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 I 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 the 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 bone & dentin

Answer 6

Mineral

Question 7

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

Answer 7

Avascular
Innervated
Haversian or Volkmann’s canals

Question 8

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

Answer 8

thinnest

Question 9

Cementum progressively increases in thickness to the 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, canaliculi)
Sharpey’s fibers (PDL)

Question 15

Both indicated incremental growth & run longitudinally within the cementum

Answer 15

Depositional & reversal lines

Question 16

Cementocytes contain ______ which are the space occupied by the cell & _____ 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 & compressive forces during tooth flexure

Answer 18

Abraction

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 ____ ares 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

Premolar & cuspids

Question 24

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

Answer 24

Cementicle

Question 25

What are the three 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 & 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 as trauma from occlusion, periapical inflammation, or compensation for occlusal attrition

Answer 32

Hypercementosis