Cementum is the mineralized tissue covering the roots of teeth. It provides anchorage for collagen fibers that attach the tooth to bone. There are different types of cementum based on cellularity and fiber content. Cementum is deposited throughout life to allow for adaptation to occlusion and repair of the root surface. It plays an important role in tooth attachment and acts as a reparative tissue.

1. CEMENTUM
PRESENTED BY
DR JEEVANAND DESHMUKH
DEPARTMENT OF PERIODONTICS

2. DEPARTMENT OF PERIODONTICS

3. CONTENTS
• INTRODUCTION
• DEFINITION
• HISTORY
• PHYSICAL CHARACTERISTICS
• STAGES IN CEMENTUM DEVELOPMENT
• CEMENTOGENESIS
• BIOCHEMICAL COMPOSITION
• CELLS OF CEMENTUM
-CEMENTOCYTES
- CEMENTOCLASTS
• CEMENTOIDS
• ARRANGEMENT OF FIBRILS

4. • CLASSIFICATION
• FUNCTIONS
• CEJ
• CDJ
• INCREMENTAL LINES
• CEMENTUM RESORPTION AND REPAIR
• EXPOSURE OF CEMENTUM TO ORAL ENVIRONMENT
• AGE CHANGES IN CEMENTUM
• ABNORMALITIES OF CEMENTUM
• INFLUENCE OF SYSTEMIC DISESASES ON CEMENTUM
• NEOPLASMS ASSOCIATED WITH CEMENTUM
• APPLIED ASPECTS
• CONCLUSION
• REFERENCES

5. • Cementum is a mineralized connective tissue that covers the roots of the
teeth.
• Derived from Latin “caementum”, quarry stone.
• Component of tooth as well as periodontium.
• Provides anchorage for collagen fibre bundles of periodontal ligament.
• Therefore, root surface area covered by it represents the ground available
for connective tissue attachment.
INTRODUCTION

6. DEFINITION
 Cementum is the calcified, avascular
mesenchymal tissue that forms the outer covering
of the anatomic root. (Carranza)
 Cementum is a mineralized connective tissue, in
part not unlike bone, that covers the entire surface
of anatomical roots of teeth. (Schroeder)
 Cementum is a hard, avascular connective tissue
that covers the root of the teeth. (TenCate’s)

7. • It begins at the cervical portion of the
tooth at the cemento-enamel junction and
continues to the apex.
• Cementum furnishes a medium for the
attachment of collagen fibers that bind
the tooth to surrounding structures

8. HISTORY
Though cementum of the root is critical for periodontal structure and tooth
attachment and function, this tissue was not discovered and characterized on human
teeth until a full century later than enamel and dentin.
Advances in microscopy and histological procedures yielded
the first detailed descriptions of human cementum in 1835 by Jan Purkinje and
Anders Retzius ,who identified acellular and cellular types of cementum, and the
resident cementocytes embedded in the latter.

9. anatomy studies by Richard Owen and
Comparative
others over the latter half of 19th century identified coronal and radicular
cementum varieties across the Reptilian and Mammalia. The functional
importance of cementum was not appreciated until detailed anatomical studies of
the periodontium were performed by G.V. Black and others in the late 19th and
early 20th centuries.

10. PHYSICALCHARACTERSTICS
• HARDNESS: Less than dentin
• COLOUR: Light yellow (Enamel : by lack of luster and darker hue)
• PERMEABILITY:
- Very permeable and permit the diffusion of dyes
- Canaliculi of cellular cementum is contiguous with dentinal tubules in some areas
- Decreases with age

11. THICKNESS:
• Cemental deposition continues throughout life.
• Deposition most rapid in apical areas, where it compensates for tooth
eruption, which itself compensates for attrition.
• Varies form 16-60 micrometer on the coronal half to 150-200 micrometer in
the apical third and furcation.
• Thicker on distal than on mesial surfaces
• Between 11 to 70 years of age thickness increases 3 times

12. PRE-FUNCTIONAL
DEVELOPMENTAL
STAGE
FUNCTIONAL
DEVELOPMENTAL
STAGE
STAGES IN
CEMENTUM
DEVELOPMENT

13. PRE-FUNCTIONAL DEVELOPMENTALSTAGE
• The prefunctional portion of cementum is formed during root development. Since
the formation of human tooth roots occurs over an extended period of time ranging
between 3.75 and 7.75 years for permanent teeth, the prefunctional development of
cementum is an extremely long-lasting process. During this period of time, the
primary distribution of the main cementum varieties is determined for each root.

