This document provides an overview of cementum, including: - Cementum is the calcified tissue covering tooth roots that provides attachment for periodontal ligament fibers. - It is classified based on the presence of cells, fiber composition, and location on tooth roots. Thickness varies along roots and increases with age. - Cementum undergoes continuous deposition but is resistant to resorption under forces. It plays a role in tooth attachment and repairing root surfaces. - Alterations can occur due to disease, trauma, systemic factors and periodontal pathology like calculus attachment and root resorption in pockets.

1. Dr. Shraddha Shah

2.  INTRODUCTION
 HISTORY
 DEFINITION
 CEMENTOGENESIS
 PROPERTIES
 CLASSIFICATION
 CEMENTOENAMEL JUNCTION
 CEMENTODENTINAL JUNCTION
 THICKNESS
 FUNCTION

3.  AGE CHANGES
 RESORPTION AND REPAIR
 CEMENTUM IN DISEASE
 DEVELOPMENTAL ANOMALIES
 REGRESSIVE ALTERATIONS OF TEETH
 ALTERATIONS RESULTING FROM PERIODONTAL
PATHOLOGY
 NEOPLASMS OF THE CEMENTUM
 SYSTEMIC DISEASES AND ITS INFLUENCE ON
CEMENTUM
 APPLICATION IN FORENSIC ODONTOLOGY
 CONCLUSION
 REFERENCES

4.  Periodontium consists of investing layer and supporting
tissues of the tooth: gingiva, periodontal ligament,
Cementum and alveolar bone.
 Divided into 2 parts:
 Gingiva : protects the underlying tissues
 Attachment apparatus : composed of PDL, cementum and
alveolar bone
 Cementum is considered a part of the periodontium because,
with the bone - supports fibres of PDL.

5.  It was first demonstrated microscopically in 1835
by 2 pupils of Purkinje
 Hard bone like tissue covering the anatomic roots
of the teeth(Newman et al, 2006)
 The word cementum is derived from a Latin word
Caementum, “quarried stone”

6.  Cementum is a calcified, avascular mesenchymal
tissue that forms the outer covering of anatomic root.
(Newman et al,2006)
 Cementum is the thin, calcified tissue of
ectomesencymal origin covering the roots of teeth.
(Glossary of Periodontology)

7.  Formation of cementum can be subdivided into:
1) prefunctional developmental stage: formed during the root
development- 3.5 and 7.5 years.
2)functional developmental stage: commences when the tooth is
about to reach the occlusal level.
- associated with attachment of root to bone
- continues throughout life- adaptive and reparative processes are
carried out by the biological responsiveness of cementum.
- influences the alterations in the distribution and appearance of
the cementum varies on the root surface with time.

10.  PHYSICAL PROPERTIES:(Berkowitz et al, 2002)
1) Pale yellow with dull surface
2) softer than dentin
3) permeability
-cellular variety more permeable as the canaliculi in some areas
are continuous with the dentinal tubules
- more permeable than dentine
- decreases with age
4) soft and thin cervically- readily removed by abrasion when
gingival recession exposes the root surface to the oral
environment.

11.  CHEMICAL PROPERTIES(Berkowitz et al, 2002)
1) on the basis of weight:
inorganic – 65%
organic – 23%
water – 12%
2) on the basis of volume:
inorganic – 45%
organic –33%
water – 22%

12.  BASED ON PRESENCE OR ABSENCE OF CELLS
 Cellular Cementum
- contains cells(cementocytes)
- found in the apical and interradicular areas and overlying
the acellular cementum
- formed after acellular- secondary cementum
- faster rate of matrix formation – incremental lines farther
- presence of precementum
- spaces that the cementocytes occupy are called lacunae
and the channels that their processes extend along are the
canaliculi

13. - adjacent canaliculi are often connected and the
processes within them exhibits gap junction
- cementocytes are more widely dispersed and more
randomly arranged
- canaliculi preferentially oriented towards PDL –
chief source of nutrition
- once embedded cementocytes become relatively
inactive
- border with dentin is clearly demarcated

14. Acellular Cementum
- appears relatively structureless- no cells
- first formed – primary cementum
- covers the root adjacent to the dentine more in the
cervical 2/3
- slower rate of matrix formation
- incremental lines are closer
- precementum is virtually absent
- border with dentin is not clearly demarcated

