Endo MCQS

1. 1. If the maxillary first molar is found to have 4 canals, the 4th canal is most found : a. In the disto-buccal root b. In the mesio-buccal root c. In the palatal root d. All of the above 2. Step back or backfilling means; to instrument the root canal to the full length predetermined working length. a. True b. False 3. The " Working Length" of a tooth refers to: a. The total length of a tooth from crown tip to root tip. b. The measured length of a radiograph of the tooth. c. The distance between a reference point on the crown and the apical limit of the tooth. d. None of the above. 4. A central incisor diagnostic (pre operative) radiograph image measures 25mm from the incisal edge to the root apex. The estimated (initial) working length is : a. 21mm b. 25mm c. 23mm d. 27mm 5. You are taking a working length radiograph of a normally positioned maxillary premolar with 2 equal length roots. In the mesial shift (relative to the "normal" diagnostic radiograph) the palatal root apex in relation to the zygomatic process "moves" to the: a. Occlusal b. Apical c. Distal d. Mesial 6. The main objective of root canal obturation is to allow an ingress of tissue fluid exudates into the root canal space. a. True b. False 7. Gutta Percha points consist mostly of: a. Gutta Percha b. Zinc oxide c. Zinc phosphate

d. Glass ionomer 8. Requirements of an ideal root canal filling material include the following except: a. Dimensional stability: no shrinkage after insertion b. Non-irritant to periapical tissue c. Radiolucent when viewed by radiograph d. Easy to remove from the canal if necessary 9. Leaving the tooth open between appointment during root canal therapy could lead to: a. Healing of the periapical lesion b. Bacterial contamination of the root canal system c. Neither A nor B 10. In instrumentation you should use a curved file. a. True b. False 11. Root canal sealer cement is used mainly to: a. Create radioopacity b. Fill in voids and canal irrigularities c. Disinfect the root canal system d. Strengthen the filling 12. An irrigating solution is used during root canal therapy to: a. Lubricate the canal b. Flush out debris c. Aid in cleaning the canal d. All of the above e. None of the above 13. Which of the following are explanation as to why the initial gutta percha master cone will not completely go to full working length even though it is same number as the last enlarging instrument used? a. Debris remain in the canal b. A ledge exists in the canal upon which the point is catching c. None of the above d. All of the above 14. You started instrumenting the root canal until you reached the master apical file size #30 K, a series of files are used after the MAF with 1mm short of each other. The technique is called: a. Recapitulation b. Step-back c. Tug-back

d. None of the above 15. Which of the following is an error occurred during obturation of the root canal? a. Ledge formation b. Voids c. Filling lateral canal d. Broken instrument 16. The "TUGBACK" of the master gutta percha cone refers to: a. The tensile strength of the gutta percha cone b. The retention of the cone in the apical portion of the canal c. The retention of the cone in the coronal half of the canal d. None of the above 17. The following are common errors can be created during access opining process a. Perforation of the crown or the furcation area b. Making the access opining through the distal surface of the tooth c. Complete removal of caries d. A, B, and D 18. Limitation of radiograph includes a. Only 2 dimensions are shown on a single film b. Various states of pulpal and periradicular pathosis are indistinguishable in the xray shadow c. Lesions of the cortical bone are likely to go undetected d. A and B e. All of the above 19. Objectives of rubber dam: a. Patient protection b. Facilitate and increase efficiency c. Minimize cross-infection d. Legal consideration e. All of the above 20. In giving local anesthesia in endodontics: a. Maxilla bone is less dense than mandible b. Buccal infiltrations or supraperiosteal injection are sufficient to obtain pulpal anesthesia in maxilla and mandible c. Block anesthesia is more effective in mandible d. A and C e. All of the above 21. Mesiobuccal root of upper 1st molar is innervated by:

a. PSA nerve b. MSA or ASA nerve c. None of the above 22. In inferior alveolar nerve block a. Pulpal anesthesia obtained from central incisor to 3rd molar b. Usually results in lingual nerve block as well c. Anesthetize buccal soft tissues of molar region d. All of the above e. A and B 23. Purpose of the access cavity a. Access to the end of the root b. Controlled instrument placement c. Allow removal of debris d. Allow introduction of materials and instruments e. All of the above 24. In endodontic access preparation of maxillary anterior teeth, all statements are true except: a. Entrance is always gained through the lingual surface b. Initial entrance is prepared a right angle to the long axis of the tooth c. No. 1 or 2 round bur must be used internally to open the coronal part d. The preliminary cavity outline is triangular in shape 25. If there are 2 canals in the distal root of mandibular 1st molar they usually: a. Each have their own apical foramen b. Begin as a single canal and bifurcate in the apical half c. Begin as 2 canals and join and exit as one d. Are smaller than the mesial canal 26. A root that seldom contains 2 canals is the: a. Distobuccal root of the maxillary molar b. Mandibular central incisor c. Maxillary second premolar d. Distal root of the mandibular molar 27. The access outline form a. Should be somewhat smaller than the form created by connecting thr root orifices b. Reflects the shape of the crown of the tooth c. Should extend onto the tooth's marginal ridges d. All of the above 28. Entry into maxillary central incisor is made a. Below (apical to) the cingulum in the direction of the long axis of the tooth