14. FUNCTIONAL DEVELOPMENTAL STAGE
It commences when the tooth is about to reach the occlusal level, is associated
with the attachment of the root to the surrounding bone and continues
throughout life. It is mainly during the functional development that adaptive
and reparative processes are carried out by the biological responsiveness of
cementum, which in turn, influences the alterations in the distribution and
appearance of the cementum varieties on the root surface with time.

15. The IEE and OEE proliferate downwards as double
layered sheet of flat epithelial cells called HERS. This
induces cells of dental follicle to differentiate into
odontoblasts which secrete organic matrix of predentin
As odontoblsts retreat inwards, they do not
leave behind the odontoblastic processes in
first few layers of dentin.--- hyaline layer
CEMENTOGENESIS

16. Subsequently, break in HERS allowing newly formed
dentin to come in contact with connective tissue cells of
dental follicle
Cells derived from connective tissue are called
cementoblasts which differentiate and form
cementum

17. BIOCHEMICALCOMPOSITION
INORGANIC PORTION (45-50%)
o Mainly Calcium and Phosphate in the form of Hydroxyapatite
o Highest Fluoride content
ORGANIC PORTION (50-55%)
o Collagenous
o Non-Collagenous

18. • Mineral component of cementum is similar as in other calcified tissues i.e.
hydroxyapetite{Ca10(PO4)6(OH)2} with small amount of calcium and
phosphate also present.
• Hydroxyapetite content in cementum (45-50%) is lesser than that in bone
(65%), enamel (97%) or dentin(70%).
• Hydroxyapetite crystals in cementum are average 55 nm wide and 8 nm
thick and is smaller than crystals in enamel.
INORGANICCONTENT

19. Cementum contains 0.5-0.9 % of magnesium ions and its
concentration appears to be lower at surface than in deeper
layers .
Cementum appears to have higher fluoride content as compared
to other hard tissues. Its concentration increases with age and
varies with nutritional status and fluoride supply.
Cementum contains 0.1-0.3 % sulphur as a constituent of
organic matrix.
Trace elements, in particular Cu, Zn and Na can be detected by
electron microprobe analysis.

20. COLLAGENOUSPORTION
• TYPE I (90%) : -Predominant
• TYPE III (5%) : - less cross linked.
-high concentrations during development, repair.
ORGANICCONTENT

21. • TYPE XII : -Afibril associated collagen with triple helix that binds with
type I and non-collagenous proteins
- Related to forces of occlusion.
• OTHERS : -Type V
,VI

22. PROTEOGLYCANS : Heparan sulfate, Chondroitin sulfate ,Keratan sulfate.
*Cell-cell, cell-matrix interactions
UNIQUE TO CEMENTUM:
Cementum derived attachment protein.
Cementum derived growth factor
OSTEOPONTIN: Regulates mineralization
OTHERS: Bone sialoprotein, Alkaline phosphatase, Osteonectin, Dentinsialoprotein
NON- COLLAGENOUSPROTEINS

23. CELLS OF THECEMENTUM
•CEMENTOCYTES
•CEMENTOCLASTS

24. CEMENTOCYTES
incorporated into the cemental
• Cementoblasts
matrix.
• Lie in spaces known as lacunae.
• numerous cell processes or canaliculi, anastomose
with similar processes of the adjacent
cementocytes.
• Directed towards PDL & derive nutrition from
PDL

25. CEMENTOCLASTS:
• Multinucleated cells
• Involved with cemental resorption

26. CEMENTOIDS
• Unmineralized layer of cementum on cemental surface (precementum)
• New layer forms as old calcifies
• 3 to 5 micrometer
• Lined by cementoblasts
• Connective tissue fibers from PDL pass between the cementoblasts
• Embedded portion- Sharpeys fibers

27. ARRANGEMENT OFFIBRILS
• The arrangement of collagen fibers in cementum can be grouped into two:
Extrinsic fiber system
• Consists of principal fibers (sharpeys fibers)
• Mostly arranged at right angles to cementum.
Intrinsic fiber system
• The fibers are dense and irregularly arranged within the cemental matrix.

