MCQs in Endodontics

Chapter 12: Dentin Pulp complex

 

1- Blood vessels become established in the dental papilla:

  1. before the formation of the cervical loop.
  2. during the bud stage of t o o t h formation.
  3. during the bell stage of tooth formation.
  4. during the cap stage of tooth formation.

 

 

 

 

 

 

The answer is: C

 

2- Root development begins:

  1. before enamel formation.
  2. concurrently with enamel formation.
  3. after completion of enamel formation.
  4. before Hertwig's epithelial root sheath formation.

 

 

 

 

 

 

The answer is: C

 

3- The cell-rich zone:

  1. is more prominent in the radicular pulp than in the coronal pulp.
  2. exhibits increased mitotic activity following death if odontoblasts.
  3. is the result of the central migration of cells from the periphery following completion of dentin formation.
  4. contains mainly macrophages and endothelial cells and few fibroblasts.

 

 

 

 

 

 The answer is: B

 

4- Although similar in function, the odontoblast differs from the osteoblast and cemcntoblast in:

  1. morphologic characteristics.
  2. ultrastructure.
  3. matrix production.
  4. being a protein-secreting cell.

 

 

 

 

 

 

The answer is: A

 

5- The extent to which the odontoblast process extends outward in dentin:

  1. has been shown conclusively in recent years.
  2. varies with the age of the tooth.
  3. depends on continued mitotic activity of the odontoblast.
  4. is unrelated to the effects on the pulp of restorative procedures.

 

 

 

 

 

The answer is: B

 

6- Fibroblasts:

  1. are the least numerous cells of the pulp.
  2. are capable of giving rise to cells that may differentiate into macrophages.
  3. increase in numbers as blood vessels and nerves decrease with age.
  4. undergo active differentiation in the pulp, as do fibroblasts of other connective tissues.

 

 

 

 

 

 

The answer is: D

  

7- Water content of the pulp is approximately:

  1. 30%.
  2. 50%.
  3. 70%.
  4. 90%.

 

 

 

 

 

The answer is: D

 

8- Regardless of the nature of the sensory stimulus, all afferent impulses from the pulp result in the sensation of:

  1.  proprioception.
  2. pain.
  3. heat.
  4. touch.

 

 

 

 

 

 

The answer is: B

 

9- The nerve fibers of the pulp are:

  1. mainly myelinated fibers at the time of tooth eruption.
  2. easily damaged by inflammation.
  3. only sensory.
  4. unevenly distributed throughout the pulp.

 

 

 

 

 

 

The answer is: D

 

10- Fluid movement in dentinal tubules is known as the:

  1. hydrodynamic theory.
  2. osmotic pressure.
  3. mechanical deformation theory.
  4. hydraulic theory.

 

 

 

 

 

 

The answer is: A

 

11- Painful pulpitis associated with an inflamed or degenerating pulp:

  1. is caused by a decrease in intrapulpal pressure.
  2. results from a reduction of nerve cell permeability.
  3. is associated with stimulation of A fibers.
  4. is most likely due to nociceptive C-fibcr activity.

 

 

 

 

 

 

The answer is: D

 

12- Volume of blood flow in the pulp:

  1. is least in the regions of the pulp horns.
  2. is greater in the root portion than in the crown portion.
  3. is greater than the blood flow in most visceral organs.
  4. is largely under the control of the adrenergic sympathetic system.

 

 

 

 

 

 

The answer is: D

 

13- A healthy dental pulp responds to an injury by:

  1. developing an effective collateral circulation to transport inflammatory elements to the area.
  2. decreasing in blood flow throughout the pulp.
  3. initiating an inflammatory response, usually followed by partial or complete necrosis.
  4. forming reparative dentin at the pulpal surface corresponding to areas of irritation.

 

 

 

 

 

 

The answer is: D

 

14- Pulpal calcifications:

  1. may compromise the pulpal blood supply.
  2. arc of no significance in root canal therapy.
  3. have an organic matrix of collagen in all sizes.
  4. occur only after eruption.

 

 

 

 

 

 

The answer is: C

 

15- Calcific metamorphosis:

  1. is caused by increased activity of odontoblasts.
  2. may lead to complete obliteration of the pulp space.
  3. usually occurs in association with a constricted apical foramen.
  4. histologically resembles aceliular cementum.

 

 

 

 

 

 

The answer is: A

 

16- Growth factors arc likely to be involved in tooth formation. What is at least one probable function of these factors:

  1. Signaling epithclial-mescnchymal interactions.
  2. One of the eruptive forces located in the apical region.
  3. Disruption of Hcrtwig's epithelial root sheath.
  4. Collagen maturation in the dental papilla.

 

 

 

 

 

 

The answer is: A

 

17- The cell type to which the dendritic cell is most similar is:

  1. fibroblast.
  2. t-lymphocyte.
  3. mesenchymal cell.
  4. macrophage.

 

 

 

 

 

 

The answer is: D

 

18- Lymphatics in the dental pulp:

  1. have not been demonstrated.
  2. would not be necessary because of the extensive vascular network.
  3. cannot be demonstrated morphologically because they are identical to venules.
  4. participate in the removal of tissue fluids.

 

 

 

 

 

 

The answer is: D

 

19- What would be the closest estimate of the number of tubules exposed with a full crown preparation of average depth that would have a surface area of 100 mm2:

  1. 5000
  2. 50,000
  3. 500.000
  4. 5,000,000

 

 

 

 

 

 

The answer is: D

  

20- When the pulp is injured it responds with inflammation. Why does it not have good capability for recovery if badly damaged?

  1. It has no collateral blood supply.
  2. It lacks lymph drainage.
  3. Pulp C.T. cells are incapable of mitosis.
  4. It is encased in a noncompliant environment.

 

  1. 1 & 2.
  2. 1 &3.
  3. 1 &4.
  4. 2 & 3.

 

 

 

 

 

 

The answer is: C