3. Physical Characteristics
1-Color
Light yellow
Lighter in color than dentin
2- Thickness
Acellular cementum (20-50 m)
Cellular cementum (150-200 m)
3- Permeability
Permeable from dentin and PDL sides.
Cellular C is more permeable than acellular C.
4. Chemical Composition
45-50 % Inorganic 50-55% Organic
substances substances
Collagen
Hydroxyapatite
crystals protein
Polysaccharides
Trace elements
Cementum contains the greatest amount of
fluoride in all mineralized tissues
7. Acellular Cementum
Thickness is 20-50 µ.
It is clear and structureless
Covers the coronal half of
the root.
Incremental lines of Salter
are parallel to the surface.
Sharpey’s fibers space can
be seen in it .
16. Cemento Enamel Junction
10% cementum and enamel
don’t meet because of 60%
30% cementum
cementum
meets the enamel delayed separation of epith
overlaps E
in a sharp line root sheath of Hertwig (area
of dentin not covered by C). (afibrillar
cementum)
17. Afibrillar Cementum
Before tooth eruption, The connective tissue of
the enamel at the the dental sac lay down
cervical area lose its cementum on the
REE covering. exposed enamel
19. Functions Of Cementum
1- Acts as a medium for
attachment of collagen
fibers of PDL
(Sharpey’s fibers).
2- The continuous Cementoid T
formation of cementum
keeps the attachment
apparatus intact.
Cementoblast
20. 3- Cementum
deposition epically
compensate for the
attrition.
4- It is a major
reparative tissue
( as in case of fracture
or resorption of
root)
21. Cementogenesis
• 1- Matrix formation • 2- Mineralization
and Maturation
Collagen Ground Hydroxy apatite
fiber type I substance crystals
22. 1- Matrix formation
• Cementum is
formed during root Cementoblasts
formation
D
HER
Future C E J Epith. Diaph.
23. Cementoblast is a protein forming and secreting cell.
Collagen fibers +
ground substance.
D
Large nucleus with dispersed
chromatin threads.
Cementoblast
RER
Golgi apparatus
Mitochondria
Secretory granules
Alkaline phosphatase