28. Terminal
portions of the
principal fibers
that insert into
cementum &
bone are
termed as
“Sharpey’s
Fibers”.
Produced by
cells of the
dental follicle
during
development
and later by
periodontal
ligament
fibroblasts
Oriented
perpendicular
to root
surface
5-7microns in
diameter
These have a
principal role
of supporting
the tooth
Mineralized
partially with
unmineralize
d core
extrinsicFIBERS(sharpey’s)

29. INTRINSICFIBERS
Oriented
parallel to
root surface
Produced by
cementoblasts
1-2 microns
in diameter
Uniformly
mineralized
Mainly for
repair

30. Cementum can be classified based on following criteria
Based on location on teeth
• Coronal cementum
• Radicular cementum
Based on cellularity
• Acellular cementum (primary)
• Cellular cementum (secondary)
CLASSIFICATION

31. Based on presence or absence of collagen fibrils in organic matrix
• Fibrillar cementum
• Afibrillar cementum
biochemical
On the basis of location, structure, function, rate of formation,
composition and degree of mineralization cementum can be classified as:-
• Acellular Afibrillar Cementum. (AAC )
• Acellular Extrinsic Fiber Cementum. (AEFC)
• Cellular Mixed Stratified Cementum. (CMSC)
• Cellular Intrinsic Fiber Cementum. (CIFC)
• Intermediate cementum.

32. TYPES OFCEMENTUM
• RADICULAR CEMENTUM
• Derivative of dental follicle, covers the entire dentin of the root from CEJ
to the apex
• It extends partially into apical foramen to line the apical walls of the root
canal
• CORONAL CEMENTUM
• In humans it is restricted to areas of reduced enamel epithelium

33. ACELLULARCEMENTUM
• First formed cementum
• Covers cervial third or half of the root
• Contains sharpey’s fibers and intrinsic fibers but no cells
• Formed before tooth reaches occlusal plane
• Thickness-30-230micrometers

34. CELLULARCEMENTUM
• Formed after tooth reaches occlusal plane
• More irregular
• Contains cementocytes in lacunae communicating with each other through
anastomosing canaliculi
• Sharpey’s fibers occupy smaller portion. Intrinsic fibers are more in
proportion.

35. Acellular cementum showing
incremental lines running
Parallel to long axis of tooth.
Cellular cementum
Showing cementocytes
within lacunae.

36. ACELLULAR AFIBRILLARCEMENTUM
• It is a mineralized ground substance, containing no cells and is devoid of extrinsic
and intrinsic collagen fibres.
• It is a product of cementoblasts.
• Found as coronal cementum at dentinoenamel junction.
• Thickness of 1-15micrometers.

37. • Acellular afibrillar cementum is deposited as isolated patches over minor areas of
enamel and dentin.
• Cementum islands represent isolated patches of acellular afibrillar cementum
deposited on the enamel over small areas of the crown just coronal to the
cementoenamel junction.
• Cementum spurs are found around the cementoenamel junction, where they
cover minor areas of the enamel and the adjacent dentin of the root.

38. ACELLULAR-EXTRINSIC FIBRECEMENTUM
• Extends from cervical margin to apical one third
• It is a product of fibroblasts and cementoblasts.
• Sharpey’s fibres are seen perpendicular to surface of cementum
• Composed almost entirely of densely packed collagen fibers and lacks
cells.
• Approximately 30,000 fibres/ mm2 insert in it indicates its significant
function in tooth anchorage to surrounding bone.

39. • Since this type of cementum is formed slowly and regularly
incremental lines are placed parallel to the surface and closer
together than in cellular cementum.
• Main function of this cementum is anchorage.
• Thickness ranges between 30-230 µm

40. A thin layer of AEFC with
densely packed extrinsic fibers
cover the peripheral dentin.
Cementoblasts and fibroblasts
can be seen adjacent to
cementum
Arrangement of Collagen
bundles in AEFC

41. CELLULAR INTRINSIC FIBRECEMENTUM
• Contains cells, but no extrinsic collagen fibers.
fills the resorption
• Formed on the root surface.
• Secreted by cementoblasts,
lacunae.
• Mainly involved in adaptation and repair of cementum.
• Less mineralized

42. • Although it has no important function in tooth attachment, it
has important function as adaptation tissue that brings and
maintains tooth in its proper position.
• CIFC has capacity to repair a resorption lacunae in a reasonable
amount of time due to its capacity to grow much faster than any
other cementum type

43. CELLULAR MIXED STRATIFIEDCEMENTUM
• Extrinsic and intrinsic fibres and cells, forms the bulk of secondary
cementum
• Co- product of fibroblasts and cementoblasts
• Apical third of roots and furcations
• Thickness varies from 100-1000 micrometer
• Also involved in adaptation and repair of cementum.

