Exam Questions & Answers (Sample 6)

Exam Questions & Answers (Sample 6)

Exam questions & answers (Sample 6)

1. Regarding the restoration of endodontically treated teeth, which of the following statements is incorrect?

a. Adequately condensed gutta percha can be safely removed immediately after endodontic treatment.

b. Both rotary and hand instruments can safely be used to remove adequately condensed gutta percha.

c. 4 to 5 mm of gutta percha should be retained to ensure an adequate apical seal.

*d. The removal of a portion of a silver point during post preparation is of no concern.

e. A zinc oxide eugenol provisional restoration placed over an obturated canal which is exposed to saliva for more. then three months requires that the canal in question be retreated.

Answer: d.

2. Regarding the restoration of endodontically treated teeth, which of the following statements is incorrect?

a. With long rooted teeth, achieving a post length as close as possible to three fourth's of the root length is desirable.

b. Post diameters should not exceed ore third of the root diameter at any location.

*c. Safe post diameters have been shown to range from .6 to 2 mm.

d. Cervical tooth structure should be retained.

e. Posts should not extend more then 7 nom apical to the canal orifice of molars because of an increased risk of perforation.

Answer: c.

3. When luting a fixed prosthesis, which of the listed cements will produce the smallest post cementation marginal opening?

a. Polycarboxylate.

b. Zinc Phosphate.

c. Microfilled BISGMA composite resin with NPGGMA/PMDM dentinal bonding agent (GMAPE).

*d. Glass lonomer.

e. Microfilled BISGMA I phosphate ester composite resin (GMA/PE).

Answer: d.

4. Which of the following statements regarding the use of resin cements is incorrect?

a. Post cementation marginal openings are three to four times a resin cements film thickness.

b. The degree of post cementation marginal opening seen with a resin cement is due to their immediate exponential setting mechanism.

c. These materials increase in viscosity to rapidly to flow and extrude from the margins of castings.

d. If the choice is made to use a resin cement with a particular casting, that casting should receive additional die relief or be vented.

*e. Resin cements should be manipulated carefully and quickly and the operator should apply a light seating load.

Answer: e.

5. Which of the following listed cements could be expected to have the weakest diametral and compressive tensile strengths?

a. Conventional powder liquid glass ionomer.

*b. Zinc Phosphate.

c. An encapsulated glass ionomer.

d. A composite resinglass ionomer hybrid.

e. A composite resin.

Answer: b.

6. Which of the following listed characteristics of titanium is incorrect:

*a. High modulus of elasticity.

b. High strength to weight ratio.

c. Light weight.

d. Excellent corrosion resistance.

e. Good local spot weldability.

Answer: a.

7. Which of the following statements regarding the reason for the use of beryllium in nonprecious alloys is incorrect?

a. It is used to reduce their fusion temperature.

b. It is used to improve their casting characteristics.

c, It is used to refine their grain structure.

*d. It is used to bind toxic elements in the "as cast" alloy.

e. It is used to strengthen these alloys.

Answer: d.

8. The following are all contraindications for non working occlusal adjustment except:

a. Tendency to tip or drift after adjustment.

b. Forces in relation to occlusion.

c. Effect on working side function.

d. Maintenance of centric stops.

*e. Character of protrusive path.

Answer: e.

9. All of the following criteria are true when assessing anterior gingival form except:

a. Tooth contact forms half of the interproximal contact, papilla forms the other half.

b. Gingival margin over the maxillary lateral incisor should be approximately 0.5mm coronal to the central incisor.

*c. Gingival margin over the maxillary lateral incisor should be approximately 0.5mm apical to the central incisor

d. The gingival levels over the two central incisors should be at the same height

e. The gingival margin of the canine should be at the same height as the

central incisor

Answer: c.

10. The mandibular low lip position can be observed and evaluated during speech. In pronunciation of the “S” sound, some patients expose the entire anterior mandibular and gingival contours. The “S” sound is known as a:

a. Silibant.

*b. Sibilant.

c. Sibling.

d. Syllabus.

e. Synkaryon.

Answer: b.

11. The deflection or bending of a fixed prosthesis varies directly with the cube of the length. Therefore a fixed prosthesis with two pontics will deflect ______more than a prosthesis with one pontic.

a. 2 times.

b. 4 times.

c. 6 times.

*d. 8 times.

e. 9 times.

Answer: d.

12. Which of the following statement about degassing ceramometals is false?:

a. Cleanses the metal of organic debris.

b. Removes entrapped surface gases.

*c. Should be performed under vacuum so as to maximize the amount of oxidation.

d. Removes volatile contaminants.

e. Allows specific oxides to form on the metal surface.

