Cementum / rotary endodontics courses

INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

 Introduction.
 Development of Cementum (Cementogenesis).
 Physical Characteristics.
 Composition.
 Microscopic Structure.
 Types of junctions & its clinical significance.
 Age Changes.
 Changes in Cementum during Pocket Formation.
 Local Conditions Leading to Changes in the Cementum.
 Systemic Conditions Leading to Changes in the Cementum.
 Neoplasms & Cemental Aberrations.
 Current Concepts.
 Conclusion.

Cementum is a
highly specialized
form of
mesenchymal
connective tissue,
which is hard,
avascular & forms
the outer covering
of the anatomic
roots of teeth.
First described in
1835, it has till
recently, remained
a poorly defined
tissue at the cellular
& molecular level.
It is unique in that
it is avascular,
devoid of
innervation, has no
direct blood supply
& lymph drainage.

Formation of Cementum can be subdivided into:-
•where the Cementum is formed
during root development.
Pre - functional
development
stage
• which takes place when the
tooth is about to reach the
occlusal level & continues
throughout life.
Functional
development
stage

Cementum formation
in developing teeth is
preceded by the
deposition of dentin
along the inner aspect
of Hertwig’s
Epithelial Root
Sheath (HERS).
Once the 1st layer of
radicular mantle dentin
has been laid down by
maturing odontoblasts &
before mineralization of
dentin reaches the inner
epithelial cells, HERS
becomes fragmented.
Cells from the dental
follicle then penetrate
the HERS & occupy
the area next to the
predentin.
This direct contact of dentin
with the connective tissue of
the dental follicle, stimulates
the undifferentiated ecto -
mesenchymal cells to
differentiate into
cementoblasts, which begin
to produce collagen fibers
The first Cementum
deposited on the
superficial layer of
mantle dentin(hyaline
layer)contains enamel
matrix proteins.

The outermost layer of cemental matrix which persists
for life of the tooth.
Unmineralized & begins initially at the CEJ.
Located between the calcified layer & cementogenic
/cementoblastic layer.
3-5µm thick in width; about a micron at the apex.
Produces a compatible environment for
cementoblasts
Prevents cemental Resorption.
Attaches tooth to the surrounding bone.

Begins in the depth
of the pre -
cementum.
Fine hydroxyapatite
crystals deposited
initially between &
later on within the
collagen fibrils, with
the crystals
generally directed
parallel to the
direction of the
collagen fibrils.
Although the
additional cementum
is laid down
throughout life, the
mineral content of
this tissue once
formed, does not
seem to change
significantly with
age.

Functions related to
Cementogenesis :-
 Promotes cell differentiation
& subsequently
cementogenesis during
development &
regeneration.
 PDGF alone / with IGF
promotes cementum
formation by altering cell
cycle activities.
 Promotes cell proliferation,
migration & angiogenesis -
key events for the formation
& regeneration of
periodontal tissues.
Proteins / factors
 Growth factors :-
 TGF- β super
family.
 PDGF & IGF.
 FbGF .

 Adhesion molecules:-
 Bone sialoprotein.
 Osteopontin.
 Epithelial / Enamel
like factors :-
 (PTH related protein /
EMD).
 Promotes adhesion of
selected cells to forming
root & aids in
mineralization.
 Regulates events of crystal
growth.
 Epithelial - mesenchymal
interaction promoting
follicle cells along
cementoblast pathway,
PDL repair &
regeneration.

 Collagens:-
 Gla proteins:-
 Matrix Gla proteins.
 Bone Gla protein.
 Collagens I & III play a key role in
regulating periodontal tissues
during repair & regeneration.
 Collagen XII - assists in
maintaining PDL space versus
continuous formation of
cementum.
 Play a significant role in
preventing ectopic calcification.
 Marker for cells associated with
mineralization(osteoblasts,

Transcription factors :-
Other factors :-
 Alkaline phosphatase.
 Proteoglycans.
 MMPs.
 CbfaI & Osterix are the
master switches for
differentiation of
osteoblasts.
 Formation of
mineralized tissues.
 Promoting / inhibiting
differentiation of cells of
the periodontium.

 Highly calcified connective tissue covering the
surface of the teeth from the CEJ to the apex & also
lines apex of the root canal.
 Site through which the connective tissue apparatus
of the PDL. ligament fibers are inserted into the
tooth.

 Hardness of the fully mineralized cementum is <
that of dentin.
 Light yellow in color & can be distinguished from
enamel by its lack of lusture & darker hue; but
lighter than dentin.

 Cementum formation is most rapid in the apical
region, where it compensates for tooth eruption,
which itself compensates for attrition.
 Permeability:- both Cellular & Acellular
Cementum are permeable to a variety of
materials, with that of Cellular being > Acellular
Cementum.

 In the Cellular Cementum, the canaliculi in some
areas are contiguous with the dentinal tubules.
 Permeability of cementum ↓ces with age.
- ( Blayney, J. R.et al., 1941).

