Tooth Morphology And Access Cavity Preparation MCQs (Endodontic MCQs)

Tooth Morphology And Access Cavity Preparation MCQs _ Endodontic MCQs

Tooth Morphology And Access Cavity Preparation MCQs _ Endodontic MCQs

1. Which of the following statements about lateral accessory canals is correct:
   A. When present, they are a source of collateral circulation for the dental pulp tissue.
   B. They are formed by residual cells of Hertwigs epithelial root sheath.
   C. Maxillary molars have the highest incidence of canals involving the pulp chamber floor and the furcation surface.
   D. A relationship exists between the occurrence of furcation canals and the presence of calcification and pulp stones in the pulp chamber.
   E. Approximately 75 are found in the apical one third of the root.
   
2. A type II canal is defined as:
   A. A single canal with one portal of exit at the apex.
   B. Two canals in the chamber that join and have a common portal of exit at the apex.
   C. Two canals in the chamber, each with a portal of exit at the apex.
   D. Two canals in the chamber that merge in the body of the root and divide short of the apex to exit as two distinct canals.
   E. A single canal that divides in the root to exit as two distinct canals at the apex.
   
3. The practitioner would consider all but one of the following factors when evaluating the canal anatomy of the root canal system in a 26-year-old woman who requires root canal treatment of the mandibular right first premolar. Which is the exception
   A. Age
   B. Gender
   C. Ethnicity
   D. Angled radiographs
   E. Microscopy
   
4. When two canals are present in a single root and join
   A. The buccal canal generally is the one with direct access to the apex.
   B. Both canals should be prepared to the apex.
   C. Rotary nickel-titanium instrumentation is indicated to ensure that the proper shape is developed.
   D. The configuration is classified as type IV.
   
5. Which of the following statements about the apical anatomy is correct
   A. The location of the apical constriction and the cementodentinal junction are the same in approximately 75 of canals.
   B. The cementodentinal junction is located at the apical foramen.
   C. The apical constriction usually is located 0.5 to 1.5mm short of the apical foramen.
   D. The apical foramen remains static after tooth eruption.
   E. Regardless of the number of accessory canals present, a main apical foramen can be identified.
   
6. Which of the following statements about the apical anatomy of the maxillary anterior teeth is correct:
   A. The apical foramen coincides with the apex in approximately 85 of cases.
   B. The apical constriction mesiodistal diameter generally exceeds the labiolingual diameter.
   C. The labiolingual diameter of the apical constriction generally exceeds the mesiodistal diameter.
   D. When the foramen deviates from the root apex, it usually does so in a mesiolingual direction.
   E. Accessory canals are a rare finding.
   
7. Prognosis studies indicate that for teeth with pulp necrosis
   A. The success rate was higher when root canal treatment terminated at or within 2mm of the radiographic apex.
   B. The success rate was higher when root canal treatment terminated at or within 3mm of the radiographic apex.
   C. The success rate was highest with obturation at the radiographic apex or with extrusion.
   D. Root canal treatment should terminate at the cementodentinal junction.
   E. Termination more than 3mm short of the radiographic apex carries a poorer prognosis than that for extension of the obturation beyond the apical constriction.
   
8. Which of the following statements about assessment (gauging) of the apical canal diameter is correct:
   A. Small hand files can accurately assess the diameter, because the canal configuration in the apical portion is generally round.
   B. The canal diameter generally is larger than the diameter of the instruments used in gauging.
   C. Accuracy in the maxillary first molar is greatest in the main mesiobuccal canal.
   D. Placing small instruments to the corrected working length until initial binding occurs determines the maximum-size file to be used at that length.
   
9. All of the following statements about access openings in maxillary central incisors are correct except one. Which is the exception
   A. The access is triangular in young people but becomes oval in older individuals.
   B. A lingual shoulder extends several millimeters apical to the orifice and restricts cleaning of the canal.
   C. Defective restorations should be removed before an opening into the pulp chamber is made.
   D. Access through an existing crown may be difficult because of the loss of anatomic landmarks.
   E. Ultrasonic tips should be used to open into the chamber after a round bur has been used to penetrate the enamel.
   