44. Structure of CMSC which in contrast to AEFC,
contains cells and intrinsic fibers
Cementocytes [black cells] reside in lacunae in CMSC
or CIFC

45. INTERMEDIATECEMENTUM
• Poorly defined zone near CDJ separating cementum from dentin, which doesnot
exhibit characteristic feature of either dentin or cementum.
• It appears hyaline(structureless)and so its also called hyaline layer
• This layer represents area where HERS cells become trapped in a rapidly
deposited dentin or cementum matrix giving rise to intermediate layer
• Usually occurs in the apical half of roots of molars and premolars.

46. • The exact nature of this layer is still controversial. This layer
is considered to be of dentinal origin
• Sometimes it’s a continuous layer or it may be also found
only in isolated areas. The probable function might be to
seal the sensitive root dentin.

47. FUNCTIONS OF CEMENTUM
ANCHORAGE
ADAPTATION
REPAIR

48. anchorage
• It furnish a medium for the attachment of collagen fibers that bind the
tooth to alveolar bone
• Since collagen fibres of PDL cannot be incorporated into dentin, a
connective tissue attachment to tooth is not possible without cementum

49. adaptation
• Cementum makes functional adaptation of teeth possible
• The continuous deposition of cementum is of considerable functional
importance.
• Continuous deposition of cementum in apical area compensates for loss of
tooth substance from occlusal wear.
• As the most superficial layer of cementum ages, a new layer of cementum
must be deposited to keep the attachment apparatus intact.
• This process also serves to maintain the width of the periodontal ligament
space at the apex of the root.

50. REPAIR
• Cementum serves as a major reparative tissue for root surfaces
• Damage to roots such as fractures and resorptions can be repaired by
deposition of new cementum
• Cementum forms during repair resembles cellular cementum because it
forms faster but it has a wider cementoid zone and the apatite crystals are
smaller.

51. cEMENTO-ENAMELJUNCTION
• 1) In approximately 60% of teeth cementum overlapping the cervical end
of enamel for a very narrow area at the CEJ . This occurs as a result of
premature degeneration or retraction of the reduced enamel epithelium at
the cervical region of enamel . This allows for the adjacent mesenchymal
cells to invade and intervene between enamel and its covering epithelium .
The mesenchymal cells differentiate into cementoblasts and deposit
cementum on enamel surface .

52. 2)30% of all teeth, cementum meets the cervical end of enamel in a knife or
edge-to-edge pattern .
3)In approximately 10% of teeth, cementum does not meet enamel where a
zone of root dentin appears devoid of cementum . This can result in dental
hypersensitivity as the gingiva recedes exposing the underlying root dentin
4)In some rare cases, a fourth type of cemento-enamel junction is seen.In
these cases, the enamel overlaps the cementum

53. TYPES OF CEJ
CEMENTUM OVERLAPS
ENAMEL 60-65%
BUTT JOINT 30% DO NOT MEET
5-10%

54. CEMENTO-DENTINALJUNCTION
• The terminal apical area of the cementum where it joins the internal root canal
dentin.
• The CDJ is a wide zone containing large quantities of collagen associated with
GAGs resulting in incresed water content which contributes to stiffness. This
reduction in mechanical property helps to redistribute occlusal loads to alveolar
bone.
• 2 to 3 micrometer’s wide
• Stable with age

55. The dentin surface upon
which cementum is deposited
is relatively smooth in
permanent teeth
The cementodentinal
junction in deciduous teeth,
however, is sometimes
scalloped

56. INCREMENTALLINES
• Called lines of salter seen during the process of cementogenesis.
• The period of rests are associated with these lines
• These lines are closer in acellular cementum as this is formed slowly
• Whereas in cellular cementum, theses lines are widely spaced because of
increased rate of formation.

58. CEMENTALRESORPTION
• Local causes: Trauma from occlusion, orthodontic movement,
cysts and tumors, periapical and periodontal disease.
• Systemic causes: Calcium deficiency, Hypothyroidism, Pagets
disease.
• In severe cases, resorption may continue into the dentin.

