is the hard dental tissue covering the anatomic roots of teeth and is formed by cells known as

cementoblasts, which develop from undifferentiated mesenchymal cells in the

connective tissue of the dental follicle.

Inorganic material Organic material +

Water

45% to 50% (hydroxyapatite)

* Fluride content is highest than other

calcified tissue of body .

50% to 55%mainly

90%is type 1 collagenAnd ground substance

consist of proteoglycans .

(matrix)

Cellular Acellular

Secondary CementumPrimary Cementum

Apical 3rd and inter-radicular region.Location: Cervical margin to 2/3rd of root.

Forms after tooth reaches occlusal plane.Formation: Forms before the tooth reaches occlusal plane.

Cellular, contains cementocytesCells: No

Thick and irregular.Structure: Thin and regular.

Less calcified.Calcification: More calcified

Fast .Rate of development : slow

Sharpey’s fibers occupy smaller portion Sharpey’s fiber are main compenent .

Irregular CC & regular AC

After formation of

dentin

Fragmentation of the epithelial

root sheath .

induce activity of mesenchymal cells of

dental follicle.

Continuous loss of epithelial root

sheath .

Allow adjacent cells of the investing layer of the

dental follicle to come to lie on surface of root

dentin

Cells are induced to differentiate

into cementoblasts.

Increased in size

Depositing the organic matrix of cementum

( intrinsic fibers + ground substance )

Cells trapped in lacunae within matrix formed

( secondary cementum )

Aceullar Afibrillar: Contains no cells, no fibers. Only mineralized ground substance present.

Produced by Cementoblasts and found in coronal cementum.

Aceullar Extrinsic Fiber: Contains Sharpey’s fibers but no cells.

Produced by Fibroblasts and Cementoblasts.

Found commonly in cervical 3rd of roots but may extend apically.

Cellular Intrinsic Fiber: Cells but no extrinsic fibers. Produced by Cementoblastsand fills resorption lacunae.

Cellular Mixed Stratified: Extrinsic and intrinsic fibers (hence mixed) and has cells. Co-product of Cementoblasts & Fibroblasts.In apical 3rd of toot and in furcation.

*Cellular and aceullar cementum are separated by lines that are parallel to the long axis of the root.

*More mineralized than adjacent cementum.

*They represent rest periods in cementum formation.

SMOOTH In permanent teeth.

ESCALLOPD In deciduous teeth.