 Biochemical studies have shown that the
composition of cementum is similar to that of bone.
 On a dry weight basis, cementum has :-
 Organic substances & water :- 50 - 55%.
 Type I collagen (90%) of the matrix.
 Protein polysaccharides (proteoglycans).
 Glycoproteins & phosphoproteins.
 Inorganic substances & water :- 45 - 50%.

Primarily consists of :-
 Type I collagen which is known to promote cell
attachment & serves as a critical molecule for
maintaining the integrity of both soft & hard
connective tissue during development as well as
repair.
 Type III collagen(<5%) :- found in high conc.
during development, repair & regeneration.

 Type XII collagen fibrils binding to type I collagen
& also to non-collagenous proteins.
 Also, trace amounts of Type V, VI & XIV found in
mature organic matrix derived from Sharpey’s fibers
& embedded at right angles / obliquely into the root
surface (extrinsic fibers)- responsible for root
anchorage & produced by fibroblasts of PDL.

 In contrast, those derived from cementoblasts, run
parallel to the root surface & at right angles to the
extrinsic fibers & called ‘Intrinsic fibers’.

 Rich in glycoproteins, phosphoproteins & a variety
of proteins like those found in bone – BSP,
Osteopontin, Osteonectin, Osteocalcin,
Proteolipids, Dentin matrix protein – 1 & several
growth factors including IGF & Cementum
Attachment / Adhesion Molecule.
 BSP & Osteopontin are predominant non –
collagenous glycoproteins which bind tightly to the
collagen matrix & have cell attachment properties,
taking part in the mineralization process during early
tooth development & contribute to cementoblast
progenitor cells. www.indiandentalacademy.com

 2 other glycoproteins – fibronectin & tenascin
are widely distributed, binding cells to the
components of the ECM.
 Other multifunctional proteins such as laminin &
fibronectin act as chemoattractants in addition to
aiding adhesion.
 Together with proteins like tenascin & BSP,
osteopontin & osteocalcin appear to be involved in
the mineralization process.

Some cementum specific proteins are also present
such as CAP (Parker, T., et al, 1996) as a mitogenic
factor (Narayan, S., et al, 1991) CEM-1 (Slavkin
H. C., et al, 1989).
Cementoblasts & cementocytes produce high levels of
the GLUT-1–monosaccharide transporter, which
may play a role in cementogenesis( biomarker to
differentiate between cementoblastic & osteoblastic
lineage).-Koike, H. et al., (2005); Somerman, et al.,
(1987).

 Enamel related proteins have also been detected in
cementum.
 Biochemical analysis have revealed chondroitin 4 –
sulphate, chondroitin-6-sulphate, hyaluronic acid,
dermatan sulphate, in cementum.
 Enzyme alkaline phosphate is thought to participate
in cementum mineralization .
- Beensten, (1989) .

INORGANIC
MATERIAL (45-50%):
• Cementum is less mineralized than root dentin.
• Acellular extrinsic fiber cementum is comparatively more
mineralized because of uncalcified spaces such as lacunae &
uncalcified core of Sharpey’s fibers. & also because it is
slowly formed which allows longer & direct contact with
tissue fluids.
HYDROXYAPATITE
CRYSTALS:
• Like in all other calcified tissues, the principle component is
hydroxyapatite crystals, which are aggregates of calcium &
phosphate salts derived from tissue fluids & are arranged
parallel to the long axis of the collagen fibrils.
- Selvig, (1969).

MAGNESIUM:-
It is present in concentrations varying
from 0.5-0.9%.
0.5% is seen at the surface while 0.9%
is seen at cemento-enamel junction.
An important aspect is that
magnesium is the first element to leach
out in early carious lesions but is not
significantly reabsorbed during
remineralization;
.
FLUORIDE:-
It is an important constituent of
cementum. Its concentration is
highest in cementum amongst
all calcified tissues. (0.9%.)
Fluoride level in acellular
cementum is > of
cellular cementum.

SULFUR:-
present in varying
concentrations
ranging from 0.1
to 3%(higher in
areas that are
exposed to the
oral cavity.)
CARBONATES CITRATES

CEMENTOBLASTS
Origin :-
 Are cemento – progenitor cells
synthesising collagen & protein
polysaccharide (proteoglycans) which
make up the organic matrix of
cementum.
 Arise from the dental follicle proper
which is ectomesenchymal in origin
(Tencate, 1971) - a derivative of the
cranial neural crest.
 Recent ultra-structural studies &
immunohistochemical studies support
the hypothesis that the cementoblasts
originate from the cells of HERS
when they undergo an epithelial
mesenchymal transformation.
Differentiation:-
 The fibrogenic cells of the dental
follicle are either fibroblasts /
mesenchymal cells.
 Tend to become differentiated into
cementoblasts as they invade, approach
& align themselves along the external
border of the dentin to form
cementogenic layer.
 Form a single / multicellular layer.
 The components of multilayered cells
are more flattened than that of single
cells
 Contain mitochondria, an extensive
network of surrounding well developed
Golgi system & ribosomes.
 These features of cementum are similar
to those of other collagenwww.indiandentalacademy.com

 The apical 1/2 or 1/3rdof the root is covered with
cellular cementum.
 The number of cementocytes in the matrix is
variable.
 Cementum that is formed rapidly generally
possesses wider lamellae & more cementocytes.
 In the apical 1/3rd,cementoblasts trapped in rapidly
calcifying cemental matrix, later, differentiate into
cementocytes.