b. Just coronal to the cingulum in the direction of the long axis of the tooth c. To include the marginal ridges d. With a slow speed bur 29. The maxillary 1st premolar a. Canal orifices lie beneath the central groove b. Is similar in length to the maxillary canine c. May have one, two, or three canals d. All of the above e. None of the above 30. Nerve fibers of the dental pulp are classified according to their: a. Function b. Diameter c. Conduction velocity d. All of the above 31. The diameter of the A-delta sensory nerve fiber of the pulp is: a. 5-12 μm b. 5-12 cm c. 1-5kg d. 1-5 μm 32. The fluid movement in dentinal tubles (Hydrodynamic theory) is of dentin sensitivity (pain). It was introduced by: a. Brannstrom 1966 b. Byers 1980 c. Kim 1983 d. None of the above 33. The following theories were suggested to explain the dental pain: a. There is a direct stimulation of nerve endings in dentin b. The odontoblast do not acts as a receptor cell c. The hydrodynamic theory d. A and C only e. All of the above 34. Most of nerves of the pulp fall into 2 main categories A and C has the following characteristics : a. Myelinated b. Usually associated with tissue injury c. Has a diameter of 1-5 mm d. All of the above 35. The diameter of the C- sensory nerve fiber of the pulp is : a. 1-5μm b. 5-12μm

c. 0.4-1 cm d. 0.4-1μm 36. The pain characteristics of A-fibers is: a. Dull, burning b. Mild c. Sharp and pricking d. None of the above 37. Pulpal blood flow is usually regulated by: a. Amoxicillin 250mg b. Panadol 500mg c. Arterio-venous anastomosis d. None of the above 38. Capiliary blood flow in the coronal portion of the dental pulp is double root portion. a. True b. False 39. The detailed network arrangement of pulpal microvascular in … viscosity synthetic resin "Corrosion Resin Cast" and scanning electromicroscop was first studied by: a. Saunders 1957 b. Takahashi 1982 c. Avery 1970 d. None of the above 40. The following structural elements are found in the pulp: a. Fibroblast and odontoblasts b. Undifferentiated mesenchymal cells and ameloblasts c. Fibers, ground substances and osteoclasts d. All of the above 41. Calcification can occur in the dental pulp as: a. Abnormal irregular dentin production b. Free, attached and embedded denticles c. All of the above d. None of the above 42. The first beginning of dental papilla is seen at the : a. 8th week of fetal life of cap stage b. 8th week of fetal life of bell stage c. Dental papilla has nothing to do with tooth development d. All of the above

43. Dentin is composed of: a. 7% inorganic material b. 17% inorganic material c. 70% organic material d. 70% inorganic material 44. Which statement is correct ? a. Tissue engineering is the field of functional restoration of tissue structural physiology for impaired or damaged tissue because of cancer, diseases or trauma. b. Tissue engineering is the field of functional endodontic of tissue structural microbiology for impaired or damaged tissue because of cancer, diseases or trauma. 45. The key elements of tissue engineering are: a. Bacterial cells, morphogens, and a scaffold of extracellular matrix b. Stem cells, morphogens, and a scaffold of extracellular matrix c. Blasma cells, morphogens, and a scaffold of intracellular matrix d. All of the above 46. The success rate of endodontic therapy has been found to be _________ in studies on teeth with no periapical periodontitis at the time of treatment. a. 35% - 45% b. 55% - 67% c. 78% - 87% d. 91% - 98% 47. Sodium hypochlorite ___________ a. Is an effective microcode b. Effectively dissolve residual tissue c. Can be used without any concern for its extrusion through the apex d. A and B 48. The effectiveness of irrigation and the resulting canal cleanliness are attributed primarily on _ a. The quality of the microbial control b. The quality of the coronal seal c. The quality of canal preparation d. All of the above 49. Root canal should be cleaned, shaped, and obturated to the constriction for each of the following reasons except : a. The constriction is the narrowest diameter of the canal. b. Lateral and accessory canals are common in the apical 1 to 2 mm of the canal. c. The clinician can easily identify the constriction . d. Obturating materials are maintained within the root canal system.

