Endodontics & Conservative Dentistry #5

1. The absence of which layer of dentin predisposes it to internal resorption by cells present in the pulp?

Mantle dentin

Circumpulpal dentin

Secondary dentin

Predentin

Question 1 of 20

2. Which portion of a gas flame should be used to melt gold casting alloys?

Blue - reducing zone

Green - combustion zone

Yellow - oxidizing zone

Red - heat zone

Question 2 of 20

3. A dentin bonding agent has two ends: hydrophilic and hydrophobic. The hydrophobic end binds to:

Composite resin

Smear layer

Enamel

Collagen in dentin

Question 3 of 20

4. Which cavities can involve only posterior teeth

class VI

class V

class II

class I

Question 4 of 20

5. The most important aspect of irrigation is:

olume of irrigant used

Chelating action of solution

Aspiration of solution

Lumen of needle

Question 5 of 20

6. The main purpose of finishing the enamel wall of a prepared cavity is to

Prevent microleakage

Remove loose enamel rods

Ensure parallelism of the walls

Smoothen the walls of the cavity to permit accurate adaptation of the restorative material

Question 6 of 20

7. In a class I cavity for amalgam, the mesial and distal walls show slight divergence towards the occlusal surface. This is done to:

Prevent placing amalgam margin at area of cuspal contact of opposite tooth

Prevent undermining of marginal ridges

Increase bulk of amalgam

Allow easier condensation of amalgam

Question 7 of 20

8. Root canal therapy was completed on a nonvital tooth that suffered trauma 5 years prior. At the time of obturation, the tooth exhibited a periapical radiolucency on radiographic examination. Radiographically, healing should be visualized in:

1 week

1 month

6 months

6 weeks

Question 8 of 20

9. After completion of root canal therapy, you recall your patient to evaluate the treatment outcome. What are the criteria for successful root canal therapy?1. Absence of pain 2. Absence of swelling 3. Sinus tract healing 4. No residual probing defects 5. Resolution or healing of periapical lesions

1, 3, 5

1, 2, 4, 5

2, 3, 4

1, 2, 3, 4, 5

Question 9 of 20

10. Retentive locks in the proximal box for a Class II amalgam preparation should be:

Round, elongated, placed in the dentin

Square shaped, elongated, placed at DEJ

Square shaped, placed in dentin

Sharp, elongated, placed within the dentin

Question 10 of 20

11. Pregnant patients in the first trimester

Should delay use of x-ray until the second trimester.

Should receive the normal x-ray dose for endodontic therapy.

Are not at risk from pharmacologic intervention.

Are not candidates for electronic apex locators.

Question 11 of 20

12. According to Kim et al Classification Class III isthmus indicates:

A complete or incomplete isthmus between three or more canals.

Complete isthmus with two canals with a definite connection between them.

A very short, complete isthmus between two canals.

Incomplete isthmus with a faint communication between two canals.

Question 12 of 20

13. A pin channel perforates the external surface of the tooth, all other factors are favorable, the next logical course of action should be to

Line the channel with cavity varnish and cement the pin with inc phosphate cement

Seal the channel with gold foil and observe the tooth for six weeks before restoring

Clean the channel and seal it with calcium hydroxide cement

Place a pin in the channel provided there is no extension beyond the tooth surface

Question 13 of 20

14. Painful pulpitis associated with an inflamed or degenerating pulp

is caused by a decrease in intrapulpal pressure.

results from a reduction of nerve cell permeability.

is most likely due to nociceptive C-fibcr activity.

is associated with stimulation of A fibers.

Question 14 of 20

15. To avoid external transportation of the root canal

precurve instruments.

use large instruments.

avoid the use of sodium hypochlorite.

use vigorous instrumentation.

Question 15 of 20

16. What distinguishes a base from a cement from a cavity liner?

Degree of pulpal protection

Final application thickness

Degree of hardness

Biocompatibility of material

Question 16 of 20

17. Cells in asymptomatic apical periodontitis lesions:

Derivatives of disintegrated cell membrane

Macrophages & lymphocytes

Foamy macrophages & neutrophils

Osteoclasts

Question 17 of 20

18. Electric pulp testing can give a false positive reaction in which of the following?

Calcified root canals

Patient on NSAIDs

Traumatic injury to teeth

Anxious patient

Question 18 of 20

19. The greatest potential hazard of chronic mercury toxicity occurs due to

Skin contact with mercury

Inhalation of mercury vapors

During amalgam restoration in a patient ,

Ingestion of amalgam scrap during removal of old restoration

Question 19 of 20

20. When preparing a pin channel, you perforate into the vital pulp chamber. What best describes your next step.

Explain to the patient the need for root canal treatment

Allow bleeding to stop, dry with paper point, place pin elsewhere, and restore with amalgam

Allow bleeding to stop, dry with paper point, place calcium hydroxide

Allow bleeding to stop, dry with paper point, place pin to depth of 1 mm as to not enter the pulp chamber

Question 20 of 20