10. All of the following statements about access openings in maxillary first molars are correct except one. Which is the exception:
    A. The mesiobuccal canal is located mesial to the mesial cusp tip.
    B. The distal extension should be mesial to the oblique ridge.
    C. Initial penetration into the chamber is accomplished toward the palatal canal orifice.
    D. The canal orifices are always located at the junction of the chamber walls and floor.
    E. The orifices are located at the angles of the floor-wall junction.
    
11. All of the following statements about access openings in mandibular molars are correct except one. Which is the exception:
    A. The orifices for all canals generally are found in the mesial two thirds of the crown
    B. When two separate distal roots are present, the distolingual root is smaller and
    often curves buccally.
    C. A C-shaped canal is a variation of molars with fused roots.
    D. The incidence of C-shaped canals is higher in Japanese, Chinese, Lebanese, and Korean patients.
    E. A middle mesial canal is present in less than 1 of cases.
    
12. By varying the radiographic angle 20, canal morphology can be correctly identified in each of the following tooth groups except one. Which is the exception:
    A. Maxillary first premolars
    B. Maxillary second premolars
    C. Mandibular first premolars
    D. Mandibular second premolars
    
13. Which of the following statements about the fast break is correct
    A. A radiographic fast break identifies 95 of canals that bifurcate.
    B. One third of canals that bifurcate do not appear as fast breaks on the radiograph.
    C. A radiographic fast break indicates calcific metamorphosis.
    D. The term fast break is used for roots with dilacerations greater than 60 degrees.
    
14. Which of the following statements about furcation canals in molars is correct:
    A. The presence of accessory canals correlates with the presence of pulp calcification.
    B. Maxillary molars have the highest incidence of foramina involving the pulp chamber floor and the furcation surface.
    C. Radiographs frequently indicate the presence of furcation canals.
    D. Pulp necrosis and the presence of furcation canals may account for primary endodontic lesions
    
15. Which of the following tooth groups may demonstrate all eight canal configurations
    A. Maxillary first premolars
    B. Maxillary second premolars
    C. Maxillary first molars
    D. Mandibular first premolars
    E. Mandibular second premolars
    
16. Isthmi in the mesiobuccal root of maxillary molars
    A. Are found most often in the apical 3 to 5mm
    B. Are located coronally near the orifice and extend apically for 3 to 5mm
    C. Generally are complete, although partial isthmi can occur
    D. Have a uniform morphologic shape resembling a ribbon
    
17. Which of the following burs is recommended for making an access opening through an existing metal crown:
    A. Round carbide burs (sizes 2, 4, and 6)
    B. Carbide fissure burs
    C. Mueller burs
    D. LN bur
    E. Transmetal bur
    
18. If straight-line access is not achieved upon placement of a small file to the corrected working length in a mandibular incisor, the clinician should:
    A. Extend the access to the incisal edge
    B. Reevaluate the adequacy of lingual shoulder removal
    C. Use a facial access approach
    D. Prebend the instruments during cleaning and shaping procedures
    
19. The starting point for access preparation of first mandibular premolars is
    A. Midway between the mesial and distal marginal ridges in the central groove
    B. Near the buccal cusp tip because of the lingual constriction and inclination of the tooth
    C. Halfway up the incline plane of the buccal cusp
    D. Midway between the mesial and distal marginal ridges one third the distance up the buccal incline plane
    
20. The cross sectional shape of the maxillary first premolar in the coronal portion of the root at the cementoenamel junction:
    A. Demonstrates two separate roots
    B. Resembles a kidney bean, with the concavity on the mesial surface
    C. Has a broad mesiodistal dimension compared with the buccolingual dimension
    D. Resembles a kidney bean, with the concavity on the distal surface.
    
21. A maxillary central incisor with calcific metamorphosis requires endodontic treatment. During access preparation, the canal is not evident clinically, and the preparation is 4mm apical to the cementoenamel junction. Which of the following statements about treatment of this case is correct:
    A. The greatest risk of perforation is on the lingual surface as the preparation is extended.
    B. The canal will not be negotiated as calcification proceeds from the apical region coronally.
    C. Removal of the rubber dam and exposing radiographs may help locate the canal.
    D. The access should be extended using an extended 4 round bur in the high-speed handpiece.
    
22. A perforation during access preparation is more likely in which area:
    A. Maxillary premolar on the mesial aspect at the cementoenamel junction
    B. Mandibular molar on the distal aspect
    C. Maxillary anterior on the lingual aspect
    D. Mandibular anterior on the lingual aspect