15. ACELLUAR CEMENTUM CELLULAR CEMENTUM
1. Primary cementum. Secondary Cementum
2. Present on cervical third or half of
the root.
Mainly on apical third of root
3. It does not contain cells. It contain cells called cementocytes in
individual spaces lacunae
4. It is formed before the tooth reaches
the occlusal plane.
Formed after the tooth reaches the
occlusal plane
5. More calcified. Less Calcified
6. Sharpey’s fibers are main component
which inserted at approximately right
angles onto the root surface.
Sharpey’s fibers occupy smaller portion
& occupy other fibers that are arranged
parallel to the root surface.

16.  BASED ON THE NATURE AND ORIGIN OF THE
ORGANIC MATRIX:
cementum derives its organic matrix from 2 sources
 Extrinsic Fibers: from inserting sharpey’s fibers of the
periodontal ligament- perpendicular or oblique to the root
surface
 Intrinsic Fibers: from cementoblasts- run parallel to the
root surface and approximately at right angles to extrinsic
fibers
 Mixed Fiber Cementum: both the above fibers are
present

17.  Based on presence or absence of cells and the nature
and origin of the organic matrix-
(Schroeder’s classification)
ACELLULAR AFIBRILLAR CEMENTUM(AAC):
- Contains neither cells nor extrinsic or intrinsic collagen
fibers
- only mineralized ground substance
- product of cementoblasts
- found as coronal cementum
- thickness – 1 to 15 µm

18.  ACELLULAR EXTRINSIC FIBER
CEMENTUM(AEFC):
- Composed almost entirely of densely packed bundles of
sharpey’s fibers
- Product of fibroblasts and cementoblasts
- Cervical third of roots but may extend farther apically
- Thickness – 30-230µm
 CELLULAR MIXED STRATIFIED
CEMENTUM(CMSC):
- Composed of extrinsic and intrinsic fibers
- May contain cells
- Co-product of fibroblasts and cementoblasts
- Primarily in the apical third, apices and in furcation areas
- thickness – 100-1000µm

19.  CELLULAR INTRINSIC FIBER
CEMENTUM(CIFC):
- Contains cells, but no extrinsic collagen fibers
- Formed by cementoblasts
- Fills resorption lacunae
 INTERMEDIATE CEMENTUM:
- poorly defined zone near cementodentinal
junction of certain teeth that appears to contain
cellular remnants of Hertwig’s sheath embedded in
calcified ground substance

22.  Varies at different levels of the root
 Thickest at the root apex and interradicular areas
of multirooted teeth – 50-200µm (may exceed to
600µm)
 Thinnest cervically – 10-15µm
 Thickest in distal side than mesial due to mesial
drift
 Between ages 11 and 70 – thickness increases 3 fold
– 95µm at 20yrs and 215µm at 60yrs (Zander and
Hurzler, 1958)
 Impacted teeth have thin cementum

23.  Cementum provide a medium for the attachment to the
collagen fibers of periodontal ligament.
 Cementum is hard & has no blood supply, It does not show
resorption under masticatory or orthodontic forces. Thus,
during heavy orthodontic forces, tooth integrity is
maintained & alveolar bone being elastic in nature changes
its shape, fulfilling the orthodontic requirement.
 Cementum has property of continuous deposition & does
the patch work or repair for the damage such as fracture or
resorption of tooth surface.
 Regular Cementum deposition at the root apex, helps to
replenish the lost tooth height due to occlusal wear or
helps in passive eruption of teeth.

24.  Continuous deposition:
 Cementum formation continues throughout life
unless disturbed by periapical or periodontal
pathology
 Deposited at a linear rate (Azaz et al, 1974)
 More cementum is formed apically than
cervically
 Cementum thickness shows variations among
tooth groups and surfaces
 Thick layers may form in root surface grooves
and furcations of multirooted teeth
 Great variations in incremental lines indicate
that rate of cementum formation may vary

25.  Types of resorption:
 Physiological root resorption : normal phenomenon of
deciduous teeth during tooth shedding
 Causes for resorption of permanent teeth
 pathological like infectious, systemic diseases like
calcium deficiency, hypothyroidism, hereditary
fibrous osteodystrophy and Paget’s disease or tumors
 nonpathological like trauma (mechanical, chemical
or thermal) or sustained overcompression of the
PDL
 idiopathic
 Root resorption classified according to location as
 Internal
 External

