Cementum

Question 1

What is cementum?

Answer 1

It is CALCIFIED, AVASCULAR MESENCHYMAL tissue that covers the anatomical root of the tooth from the CEJ to the root apex

Question 2

What are the components of CEMENTUM?

Answer 2

Collagen fibers 
  Extrinsic fibers 
  Intrinsic fibers 
Calcified interfibrillar matrix 
  proteoglycans, glycoproteins, phosphoproteins 
  cementoblasts

Question 3

What composes of the extrinsic fibers in cementum?

Answer 3

These fibers insert into cementum from PDL
Composed of SHARPEY’S FIBERS (type I collagen coated with type III collagen)
Produced by FIBROBLASTS

Question 4

What composes of the intrinsic fibers of cementum?

Answer 4

These fibers are produced inside of the cementum matrix

Produced by CEMENTOBLASTS

Question 5

What composes of the interfibrillar matrix in cementum?

Answer 5

Proteoglycans, glycoproteins, phosphoproteins

Produced by CEMENTOBLASTS

Question 6

What do the cementoblasts produce?

Answer 6

Intrinsic fibers
Calcified Interfibrillar matrix
Proteoglycans, glycoproteins, phosphoproteins

Question 7

The interfibrillary matrix is composed of intrinsic and extrinsic fibers

Answer 7

True

Question 8

Acellular/Primary cementum

What is it?

Answer 8

First formed
No cells 
Covers the cervical 1/3 to 1/2 of root 
Composed mainly of SHARPEY'S FIBERS
In disease acellular cementum can become necrotic leading to root caries and root sensitivity.

Question 9

Cellular/Secondary cementum

What is it?

Answer 9

Formed after tooth reaches occlusal plane
Cementocytes begin to form
Found in bifurcation, trifurcation, and apical regions of root
Occulsal forces influence cellular cementum deposition

Question 10

What are incremental lines of Salter?

Answer 10

More prominent in acellular cemntum
Indication of periods of rest during cementum formation
These lines are more mineralized than adjacent cementum

Question 11

What is the term for abscence or decrease of cellular cementum?

Answer 11

Cemental aplasia or hypoplasia

Question 12

What is the term for excessive cementum deposition?

Answer 12

Cemental hyperplasia or hypercementosis

Question 13

Does hypercementosis need to be treated, and if so what problems my arise?

Answer 13

No it does not need to be treated, but it may make EXTS of teeth rather difficult.

Question 14

Cementum resorption can be because of several causes, state some examples and what type of resorption they are to

Answer 14

Physiologic resorption
Pathologic resorption (local, systemic, idiopathic)
occlusal trauma, ortho, cysts, maligned erupting teeth
Calcium deficiency, hypothyroidism, Paget disease.
Idiopathic

Question 15

Ankylosis

Answer 15

Fusion of cementum with alveolar bone with loss of the PDL
No mobility
Infraocclusion
No proprioception

Question 16

Intermediate cementum

Answer 16

Poorly defined zone near CDJ that contains remnants of HERsheeth

Question 17

In cellular cementum, what may contribute to root sensitivity after SRP?

Answer 17

In cellular cementum, canaliculi may be continuous with dentinal tubules, which may contribute to root sensitivity after SRP.

Question 18

What are some functions of cementum?

Answer 18

Anchors Sharpey’s fibers of PDL to the to tooth surface
Protect root dentin decreasing sensitivity
Compensates for occlusal wear by continued cementum deposition
Repair of PDL space by permitting rearrangement of PDL fibers (post orthodontics)

Question 19

Positions of the CEJ occur where at on the tooth?

Answer 19

5-10% cementum and enamel do not meet
30% cementum and enamel butt up against each other
60-65% cementum overlaps enamel