59. • MICROSCOPICALLY: Bay like concavities in the root surface
• Multinucleated Giant cells and large mononuclear macrophages found.
• Not continuous and is alternated by periods of repair and deposition .
• Newly deposited cementum demarcated from old by deeply staining
irregular line- Reversal line
• Reversal line- Has few collagen fibrils and highly accumulated
proteoglycans with mucopolysaccharides.

60. CEMENTALREPAIR
• Remodelling of cementum requies the presence of viable connective tissue
• This can occur in vital or non vital teeth.
• In most cases of repair, there is a tendency to reestablish the former outline of root
surface. This is called anatomic repair.

61. • And if only a thin layer of cementum is deposited on a deep resorption surface,
root ouline is not constructed and bay like recess remains. In such areas,
sometimes the periodontal space is restored to its normal width by formation of
a bony projection so that a proper functional relationship will result. The outline
of alveolar bone in these cases follow that of root surface. This change is called
functional repair.

62. EXPOSURE OF CEMENTUM TO ORALENVIRONMENT
• Cementum becomes exposed to the oral environment in case of gingival
recession and as a result of loss of attachment in pocket formation.
• The cementum is sufficiently permeable to be penetrated in these cases by
organic substances, inorganic ions and bacteria.
• Bacterial invasion of the cementum occurs frequently in periodontal disease.

63. AGE CHANGES INCEMENTUM
continuous deposition
• Cementum formation continues throughout life and is deposited at a linear rate.
• More cementum is deposited apically than cervically.
• There is a tendency for cementum to reduce root surface concavities thus thicker
layers may form in root surface grooves and in furcation areas.

64. Abnormalities of
CEMENTUM

65. HYPERCEMENTOSIS
Hypercementosis is a non neoplastic deposition of excessive Cementum
that is continuous with the normal radicular cementum.
Factors Associated with Hypercementosis
LOCALFACTORS
• Abnormal occlusal trauma
• Adjacent inflammation
• Unopposed teeth [e.g., impacted, embedded, without antagonist)

66. SYSTEMIC FACTORS
• Neoplastic and non neoplastic conditions including benign
cementoblastoma, cementifying fibroma, cemental dysplasia
• Acromegaly and pituitary gigantism
• Paget's disease of bone
• Rheumatic fever
• Thyroid goiter

67. CLINICALFEATURES:
• Hypercementosis occurs predominantly in adulthood, and the
frequency increases with age.
• Its occurrence has been reported in younger patients, and
many of these cases demonstrate a familial clustering,
suggesting hereditary influence.
RADIOGRAPHIC FEATURE:
• Radiographically, affected teeth demonstrate a thickening or
blunting of the root. but the exact amount of increased
cementum often is difficult to ascertain .
• Radiolucent shadow of PDL and radiopaque lamina dura
always seen
NO TREATMENT REQUIRED

68. Description and Location
• Cemental tears or separations can occur either as a split within the
cementum that follows one of its incremental lines or more commonly as a
complete separation along the cemento-dentinal border.
or be completely
• The cemental fragment can remain partially attached
detached from the root surface.
CEMENTALTEARS

70. ANKYLOSIS
• Fusion of cementum and alveolar bone with obliterated PDL
replantation, occlusal
• Occurs in teeth with cemental resorption
• After periodontal inflammation, tooth
trauma.
• Results in resorption of root and its gradual replacement by bone.
• Lack physiological mobility, metallic percussion
• No proprioception because pressure receptors in periodontal
ligament are deleted or not function correctly.

71. Radiographically:
 Resorption lacunae are filled with bone.
 Periodontal ligament space is missing.
Treatment:
 No predictable treatment can be suggested.
 Treatment modalities range from a conservative approach,such as resotorative
intervention to surgical extraction of affected tooth.

72. CEMENTICLES
• Abnormal, calcified bodies in the periodontal ligament
• It has been postulated that they originate from foci of degenerating cellsor
epithelial rest cells
• Generally less than 0.5mm in diameter
• Types
Free cementicles.
Sessile or attached cementicles.
Interstitial cementicles
• As the cementum thickens with advancing age, it may envelop these bodies.