50. Siqueira et al found sufficient evidence for the effectiveness of sonic and ultrasonic in root canal preparation. a. True b. False 51. Preparing the curved canal in multiple planes: a. Permits preservation the natural curvatures b. Increase the risk of furcal perforation c. Requires Gates-Glidden drills d. Accomplished by maintaining apical patency 52. The most common pathway for microbes and microbial products to reach the pulp is: a. Direct through a carious lesion b. Apical extension of periodontal disease c. Pulpal inflammation and anachoresis d. From adjoining necrotic pulp and periapical lesions 53. A cellulites between the superficial fascia requires treatment that include a. Vigorous antibiotic and supportive measures b. Endotoxins and drainage c. Antibiotic and drainage d. Rest , fluid and supportive measures 54. In order to control the incidence of post-treatment flare ups of previous periapical area, it is recommended : a. Use prophylactic antibiotic coverage b. Instrumentation within the root canal system c. Antibiotic coverage if symptoms develop d. The use of antibiotic sensitivity teasting 55. Pulpal and periradicular pathosis results primarily from: a. Traumatic injury b. Immunological reaction c. Bacterial invasion d. Toxicity of dental material 56. The major component of the pulp is: a. Collagen b. Cells c. Support structures (vessels and nerves) d. Water 57. Early pulpal infection exhibits: a. Nonspecific inflammatory response b. Specific inflammatory response c. Both Specific and Nonspecific inflammatory response

d. Acute inflammatory response 58. In the inflammatory process, which of the following cell type acts as a phagocyte a. Macrophage and neutrophils b. Lymphocytes and neutrophils c. Plasma cells and basophils d. Macrophages and lymphocytes 59. Apical true cyst a. Epithelial lined cavity attached to the root end b. Epithelial lined cavity free of the root end c. Connective lined cavity attached to the root end d. Connective lined cavity free of the root end 60. The following periapical diagnosis, which would most likely contain pus a. Necrosis b. Supportive apical periodontitis c. Apical cyst d. Chronic apical periodontitis e. Acute apical periodontitis 61. Chronic apical periodontitis (Granuloma) present a histological consistent with: a. Infection b. Early cyst formation c. Healing d. Immune response 62. Hard tissue deposition in pulp spaces of teeth with root fracture is a. Dentin b. Cementum c. Osseous tissue d. A and B 63. According to Ricucci et al (JOE; April 2009) in their evaluation of teeth with apical periodontitis , the primary cause of endodontic treatment a. Intraradicular infection in the form of biofilm b. Extraradicular bacteria in sessile form c. Extraredicular bacteria in planktonic form d. Viruses particularly EBV 64. Hakki et al (JOE; April 2009) investigated the effect of MTA on the cell survival, gene expression and found that: a. MTA induced lesser biomineralization b. MTA did not have negative effect on the viability and morphology of cementoblasts

c. MTA exhibited cytotoxicity in smaller concentrations d. MTA is not considered as bio-inductive 65. According to Hammad et al (JOE; April 2009) in investigating the 3D evaluation of root canal obturation, a. Gutta flow showed less gaps compared to the other materials b. Real seal showed the leas voids compared to the other materials c. Endorez showed better adaptability to the root canal walls d. None of the materials showed gap or voids free obturation 66. According to Komabayashi et al (JOE; Feb 2009) calcium hydroxide particles size were: a. Larger than the dentinal tubles b. Smaller than the dentinal tubles c. The size as the dentinal tubules d. Not compatible with the dentinal tubules 67. The ideal pain reliever combination is to alternate between: a. Ibuprofen and aspirin b. Ibuprofen and acetaminophen c. Ibuprofen and opioids 68. Maximal dose of ibuprofen per day is: a. 2 grams b. 3.2 grams c. 6 grams 69. A sinus tract near the gingival margin may indicate: a. Periodontal pocket b. Opening of apical abscess sinus tract c. Vertical root fracture 70. Pulp necrosis is most likely to occur after which of the following: a. Midroot fracture b. Intrusive luxation c. Concussion d. Complicated crown fracture 71. Which medium of storage for an avulsed tooth is best for prolong --a. Hanks balances salt solution b. Milk c. Distilled water d. Saliva 72. Occlusal reduction is indicated in cases with: a. Irreversible pulpitis b. Irreversible pulpitis with acute apical periodontitis c. Chronic apical abscess