Answer: c.

13. Which of the following is not a contraindication to implant treatment:

a. High dose irradiated patients.

*b. Geriatric patients over 85 years of age.

c. Drug and/or alcohol abuse.

d. Patients with significant psychiatric problems.

e. Pathology of hard and soft tissue.

Answer: b.

14. Which of the following elements are not found in commercially pure titanium?

a. Oxygen.

b. Iron.

c. Carbon.

d. Hydrogen.

*e. Aluminum.

Answer: e.

15. Mutually protected articulation is defined as:

a. An occlusal scheme in which the posterior teeth prevent excessive contact of the anterior teeth in centric relation.

b. An occlusal scheme in which the posterior teeth prevent excessive contact of the anterior teeth in maximum intercuspation.

c. An occlusal scheme in which the anterior teeth disengage the posterior teeth in all mandibular excursive movements.

*d. b and c.

e. a and c.

Answer: d.

16. Posselt, Glickman, Arstad and Yurkstas demonstrated that maximal intercuspal relation of the teeth is anterior to terminal hinge position (centric relation) in approximately _____ of individuals with a full complement of natural teeth.

a. 80%

b. 85%

*c. 90%

d. 95%

Answer: c.

17. Which of the following prostheses benefits most from an anterior guide table?

a. Posterior fixed partial denture with canine protected articulation.

b. Preparation of opposing first molars with desired group function from premolars and canines in lateral excursions.

c. Maxillary central incisors with desired protrusive guidance from central and lateral incisors.

*d. Maxillary canine with desired canine protected articulation.

Answer: d.

18. Which of the following is true as the mandible generates an anterior opening border movement by closing from the maximally opened position to the maximally protruded position?

a. Since the condyles are stabilized by contraction of the lateral pterygoids, a pure hinge movement occurs.

b. The condyles are stabilized in their most anterior position by the lateral pterygoid muscles when the mandible is in its maximally protruded position.

c. Maximum opening is in the range of 20-40 mm when measured between the incisal edges of the maxillary and mandibular teeth.

*d. A pure hinge movement of the mandible does not occur when the mandible is closed from its maximally opened to its maximally protruded position, because tightening of the stylomandibular ligament during mandibular closure produces a posterior movement of the condyles.

Answer: d.

19. The proposed mode of occlusal therapy is best determined by examining the bucco-lingual relationship of opposing maxillary and mandibular teeth of an accurate diagnostic mounting of casts in centric relation. According to the “rule of thirds”, if the centric cusp tip contacts the opposing inner incline on the third closest to the cusp tip or even on the cusp tip, the appropriate occlusal management of the case is:

a. Selective grinding.

b. Fixed prosthodontics.

c. Orthognathic surgery.

*d. Orthodontics.

e. Operative dentistry.

Answer: d.

20. The component(s) found in gold dental solders responsible for narrowing the melting range, increasing the adherence of the solder to the metal, and increasing the flow of the solder is:

a. gold.

b. copper.

c. zinc and tin.

*d. silver.

e. platinum.

Answer: d.

21. Which of the following is a true characteristic of the chamfer margin preparation?

a. The chamfer margin design has shown experimentally to exhibit the most stress along the finish line.

b. The chamfer has an acute edge at the finish line to allow for accurate seating of the restoration.

*c. The chamfer has sufficient depth at the margins to provide for an adequate thickness of gold.

d. The chamfer offers an effective “slip joint” margin.

Answer: c.

22. The metal alloy routinely used in the construction of resin bonded fixed partial dentures is:

*a. Palladium nickel beryllium.

b. Gold silver

c. Chrome nickel cobalt.

d. Nickel chromium beryllium.

e. Chrome cobalt.

Answer: a.

23. According to Weinberg’s 1963 article, the third point of reference, located arbitrarily on the face in transferring a facebow to an articulator, defines the occlusal plane in relation to the horizontal condylar inclination. If the third point of reference is changed from orbitale to the ala of the nose this will affect the occlusal plane in relation to the condylar inclination how?

*a. The occlusal plane will become more superior at the anterior end.

b. The occlusal plane will become more inferior at the anterior end.

c. There will be no change in the occlusal plane.

Answer: a.

24. When making a provisional restoration for a patient who presents with a severely worn dentition, creating an anterior guidance that is too steep is likely to cause which of the following complications?

a. Periodontal abscess.

*b. Loosening of the provisional restoration.

c. Temporalis symptoms.

d. Clicking of the anterior teeth

e. Phonetic problems.

Answer: b.