26.  According to degree of persistence
 Transient
 Progressive
 Root surface is more resistant to resorption than bone
 No. of teeth resorbed and severity of resorption are
markedly increased by orthodontic treatment
 Appears microscopically as bay like concavities in the
root surface
 Multinucleated giant cells and large mononuclear
macrophages are generally found adjacent to
cementum
 May extend into underlying dentin
 Not necessarily continuous, may alternate with
periods of repair and deposition of new cementum,
new cementum is demarcated from the root by a
deeply staining irregular line - reversal line

27.  Repair:
 Following detachment of odontoclasts from the
root surface, cementogenic cells repopulate in
the How ship's lacunae and attach the initial
repair matrix to a thin decalcified layer of
residual and exposed collagen fibrils
 Basophilic and electron dense reversal line
forms at the fibrillar junction
 Deposited repair matrix resembles cellular
intrinsic fiber cementum
 Cementum repair requires viable connective
tissue
 Can occur in devitalized and in vital teeth

28.  There various studies in the past years that have shown
that Enamel matrix protein(s) are involved in the
development of cementum and that these proteins
may be used as a means to regenerate acellular
extrinsic fibre cementum.

29.  Cementum reactions to physiological tooth
movement and occlusal forces:
 Presence of cementum on impacted teeth
indicates that occlusal forces are not necessary
to stimulate cementum deposition
 In posterior teeth, cementum is markedly
thicker on the distal than on the mesial root
surface – indicating relationship to mesial drift
 Cementum like bone is dynamically responsive
and its growth may be stimulated by tensional
forces
 Cementum is thicker in areas exposed to
tensional forces

31.  CEMENTICLES:
 Small foci of calcified tissue, not necessarily true cementum, which lie
free in the PDL of lateral and apical root areas
 Exact cause is unknown
 Mostly represent areas of dystrophic calcification and thus are an eg. of
regressive or degenerative change
 Develop by
 Calcification of epithelial cells – enlarge by further deposition of
calcium salts in the adjacent surrounding connective tissue –
continued peripheral calcification may result in eventual union or
even inclusion of the cementicle in the root cementum or alveolar
bone – pattern of calcification is of a circular lamellated structure.
Only when embedded in the cementum, it may impart a roughened
globular outline to the root surface

32. Ankylosis (Shafer et al, 2006)
Cessation of continued eruption
Anatomic fusion of tooth cementum or dentin with alveolar
bone
Other terms – infraocclusion, secondary retention,
submergence, reimpaction and reinclusion
Pathogenesis is unknown and may be secondary to
disturbances from
Changes in local metabolism
Trauma
Injury
Chemical or thermal irritation
Local failure of bone growth
Abnormal pressure from the tongue

33.  Concrescence (Shafer et al, 2006)
 Form of fusion which occurs after root formation
 Teeth are united by cementum
 Thought to arise as a result of traumatic injury or
crowding of teeth with resorption of interdental bone,
so that 2 roots are in approximate contact and become
fused by deposition of cementum
 May occur before or after tooth eruption
 Diagnosed radiographically
 Extraction of 1 may result in the extraction of the other

34.  Ectopic enamel (Neville et al, 2002)
 Presence of enamel in unusual locations, mainly tooth root
 Enamel pearl :
 Hemispheric structures consisting entirely of enamel or
contain underlying dentin and pulp tissue
 Project from surface of root, more in maxillary molars
 Thought to arise from localized bulging of odontoblastic
layer – bulge may provide prolonged contact between
HERS and developing dentin, triggering induction of
enamel formation
 Majority occur in furcation area or CEJ
 Precludes normal periodontal attachment with
connective tissue and a hemidesmosomal junction
probably exists – less resistant to breakdown, once
separation exists – rapid loss of attachment
 Conducive to plaque retention and inadequate cleansing

35.  Hypercementosis (Neville et al, 2002)
 Nonneoplastic deposition of excessive cementum
that is continuous with the normal radicular
cementum
 Radiographically – thickening or blunting of the
root, surrounded by radiolucent PDL space and
adjacent intact lamina dura
 Also appears in form of spike-like excrescences
called cemental spikes created by either
coalescence of cementicles to the root or
calcification of PDL fibers
 May be isolated, may involve multiple teeth or may
appear as a generalized process
 Premolar teeth involved most frequently
 Occurs predominantly in adulthood and frequency
increases with age