d. All of the above 73. The best treatment of irreversible pulpitis at the initial visit a. Pulpotomy b. Complete removal of the pulp c. Single visit endodontics d. Occlusal reduction to relieve pain e. A and D 74. …. ….. prognostic factor in fractured crown is: a. Subgingival extension b. Degree of fracture c. Pulp involvement d. All of the above 75. The direction of cracking in posterior teeth is: a. Occlusogingival b. Buccolingual c. Mesiodistal d. All of the above 76. C+ files are used for : a. Negotiation of curved canals b. Prepare calcified canals c. Prepare narrow curvedcanal d. All of the above 77. The differential diagnosis between apical graneuluma and cyst a. The size of the lesion in the radiograph b. Computed tomography scan c. Presence of hard intraoral swelling d. All of the above 78. Management of cases with acute apical periodontitis and diffused swelling a. I D and antibiotic b. Canal debridment, Ca(OH)2 dressing and antibiotic and I D c. Canal debridment, Ca(OH)2 dressing and antibiotic d. I D only to decrease pain 79. The best antibiotic prescribed in cases of cellulites a. Amoxicillin b. Clyndamicine c. Mitronidazol d. Erythromycin e. None of the above 80. The success rate of root canal treatment with apical periodontitis a. 62%

b. 80% c. 40% 81. The success rate of root canal treated teeth with vital pulp give more than 95%, while presence of apical periodontitis decrease the rate by: a. 30% b. 10 – 25% c. No difference 82. Periapical lesions of size range 5 – 8 mm heal completely within: a. 3 months b. 5 months c. 8 months d. 1 year 83. The time is taken by mandibular nerve block for complete anesthesia is: a. 15 min b. 10 min c. 5 min 84. Teeth with irreversible pulpitis and acute apical periodontitis should be monitored every: a. Week b. 8 hours c. 24 to 48 hr 85. Premedication with NSAIDs in symptomatic irreversible pulpitis is done to: a. Relieve pain b. Raise the pain threshold c. Decrease postoperative pain 86. Which of the following is not a step as part of the technique for shallow (partial) Cevk pulpotomy? a. Rubber dam isolation b. Pulp tissue removed to about 2 mm below the exposure c. Use of a large round carbide but in the slow – speed handpiece to remove tissue. d. Restoration of the cavity with a hard setting cement 87. What should be considered that determines the treatment of an intrusive luxation injury? a. Depth of intrusion b. Stage of root development c. Availability of adjacent teeth for stabilization d. Amount of soft tissue injury 88. Which type of medication is indicated for patterns with avulsed teeth? a. Narcotic analgesic

b. Steroid c. Tetanus booster if more than 5 years since last administered d. All of the above 89. What additional treatment should be used on the root surface if an avulsed tooth replanted after more than 1 hour after avulsion? a. Thorough scrubbing with antimicrobial soap for disinfection b. Scaling of the root surface c. Soaking the tooth in 2.4% doxycycline for 5 t0 20 minutes d. Soaking the tooth in 2.4% solution sodium fluoride for 5 to 20 minutes 90. If several teeth are out of alignment after trauma, the most reasonable explanation is which of the following: a. Luxation b. Subluxation c. Alveolar fracture d. Root fracture 91. The restorability of a tooth depends on the following except a. Structure integrity b. Remaining tooth structure c. Number of roots d. Level of surrounding bone and amount of periodontal support 92. The hollow tube theory states that: a. Inflammation persists at the opened implanted tubes . b. Inflammation persists at the median portions of the implanted tubes. c. Inflammation is absent at the opened end of the implanted tubes if they are sterile. d. Necrosis is evident around both ends. 93. A 17 years old patient came to your office right after receiving trauma on his face. After examination, it was recorded that tooth #11 was not responding to EPT. The right management for this case is : a. Pulpectomy and splinting if the tooth is mobile b. Pulpotomy and splinting if the tooth is mobile c. Splinting the tooth if mobile and seeing the patient after 2 weeks d. None of the above 94. When is root canal treatment is indicated in a mature avulsed, replanted tooth? a. At the time of replantation b. Within 7 to 10 days after replantation c. After 3 months if there is no response to pulp testing d. When periapical pathosis noted 95. The purpose of splinting a luxated tooth is to :

a. Prevent resorption b. Prevent pulpal calcification c. Allow pulpal recovery d. Allow re-organization of periodontal ligament fibers 96. Microseal is an obturation technique characterized as : a. Warm lateral b. Warm vertical c. Cold vertical d. Combination of warm and cold 97. Resilion has been investigated thoroughly for the existence of mono block but little research has been carried on its : a. Estrogenic potential due to its monomer leach out b. Capability of providing apical seal c. Capability of providing coronal seal d. Adaptation to the root canal walls 98. Alpha phase GP is : a. The natural occurring form b. Stick more flowable form c. Amorphous form 99. In preparation for obturation using system B, the selected master cone should fits: a. At the full working length b. Short of the working length by 2 mm c. Be 2% taper d. Should be greater taper cone 100. The NiTi end of the Buchanan hand plugger number one s is approximately: a. 0.5 mm in diameter b. 1.0 mm in diameter c. 1.2 mm in diameter d. 1.5 mm in diameter