorption is detected in a vital, asymptomatic tooth. Treatment of choice is to: A. extract the tooth B. perform a pulpotomy C. keep the tooth under observation D. remove the pulp and proceed with endodontic treatment at this time E. none of the above 5. The action used for placing a K-type file into a canal should resemble: A. an up-and-down motion B. a straight apical pressure C. complete rotation of the instrument with pressure directed apically D. a clockwise-counterclockwise motion with pressure directed apically E. none of the above. 6. Which condition is contraindicated for endodontic treatment? A. carious exposure with pulpal involvement B. a non-functional tooth with no future strategic importance C. necrotic tooth with internal resorption D. horizontal crown fracture above the gingival margin E. none of the above. 7. Which of the following may be used to disinfect gutta percha points: A. boiling C. chemical solutions B. autoclave D. flame sterilization E. dry heart sterilization 8. Used as an intertreatment dressing material: A. fermin B. Cavit C. NaoCL

D. CMCP

E. EDTA

9. In which of the following pathologic conditions would a single-rooted teeth be expected to respond to heat, cold and electric pulp tester? A. apical cyst C. chronic apical periodontitis B. acute apical abscess D. suppurative apical periodontitis E. Periapical cemental dysplasia (cementoma) 10. Which of the following is characteristic of sensory fibers of the pulp? A. They can selectively differentiate thermal stimuli

B. They have special neuronal endings that are specific for proprioception

C. They are non-selective to all stimuli indicating only pain when the threshold has been exceeded. D. None of the above. 11. Common compacting instrument: A. file B. spreader

C. plugger

D. lentulofiller

12. Characterized as the 3-dimensional filling of the entire root canal system is as close to the DCJ as possible: A. master cone B. obturation C. mechanical preparation D. apical cone 13. A 3-dimensionally well-filled root canal system: A. prevents percolation of periapical exudates into the root space B. maximizes the amount of sealer and minimizes the cone material C. is independent of the endodontic cavity design D. is dependent upon the use of intracanal medications to sterilize the canal E. none of the above 14. Desired periapical tissue responses after endodontic therapy on a tooth with a periapical lesion include: I. regeneration of dentin II. regeneration of alveolar bone III. deposition of apical cementum IV. re-establishment of the periodontal ligament A. I, II & IV B. I & IV only C. II & IV only D. II, III & IV E. III & IV only 15. Which of the following is least likely to cause discoloration of a tooth with a necrotic pulp? A. decomposition of necrotic tissue B. hemolysis of unremoved blood cells C. failure to include pulp horns in a coronal access D. frequent ingestion of heavy doses of tetracycline E. use of a root canal sealer that contains precipitated silver 16. Biomechanical preparation of the root canal is necessary to: A. straighten minor canal curvature B. prevent post operative discoloration C. remove areas that can retain bacteria and debris D. create a space easy to obliterate E. all of the above 17. Ideal root canal medication and dressing: A. carbolic acid C. oil of cloves E. formocresol B. penicillin preparation D. Camphorated monochlorophenol 18. Ideal root canal obturant: A. zinc oxide eugenol cement B. gutta percha

C. silver points D. both A & B

E. all of the above

19. In which of the following is one-visit root canal treatment not recommended? A. The pulp is necrotic and not symptomatic B. The pulp is necrotic and symptomatic. C. The pulp is necrotic and there is a draining sinus tract. D. The pulp is vital and symptomatic. E. None of the above. 20. The result of RCT in establishing patency is: A. It prevents procedural errors, such as canal blockage and transportation. B. It causes irritation of the periodontal attachment apparatus and increased post operative pain.

C. It enlarges the apical terminus and increases the potential for extrusion of obturating material. D. It requires insertion of a file 1.0 to 2.0 mm beyond the canal terminus. 21. The mandibular, 2nd molar should be restored with crown after RCT for which of the following reasons? A. The pulp chamber is relatively large in comparison to the crown, making the tooth susceptible to fracture. B. The tooth is in close to the insertion of the muscle of mastication, and the percentage of preexisting fractures is high. C. There is a tendency for the buccal cusps to shear off under occlusal loading. D. Providing a post can be placed in the distal root to strengthen the root. 22. A problem with nickel-and-titanium (NiTi) spreaders is which of the following? A. Tendency to buckle under compaction pressure. B. Tendency to break during condensation. C. Creation of greater wedging forces, leading to root fracture. D. They do not penetrate as deeply as stainless spreaders under equal force. 23. A common gutta percha solvent: A. alcohol C. beachwood creosote B. chloroform D. camphorated monochlorophenol E. sodium hypochlorite 24. Moderate extrusion of obturating materials beyond the apex is undesirable because of which of the following? A. There is more likelihood of postoperative discomfort. B. Sealer and gutta-percha cause a severe, inflammatory reaction in periradicular tissue. C. The prognosis is poorer. D. All of the above. E. both A & B only 25. Piezoelectric, ultrasonic devices differs from magneto-strictive devices in which of the following? A. The piezoelectric unit transfers more energy to the files. B. The piezoelectric unit produces heat that requires a coolant. C. The piezoelectric unit uses a RispiSonic, SharperSonic, and TrioSonic file system D. The piezoelectric unit vibrates at 2 to 3 kHz. 26. Once the root canal is obturated, what usually happens to the organisms that had previously entered periapical tissues from the canal? A. They persist and stimulate formulation of a granuloma. B. They are eliminated by the natural defenses of the body. C. They re-enter and reinfect the sterile canal unless periapical surgery is performed. D. They will have been eliminated by various medicaments that were used in the root canal. 27. Erratic and inconsistent results from electric pulp testing may be caused by: 1. saliva on the tooth 2. secondary dentin obliterating the pulp chamber 3. multiple canals presenting various stages of pulp pathosis A. 1 & 2 B. 1 & 3 C. 2 & 3 D. 1 only E. 1,2 & 3 28. Sodium hypochlorite may be used effectively as: 1. an antimicrobial agent 2. a tissue solvent 3. a chelating agent 4. an anodyne dressing A. 1, 2 & 3 B. 1 & 2 C. 2, 3 & 4

