Cementum- Exam II

Question 1

50-55% composition of cementum:

Answer 1

Organic

Question 2

45-50% composition of cementum:

Answer 2

mineral

Question 3

Organic components of cementum include: (4)

Answer 3

1. Type 1 collagen (intrinsic & sharpey’s fibers)
2. Proteoglycans
3. Glycosaminoglycans
4. Phosphoproteins

Question 4

What are the functions of cementum? (3)

Answer 4

1. provides attachment for PDL
2. May provide limited compensation for occlusal wear through continuous apical apposition
3. May participate in repair of root fracture

Question 5

Cementum is ____ in origin

Answer 5

ectomesenchymal

Question 6

Cementum contains less ____ than both bone and dentin

Answer 6

mineral

Question 7

Unlike bone, cementum is _____, not _____, and contains no ____ or _____ canals

Answer 7

avascular; not innervated; no Haversian or Volkmann’s canals

Question 8

Cementum is the _____ at the CEJ (30-50 micrometers)

Answer 8

thinnest

Question 9

Cementum progressively increased in thickness to 90-150 micrometers at the ____ to 150-300 micrometers at the ____.

Answer 9

mid-root; apex

Question 10

The cells responsible for the secretion of the organic matrix of cementum are derived from ______ cells that originate in the ______ zone of the _____.

Answer 10

Undifferentiated mesenchymal cells; proximal (inner) zone; dental follicle

Question 11

All cells in the dental follicle are derived from:

Answer 11

ectomesenchyme (neural crest cells)

Question 12

Differentiation is initiated with disruption of _____, allowing the undifferentiated mesenchymal cells to make contact with the adjacent dentin.

Answer 12

Hertwig’s epithelial root sheath

Question 13

What is responsible for inducing the differentiation process in embryogenesis of cementum?

Answer 13

dentin matrix growth factors (BMP, FGF, DMP)

Question 14

What are the histologic features of cementum?

Answer 14

Depositional lines
Reversal lines
Cementoblasts
Cementocytes- (lacunae and canaliculi)
Sharpey’s fibers (PDL)

Question 15

Both indicate incremental growth and run longitudinally within the cementum:

Answer 15

depositional and reversal lines

Question 16

Cementocytes contain _____ which are the space occupied by the cell. And _____ which is the space occupied by the cytoplasmic projections .

Answer 16

Lacunae; canaliculi

Question 17

PDL fibers passing into acellular cementum:

Answer 17

Sharpey’s fibers

Question 18

Loss of tooth surface at the cervical areas of teeth caused by tensile and compressive forces during tooth flexure:

Answer 18

Abfraction

Question 19

Abfraction affects ____ areas of the teeth

Answer 19

buccal/labial cervical areas

Question 20

Deep narrow V-shaped notch commonly affecting single teeth with excursive interferences or eccentric occlusal loads:

Answer 20

Abfraction

Question 21

Loss of wear of dental tissue caused by the rubbing of foreign substances (like a toothbrush):

Answer 21

abrasion

Question 22

Abrasion is usually located at _____ areas of the teeth and lesions are typically more _____ than _____.

Answer 22

cervical areas; wide than deep

Question 23

What teeth are most commonly affected by abrasion?

Answer 23

Premolars and cuspids

Question 24

Calcified bodies appearing on or in the cementum and in the PDL:

Answer 24

cementicle

Question 25

What are the 3 classifications of cementicles?

Answer 25

free, attached, or embedded

Question 26

A response to local trauma or hyperactive occlusion and appear in increasing numbers with increasing age:

Answer 26

cementicle

Question 27

Exposed cementum is ____ which prevents the reattachment of ___

Answer 27

hypermineralized; collagen

Question 28

Exposed cementum facilitates attachment of ___ & ___.

Answer 28

plaque and calculus

Question 29

Exposed cementum facilitates:

Answer 29

endotoxin absorption

Question 30

Cementum can play a role in:

Answer 30

periodontal disease

Question 31

The excessive production of cellular cementum that generally involves the apical 1/3 of the root

Answer 31

hypercementosis

Question 32

Etiology of ____ is variable involving such factors such as trauma from occlusion, periapical inflammaton, or compensation for occlusal attrition

Answer 32

hypercementosis