Cementum Flashcards
Where is cementum located?
it covers the root portion of the dentin
What produces cementum?
cementoblasts
What are cementocytes?
trapped cementoblasts in the lacunae
What are the 4 functions/purposes of cementum
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)
How is cementum related to sensitivity
it is important to preserve cementum as it covers the dentin and dentinal tubules to prevent sensitivity
Characteristics of Cementum
- light yellow (more yellow than enamel but less than dentin)
-no luster/shine
-feels frosted to the touch
What is the composition of cementum?
-50% Organic Matrix & Water (fiber and collagen, no blood vessels ,nerves or lymphatics; not hard)
-50% inorganic material (minerals- calcium, phosphorus; 50% mineralized)
Where does the cementum receive its nourishment
the PDL
What is cementogenisis
process of cementum formation (incremental lines are in cementum)
What are the two types of Cementum?
Acellular and Cellular
Describe Acellular Cementum
-cementum w/o cells
-present in cervical half of root
-about 10-50 microns thick
-AKA cementoid or intermediate cementum
Describe Cellular Cementum
-contains cells (cementoblasts and cementocytes)
-apical half of root
-50-200 microns thick
What is the name for a mature cementum cell
cementocytes
Where will additional cementum be laid down over the years? Apical or Cervical third?
apical
Describe cementum related to resorption
cementum doesn’t resorb or break down as easily as bone or dentin does (this is what allows us to move teeth orthodontically)
Where is the cementum thin and where is it thick?
Thinner- CEJ, Cervical portion, cervical 3rd
Thicker-apical 3rd
60-65% of the time…
cementum will overlap enamel
30% of the time …
cementum and enamel will meet
5-10% of the time…
there is a gap
Lacuna
small hole in cementum where cementocytes live
canliculi
extensions or small canals that connect lacunas to eachother
cementicles
-small pieces of cementum that form along root surface causing it to feel bumpy
-typically seen in people over 40
hypercementum
overgrowth of cementum (cementum tumor); causes no harm and dentist may have difficulty removing
cementoma
-benign tumor of cementum
-appears gray in color
cementoclasia
a short root resulting from root resorption (possibly from moving teeth too fast)
Aberrant Cementum
features along root surface related to age; cementum where it shouldn’t be
Pressure Atrophy
tissues will degenerate and go away from old age; bones resorbing over time
Diffuse Atrophy
withering away of muscles - paralyzation
When are you most susceptible to caries on cementum
when recession is present, the clinical root is exposed and there is a decrease in salivary flow
