Cementum

Question 1

Where is cementum located?

Answer 1

it covers the root portion of the dentin

Question 2

What produces cementum?

Answer 2

cementoblasts

Question 3

What are cementocytes?

Answer 3

trapped cementoblasts in the lacunae

Question 4

What are the 4 functions/purposes of cementum

Answer 4

Protection: protect dentins/tubules

Prevention: prevent breakdown of dentin (resorption)

Retain: helps to keep tooth in socket by PDL fibers that connect from bone to cementum

Repair: can heal itself (tooth falls out you can stick it back in to heal)

Question 5

How is cementum related to sensitivity

Answer 5

it is important to preserve cementum as it covers the dentin and dentinal tubules to prevent sensitivity

Question 6

Characteristics of Cementum

Answer 6

• light yellow (more yellow than enamel but less than dentin)

-no luster/shine

-feels frosted to the touch

Question 7

What is the composition of cementum?

Answer 7

-50% Organic Matrix & Water (fiber and collagen, no blood vessels ,nerves or lymphatics; not hard)

-50% inorganic material (minerals- calcium, phosphorus; 50% mineralized)

Question 8

Where does the cementum receive its nourishment

Answer 8

the PDL

Question 9

What is cementogenisis

Answer 9

process of cementum formation (incremental lines are in cementum)

Question 10

What are the two types of Cementum?

Answer 10

Acellular and Cellular

Question 11

Describe Acellular Cementum

Answer 11

-cementum w/o cells
-present in cervical half of root
-about 10-50 microns thick
-AKA cementoid or intermediate cementum

Question 12

Describe Cellular Cementum

Answer 12

-contains cells (cementoblasts and cementocytes)
-apical half of root
-50-200 microns thick

Question 13

What is the name for a mature cementum cell

Answer 13

cementocytes

Question 14

Where will additional cementum be laid down over the years? Apical or Cervical third?

Answer 14

apical

Question 15

Describe cementum related to resorption

Answer 15

cementum doesn’t resorb or break down as easily as bone or dentin does (this is what allows us to move teeth orthodontically)

Question 16

Where is the cementum thin and where is it thick?

Answer 16

Thinner- CEJ, Cervical portion, cervical 3rd

Thicker-apical 3rd

Question 17

60-65% of the time…

Answer 17

cementum will overlap enamel

Question 18

30% of the time …

Answer 18

cementum and enamel will meet

Question 19

5-10% of the time…

Answer 19

there is a gap

Question 20

Lacuna

Answer 20

small hole in cementum where cementocytes live

Question 21

canliculi

Answer 21

extensions or small canals that connect lacunas to eachother

Question 22

cementicles

Answer 22

-small pieces of cementum that form along root surface causing it to feel bumpy

-typically seen in people over 40

Question 23

hypercementum

Answer 23

overgrowth of cementum (cementum tumor); causes no harm and dentist may have difficulty removing

Question 24

cementoma

Answer 24

-benign tumor of cementum

-appears gray in color

Question 25

cementoclasia

Answer 25

a short root resulting from root resorption (possibly from moving teeth too fast)

Question 26

Aberrant Cementum

Answer 26

features along root surface related to age; cementum where it shouldn’t be

Question 27

Pressure Atrophy

Answer 27

tissues will degenerate and go away from old age; bones resorbing over time

Question 28

Diffuse Atrophy

Answer 28

withering away of muscles - paralyzation

Question 29

When are you most susceptible to caries on cementum

Answer 29

when recession is present, the clinical root is exposed and there is a decrease in salivary flow