73. • If some HERS cells remain attached to forming root surface,
they can produce focal deposits of enamel like structures
called ENAMEL PEARLS.
ENAMELPEARLS

74. CONCRESCENCE
• Fusion of teeth by fusion of cementum, max.
molars
• Traumatic injury or crowding of teeth in the
area during the apposition and maturation
stage of development may be the cause.
• Difficulty in extraction

75. INFLUENCE OF SYSTEMIC DISEASESON
CEMENTUM

76. HYPOPHOSPHATASIA
• Hypophosphatasia is a rare metabolic bone disease that is characterized by
a deficiency of alkaline phosphatase.
• One of the first presenting signs of hypophosphatasia may be the
premature loss of the primary teeth presumably caused by a lack of
cementum on the root surfaces.
• The histopathologic examination of either a primary or permanent tooth
that has been exfoliated from an affected patient often shows an absence
or a marked reduction of cementum that covers the root's surface.
TREATMENT:
• The treatment of hypophosphatasia is essentially symptomatic because the
lack of alkaline phosphatase cannot be corrected

77. PAGETSDISEASE
• Paget’s disease is characterized by enhanced resorption of bone.
• Etiology: viral infection, inflammatory cause, autoimmune, connective tissue and
vascular disorder.
CLINICAL FEATURES:
• Middle age and both males and females are affected.
• Involvement of facial bone.
• MAXILLA- progressive enlargement, alveolar ridge widened, palate flattened,
tooth become loosened.
• MANDIBLE: findings are similar but not as severe as maxilla.

78. RADIOGRAPHIC FINDING:
• Cotton wool appearance of paget’s bone
• GENERALISED HYPERCEMENTOSIS of the tooth seen.
CHARACTERISTIC HISTOLOGIC FEATURE:
• Jigsaw or mosaic pattern
TREATMENT:
• No specific treatment

79. HYPERPITUITARISM
•
•
• Gigantism is the childhood version of growth hormone excess and is characterized by
the general symmetrical overgrowth of the body parts.
Prognathic mandible, frontal bossing, dental malocclusion, and interdental spacing
are the other features.
• Intraoral radiograph may show hypercementosis of the roots.
• Acromegaly is characterized by an acquired progressive somatic disfigurement, mainly
involving the face and extremities, but also many other organs, that are associated with
systemic manifestations.
Dental radiograph may demonstrate large pulp chambers and excessive deposition
of cementum on the roots

80. NEOPLASMS ASSOCIATEDWITH
CEMENTUM

81. CEMENTOBLASTOMA
• The benign cementoblastoma is probably a true neoplasm of functional
cementoblasts which form a large mass of cementum or cementum-like tissue on
the tooth root.
Clinical features
• Under age of 25 years, mostly in mandible, 1st PM
• Slow growing, may cause expansion of cortical plates
Radiographically, well circumscribed dense radioopaque mass often surrounded
by a thin ,uniform radiolucent line.
Treatment :
• Extraction of tooth though pulp is vital as it might cause expansion of jaws

82. CEMENTIFYINGFIBROMA
• The neoplasm is composed of fibrous tissue that contains a variable mixture of
bony trabeculae, cementum like spherules or both.
• origin of these tumors is odontogenic or from periodontal ligament.
CLINICALFEATURE:
• 3RD and4TH decades, female predilection,mandi.PM and molar
• seldom cause any symptoms and are detected only on radiographic examination.
Radiographically, the lesion most often is well defined and unilocular
• it may appear completely radiolucent, or more often varying degrees of radiopacity
• TREATMENT: Enucleation of the tumor

83. APPLIEDASPECTS

84. • Zander and Hurzeler(1958) stated that cementum is a better age estimating tissue
than others
• Incremental lines in cementum can be used as most reliable age marker than any
other morphological or histological traits in skeleton
• Evaluation of annual incremental lines of dental cementum is one of potentially
valuable methods for biological age estimation in forensic anthropology and
digitalized visual analysis system enhances the count and provides better results.
(Bojarun et al,2003)

85. CONCLUSION

86. • Clinical Periodontology and Implant dentistry- Lindhe 4th Edition
• Carranza’s Clinical Periodontology- 10th Edition
• Orban’s oral histology and embryology- 12th Edition
• TenCate’s Oral histology- 6th edition
• PERIO 2000 - Dental cementum: the dynamic tissue covering of the root.
-Dieterd . Bosshard &t Knuta . Selvig
REFERENCES