39.  Surface morphology of the tooth wall of periodontal
pockets: (Newman et al,2006)
 The following zones can be found
 Cementum covered by calculus
 Attached plaque, which covers calculus and extends
apically from it to a variable degree, probably 100 to 500
µm
 Zone of unattached plaque that surrounds attached
plaque & extends apically to it
 Zone of attachment of junctional epithelium to tooth -
The extension of this zone, which in normal sulci is
more than 500 µm, is usually reduced in periodontal
pockets to less than 100 µm
 Zone of semidestroyed connective tissue fibers – apical
to junctional epithelium

40.  Attachment of calculus
 Zander in 1953 investigated calculus
attachment and observed four types of
attachment (Shafer et al, 2006)
 Attachment to the secondary cuticle
 Attachment to microscopic irregularities in
the surface of cementum corresponding to
previous location of Sharpey's fibers
 Penetration of microorganisms of calculus
matrix into cementum
 Attachment into areas of cementum
resorption
 Calculocementum: Calculus embedded
deeply in cementum may appear
morphologically similar to cementum
(Newman et al)

41.  Exposure to oral environment
 Bacterial contamination:
 Obvious alterations may occur following exposure of
cementum to the environment of periodontal pocket or oral
cavity
 Root surface wall of periodontal pockets is significant as they
may perpetuate periodontal infection, cause pain and
complicate periodontal treatment
 The root cementum suffers structural, chemical and cytotoxic
changes.

42.  Cervical root resorption :
 Development of large root resorption defect in cervical
region is, most likely, triggered by inflammatory
processes in adjacent connective tissue
 Such resorption generally has an undermining character
 Tooth is resorbed after the alveolar bone – immunity to
resorption has been linked to presence of an uncalcified,
vital layer of precementum on root surface
 Another explanation could be because cementum is
avascular
 Odontoclasts take their origin from bone marrow and cannot
attack the root surface as fast as the osteoclasts reach the
bone surface

44.  Cementum may act to perpetuate the destructive
effects of periodontal disease by acting as a reservoir
for potentially destructive material.
 Aleo et al observed that endotoxin was found to be
present in the cementum of untreated periodontally
involved teeth having 30% or more loss of supporting
bone. The biologic effects of this cementum - bound
endotoxin, studied in vitro concentration as low as 0-
30 mg/ml of culture medium, were effective in
depressing cell proliferation and viability
 When compared to endotoxin form E-coli the
cementum – bound endotoxin was found to be more
toxic. Either biologic activities of endotoxins studied
are not present to an equal degree, or the cementum
bound material contain heat resistant toxic substances
(Aleo et al, 1974)

46.  Kagerer and Grupe suggested the possibility of age
estimation from acellular cementum
 Used mineralized unstained cross sections of
teeth, preferably mandibular central incisors and
third molars
 Authors claimed an accuracy of within 2 or 3 yrs of
chronologic age
 Pathologic state of periodontium may compromise
the precision of ageing
 Hypermineralized bands gave an indication of
events such as pregnancies, skeletal trauma, and
renal disorders

47.  cementum by virtue of its structural and dynamic
qualities, provides tooth attachment and
maintenance of occlusal relationship.
 The discovery of variety of non collagenous
proteins in cementum has opened a new research
area of great therapeutic potential, cementum
specific matrix proteins - cementum derived
growth and/or attachment factors may result in
accelerated wound healing and in controlled
neocementogenesis following periodontal
regenerative surgery.

48.  Orbans’s Oral Histology And Embryology, 12th Edition
 Carranza’s Clinical Periodontology, 10th Edition
 Bosshardt DA and Selvig KA. Dental cementum : the
dynamic tissue covering of the root. Perio 2000, Vol. 13,
1997, 41-75
 Stahl SS. The nature of healthy and diseased root
surfaces. J Periodontol 1975,46(3),156-181
 Warren, Hansen, Swartz and Phillips. Effects of
periodontal disease and of calculus solvents on
microhardness of cementum. J Periodontol 1964