MCQs in Oral Histology

Chapter 6: Dentin

 

1-Interglobular spaces:

  1. Do not contain dentinal tubules.
  2. Do not contain type I collagen.
  3. Are formed during the course of globular mineralization.
  4.  Are seen only in secondary dentin.

 

 

 

 

 

 

 

The answer is: C

 

2- Which would not be present in a ground section?

  1. Inorganic crystals.
  2. Odontoblast.
  3. Interglobular space.
  4. Dentinal tubules.

 

 

 

 

 

 

 

The answer is: B

 

3- A major difference between secondary and primary dentine is that:

  1. There is no predentine.
  2. There is no hydroxyapatite.
  3. There is no collagen fibers.
  4. The dentinal tubules pass in wavier course through secondary dentine.

 

 

 

 

 

 

 

The answer is: D

 

4- The interglobular dentin is found:.

  1. Near the amelo-cemental junction.
  2. In the root dentin.
  3. Near the amelo-dentinal junction.
  4. Near the dentino-cemental junction.

 

 

 

 

 

 

 

 

The answer is: C

 

5- Which of the following is MOST likely to be found in the dentinal tubules:             

  1. Tomes' fibers.
  2. Oxytalan fibers.
  3. Tomes' process.
  4. Thick collagen fibers.

 

 

 

 

 

 

 

 

The answer is: A

 

6- Primary dentin differs from both secondary and reparative dentin in that:

  1. Its matrix is calcified.
  2. Its inorganic component is hydroxyapatite.
  3. It usually has a greater number of tubules per unit area.
  4. It is produced by mesenchymal cells.

 

 

 

 

 

 

 

The answer is: C

 

7- Which of the following is not present within dentin?

  1. Cell bodies.
  2. Hydroxyapatite.
  3. Collagen type I.
  4. Incremental lines.

 

 

 

 

 

 

 

The answer is: A

 

8- Which of the following is true of  peritubular dentin ?It :

  1. Is less mineralized than intertubular dentin.
  2. May be considered as intratubular dentin.
  3. Is best visualized in decalcified sections.
  4. Is found in the interglobular dentin.

 

 

 

 

 

 

 

 

The answer is: B

 

9- Which of the following is not present in odontoblasts?

  1. Golgi saccules and vesicles.
  2. Rough endoplasmic reticulum.
  3. Desmosome-like junctions.
  4. Numerous processes forming a striated border.

 

 

 

 

 

 

 

 

The answer is: D

 

 

10- Human primary dentin contains:

  1. Mantle & circumpulpal dentin.
  2. Tomes' process.
  3. Cell bodies.
  4. Atubular dentin.

 

 

 

 

 

 

 

 

The answer is: A

 

11- Which of the following is considered as age changes?

  1. Transparent dentin.                
  2. Cellular cementum.                 
  3. Primary dentin.
  4. Enamel spindle.

 

 

 

 

 

 

 

The answer is: A

 

12- Which of the following is true:

  1. A layer of predentin is found between primary and secondary dentin.
  2. Dentinal tubules do not pass through interglobular dentin.
  3. The physiological  secondary  dentin contain dentinal tubules.
  4. Many large collagenous fiber bundles are found in the dentinal tubules.

 

 

 

 

 

 

 

The answer is: C

 

 

13- Reparative dentin:

  1. Contain regular and numerous dentinal tubules.
  2. Obliterates the apical foramen.
  3. Forms on localized regions of the pulpal surface of the dentin.
  4. Formation is induced by the cells of the inner dental epithelium.

 

 

 

 

 

 

 

The answer is: C

 

14- Matrix vesicles are present during:

  1. The initial mineralization of dentin. 
  2. The initial mineralization of enamel.
  3. The initial mineralization of cementicles. 
  4. The initial mineralization of denticles.

 

 

 

 

 

 

 

 

The answer is: A

 

15- Which of the following is least prominent in odontoblasts and secretory ameloblasts?

  1. Rough endoplasmic reticulum
  2. Mitochondria
  3. Golgi apparatus
  4. Lysosomes

 

 

 

 

 

 

 

The answer is: D

 

16- Collagenous fibers are not found in:

  1. Mantle dentin.
  2. Reparative dentin.
  3. The outer prismless layer.
  4. The dental sac.

 

 

 

 

 

 

 

The answer is: C

 

17- Obliteration of the dentinal tubules by mineral deposits:

  1. Occurs only when the dentin becomes exposed to the oral fluids.
  2. Produces dead tracts.
  3. First occurs in predentin.
  4. Is seen in sclerotic and transparent dentine.

 

 

 

 

 

 

 

The answer is: D

 

18- Tome's granular layer is:

  1. An extension of odontoblast processes into enamel.
  2. A  region lacking dentinal tubules.
  3. Following the incremental lines.
  4. Derived from the epithelial rests of Malassez.

 

 

 

 

 

 

 

The answer is: B

 

19- Amelogenesis and dentinogenesis are similar in which respect?

  1. Both processes involve the secretion of collagenous fibers 
  2. impregnation with hydroxy-apatite crystals.
  3. Both processes involve maturation with hydroxyappatite crystals.
  4. Both processes start simultaneously at the early crown stage.
  5. Both processes continue throughout the life of the tooth.

 

 

 

 

 

 

 

The answer is: B

 

20- Which of the following is wrong?

  1. The formation of primary dentin continues throughout life.
  2. Primary dentin contains a significantly higher number of tubules per unit volume.
  3. Reparative dentin forms as a response to injury.
  4. Dead tracts are more common in secondary than in primary dentin.

 

 

 

 

 

 

 

 

The answer is: A

 

21- Which of the following has the highest mineral content?

  1. Predentin.
  2. Peritubular dentin.
  3. Intertubular dentin.
  4. Cementum.

 

 

 

 

 

 

 

The answer is: B

 

22-Dentin is a variety of Connective tissue because it:

  1. is elastic and contains mucopolysaccharides.
  2. contains collagen fibers and cell processes derived from mesenchyme.
  3. contains inorganic cells.
  4. has few cells and much intercellular material.

 

 

 

 

 

 

 

 

The answer is: B

 

23-Cementum is a tissue that:

  1. provides attachment of periodontal ligament fibers.
  2. is easily resorbed than bone.
  3. it contains blood vessels.
  4. it contains neural receptors.

 

 

 

 

 

 

 

The answer is: A

 

24-Cementum deposition cervically on enamel surface is due to:

  1. premature degeneration of epithelial root sheath of Hertwig.
  2. loss of reduced enamel epithelium.
  3. persistence of epithelial root sheath of Hertwig.
  4. cementoblasts coming from dental sac.

 

 

 

 

 

 

 

The answer is: B

 

25-Neonal line is present in:

  1. enamel and cementum.                   
  2. dentin and cementum.
  3. enamel and dentin.                           
  4. none of the above. 

 

 

 

 

 

 

 

The answer is: C

 

26-Obliteration of dentinal tubules by minerals will result in:

  1. formation of dead tracts.                 
  2. formation of secondary dentin.
  3. formation of sclerosed dentin.
  4. formation of irregular or reparative dentin.

 

 

 

 

 

 

 

 

The answer is: C

 

27-Age changes will increase:

  1. dentin sclerosis.                                  
  2. interglobular dentin.
  3. in cementum thickness.                      
  4. Tome's granular layer.

 

 

 

 

 

 

 

 

The answer is: A

 

28-formation of matrix vesicles in calcification of dentin is limited to:

  1. circumpulpal dentin.                
  2. Mantle dentin.
  3. all types of dentin.                   
  4. non of the above.

 

 

 

 

 

 

 

The answer is: B