Cementum is the calcified tissue that forms the outer layer of the tooth root. There are two main types of cementum: acellular and cellular. Acellular cementum is the first type formed and does not contain cells, while cellular cementum forms later and does contain cells. Cementum is composed primarily of collagen fibers and undergoes continuous deposition throughout life to compensate for tooth eruption and attrition. It plays an important role in attaching the periodontal ligament fibers to the root and maintaining the health of the periodontium.

1. GOOD MORNING

2. CEMENTUM

3. DEFINITION
 Cementum is the calcified a vascular
mesenchmal tissue that forms the outer layer
cover of the anatomic root
 Types of cementum
 There are two main types of cementum they
are:- 1.A celluar cementum and
 2.cellular cementum
 The two main source’s of collagen fibers in
cementum are sharpey’s fibers which are the
embedded portion of principal fibers of the

4.  Periodontal ligament and are formed by the
fibroblasts
 Fibers that belong to cementum matrix and are
produced by cementoblasts
 Cementoblasts also form the non collagenous
components of the inter fibrillar ground
substance such as proteoglycans,
glycoproteins and phosphoproteins
 Proteoglycans are the most likely to play a role
in regulating cell-cell and cell-matrix
interactions

5.  COMPOSTION
 The major proportion of the organic matrix of a
cementum is composed of type one (90%) and
type three about (5%) collagens
 ACELLULAR CEMENTUM
 It is the first cementum formed, covers
approximately the cervical third or half of the
root and does not contain cell’s

6.  This cementum is formed before the tooth
reaches
the occlusal plane and it’s thickness ranges
froms
30 to 230 um
 Sharpey’s fibers are completely calcified, with
the mineral crystals. Oriented parallel to the
fibrils as dentin and bone except in a 10 -50
um wide zone near the cementodentinal
junction where they are only partially calcified

7.  Acellular cementum also contains intrinsic
collagen fibrils that are calcified and irregularly
arranged or parallel to the surface
 CELLULAR CEMENTUM
 Celluar cementum formed after the tooth
reaches the occlusal plane is more irregular
and contain cell’s (cementocytes) in individual
spaces (lacunae)

8. that communicate with each other through a
system of anastomising canaliculi
 Cellular cementum is less calcified than the
acellular type
 Sharpey’s fibers occupy a smaller portion of
cellular cementum and are separated by other
fibers that are arranged either parallel to the
root surface
 Both acellular and cellular cementum are
aranged in lamellae separated by incremental
lines parallel to long axis root this lines are
called rest periods

9.  PERMEABILITY OF CEMENTUM
 In very young animal’s acellular cementum
and cellular cementum are very permeable
and permit the diffusion of dyes from the pulp
and external root suface
 THICKNESS OF CEMENTUM
 Cementum deposition is a continuous process
that proceeds at varying rates

10.  Cementum formation is most rapid in the
apical regions where it compensates for tooth
eruption, which it self compensate for attrition
 The thickness of cementum on the coronal half
of the root varies from 16-60um
 It attains greatest thickness (upto 150-200 um)
in the apical third and in the fraction areas
 Abnormalities in the thickness of cementum
may range from an absence of cellular
cementum to an excessive deposition of
cementum

11.  The term hyper cementosis refers to a
prominent thickening of cementum
 Hyper cementosis occurs a generalisied
thickening of the cementum
 CEMENTUM RESORPTION AND REPAIR
 Cementum resorption may be caused by local
and systemic factors

12.  Local condition causing cementum resorption
include trauma from occlusion orthodontic
movement pressure from malaligned erupting
teeth cysts and tumors teeth with out junctional
antagoinsts
 Systemic condition citied as predisposing to or
including cemental resorption include calcium
deficiency hypothyroidism, hereditary fibrous
osteodystrophy

13.  EXPOSURE OF CEMENTUM TO ORAL
ENVIRONMENT
 Cementum becomes exposed to the oral
environment in cases of gingival recession and
as result of loss of attachment in pocket
formation
 CEMENTO ENAMEL JUNCTION
 The cementum at and immediately subjacent to
cemento enamel junction is of particular clinical
importance in root scaling procedures

14.  Three types of relationships involving the
cementum may exists at cementoenamel
junction
 in about 60 -65% of cases, cementum over
laps the enamel in about 30% an edge-edge
but joint exists and 5-10% the cementum and
enamel fail to meet
 CEMENTO DENTINAL JUNCTION
 The terminal apical area of cementum where it
joins the internal root canal dentin is known as
cemento dental junction

15. THANK YOU
GUIDED BY
DR. KRISHNA MOORTHY. MDS
DR. ROOPA DEVI. MDS
DR. RAVEENDHAR REDDY. MDS
DR. SHARATH. MDS
DR.VENKAT SUBBA REDDY. MDS SUBMITTED BY
DR. PRADEEP. MDS N.V.GAYATRI
SAROJINI
IV BDS