D. 2 & 3

29. The most effective means to reduce root canal microbes is: A. systemic medication

E. 1 & 3

B. complete debridement of the root canal C. intracanal medication with a non-specific drug D. intracanal medication with multiple antibiotic preparations. 30. The primary function of a root canal sealer is to: A. prevent discoloration B. seal dentinal tubules C. stimulate healing in the apical region D. medicate the canal to eliminate remaining bacteria E. fill the space between the solid cone material and the pulp canal wall. 30. Perforation on the mesial in the cervical third of the root of a maxillary first premolar is a common error in performing an endodontic procedure because: A. the crown tipped distally. B. The root tends to curve distally C. The entire tooth tends to tip distally D. The bur tends to be directed mesially E. A concavity on the mesial root frequently exists. 31. A healthy 8-year old child has fractured permanent central incisor. The pulp is widely exposed and vital. From radiographs, root ends appear incompletely calcified. The recommended procedure is to: A. cap the pulp C. perform a pulpotomy B. extract the tooth D. remove the entire pulp. 32. The action of calcium hydroxide in promoting formation of an apical calcified barrier in a tooth with an open apex and a necrotic pulp is probably best explained by: A. creation of a zone of liquefaction necrosis at the apex B. creation of a zone of coagulation necrosis at the apex C. creation of an environment that promotes hard tissue deposition D. calcium ions from the canal dressing precipitating apically to form an apical bridge. 33. The least important factor influencing the pathogenicity of endodontic flora is: A. Microbial interaction. B. Endotoxins released after bacterial death. C. Exotoxins released by living bacteria D. Enzymes produced by bacteria. 34. Which of the following statements is accurate regarding gutta-percha points? A. They contain 40% to 50% pure gutta-percha. B. They adhere to dentin when compacted C. They can be heat sterilized. D. They are not compressible. 35. Retreatment has the most favorable prognosis during which of the following? A. When the cause of failure is identified and is correctable. B. When the patient is asymptomatic. C. When gutta-percha was used instead of paste. D. When a surgical microscope is used. 36. Which of the following teeth is most likely to exhibit C-shaped morphology? A. Maxillary first premolar C. Mandibular first premolar B. Maxillary first molar D. Mandibular first molar. 37. Which of the following are indications for surgical endodontic intervention? 1. a non-negotiable canal with periapical pathosis 2. a sinus tract that persists after repeated treatment 3. periapical pathosis in a tooth with a post and core retained crown. A. 1 & 2 B. 1 & 3 C. 2 & 3 D. 1,2 & 3 E. 3 only

38. Histologically, the normal dental pulp most closely resembles: A. nervous tissue D. loose connective tissue B. endothelial tissue E. dense connective tissue C. granulomatous tissue 39. One objective of root canal obturation is to develop a fluid tight seal. Another objective is to create a favorable biologic environment for the process of tissue healing. A. Both statements are TRUE. B. Both statements are FALSE C. The first statement is TRUE, the second is FALSE D. The first statement is FALSE, the second is TRUE. 40. A dentist restored an endodontically treated tooth with a cast post-and-core and a metal ceramic crown. Tree months later, the patient calls and complains of pain, especially on biting. Tooth mobility is normal, as are the radiographs. The most probable cause of pain is: A. a loose crown C. a vertical root fracture B. psychosomatic D. a premature eccentric contact 41. Which of the following perforations has the poorest prognosis? A. Perforation near the apex B. Perforation into the furca C. Perforation through the crown D. Perforation at the DEJ E. perforation at the CEJ 42. Which of the following is used to bleach a discolored, endodontically treated tooth? A. Ether C. Sodium bicarbonate B. Chloroform D. Sodium hypochlorite E. Hydrogen peroxide 43. The most important principle governing the location and outline of the lingual or occlusal opening into the pulp chamber is: A. preservation of tooth structure. B. Direct access along straight lines. C. Complete removal of the roof of the pulp chamber D. Removal of all caries and defective restorative material. 44. Endodontic therapy is contraindicated for a single rooted tooth that has: A. discoloration B. an acute apical abscess C. a chronic abscess and a draining sinus tract D. a horizontal fracture of the apical third of the root. E. A vertical fracture of the root and an associated deep periodontal defect 45. A negative response to the electric pulp tester immediately after a severe luxation of a tooth indicates that the: A. pulp is inflamed B. electric pulp tester is giving a false reading C. pulp is necrotic and should be removed D. blood supply is interrupted, and the negative response may be temporary E. neural transmission is interrupted ,and the negative response may be temporary. 46. In treating a root canal before obturation, the most important consideration is: A. general health of the patient B. cleaning and shaping of the canal C. efficacy of the irrigating solution D. amount and concentration of medication used. E. Sterilization of the canal as evidenced by negative cultures...