 These locate in spaces termed lacunae & have
numerous cytoplasmic processes coursing in
canaliculi, that are preferentially directed towards
the periodontal ligament.
 This is how cementocytes derive their nutrition from
periodontal ligament & contribute to the vitality of
this mineralized tissue.

 While adjacent canaliculi of neighboring
cells communicate frequently, the
processes remain independent.
 Thus, the metabolites progress mostly
by diffusion through the canaliculi of
cellular cementum.

 They are multinucleated giant cells, which are
indistinguishable from osteoclasts.
 Responsible for root resorption that leads to primary
teeth exfoliation & also in the permanent dentition
in mesial surfaces in compliance with mesial
migration & may occur due to occlusal trauma &
orthodontic therapy.

Types of
Cementum
Embryologically Primary & Secondary
According to location
on teeth ( Kronfield
1928).
- Radicular cementum- found on root
surfaces.
- Coronal Cementum to Cementum that
forms on the enamel covering the crown.
On the basis of
cellularity (Gottlieb
1942).
- Acellular / Primary Cementum.
- Cellular / Secondary Cementum.
Schroder(1986)
classified cementum x 5
subtypes based on
cellularity &
organisation of collagen
fibres into
- Acellular afibrillar cementum.
- Acelluar extrinsic fiber cementum.
- Acellular intrinsic fiber cementum.
- Cellular intrinsic fiber cementum.
- Cellular mixed stratified cementum
Based on the origin of
the collagen matrix
- Extrinsic.
- Intrinsic.
- Mixed.
Depending on the
location & patterning
- Intermediate.
- Mixed stratified cementum.

 Refers to cementum lacking embedded cells.
 First formed cementum, covers approximately the
cervical ⅓ or ½ of the root & does not contain cells
(i.e., cells that form it remain on its surface).

 Formed before tooth reaches the occlusal plane.
 Thickness ranges from 30 – 230µm.
- Schroeder, (1986).
 Sharpey’s fibers make up most of the structure of
acellular cementum, which has a principle role in
supporting the tooth.

 Most fibers are inserted at angles into the root
surface, are completely calcified with mineral
crystals oriented parallel to the fibrils, except in a 10
– 50 µm wide zone near the CEJ, where they are
only partially calcified.
 Also contains intrinsic collagen fibrils that are
calcified and are irregularly arranged / parallel to the
surface.
- Schroder, (1980).

 Is formed after tooth reaches the
occlusal plane.
 Is more irregular & contain cells
(cementocytes) in individual spaces
(lacunae).
 Less calcified than acellular cementum.

 Sharpey’s fibers occupy a smaller
portion of cellular cementum & are
separated by other fibers that are
arranged either parallel to the root
surface or at random.
 Thickness of cellular cementum is
greater than acellular.

 Both cellular & acellular cementum are arranged in
lamellae separated by incremental lines, parallel to
the long axis of the root.
 These lines represent rest periods in cementum
formation & are more mineralized than the adjacent
cementum (Romanos 1992) & termed the
‘Incremental lines of Salter’.

Acellular
Cementum
Cellular
Cementum
Formation Forms before tooth reaches
occlusal plane
After tooth reaches occlusal
plane
Cells Does not contain any cells Contains cementocytes
Location Coronal portion of root Apical portion of root
Rate of
formation
Slow Rapid
Incremental
lines
More Sparse

Acellular
Cementum
Cellular
Cementum
Function Forms after regenerative
periodontal surgical procedure
Contributes to the
length of the root during
growth
Calcification More calcified Less calcified
Sharpey’s fibers More Less
Regularity of
fibers
Regular Irregular
Thickness 20 – 50µm near the cervical
region &150 – 200µm near the
apex.
Thickness of 1 – several
mm.

• Contains neither cells, nor extrinsic / intrinsic
fibers, apart from a mineralized ground
substance.
• It is a product of cementoblasts, found deposited
on the enamel over small areas of the dental
crown just coronal to the CEJ.
• Thickness is about 1 - 15 µm.

Composed almost entirely of densely packed bundle of
Sharpey's fiber and no cells.
 A product of fibroblasts and cementoblasts,
 found on the cervical ⅓ of roots, but may extend
further apically..
 Cementoblasts that produce AEFC differentiate in
close proximity to the advancing root edge.


 Thickness is between about 30 - 230 µm &
continues to grow in thickness (@ 1.5 - 3 µm / year)
as long as the adjacent periodontal ligament remains
undisturbed.

 During root development, the first formed
cementoblasts align along the newly formed, but not
yet mineralized, mantle dentin surface & exhibit
fibroblastic characteristics.
 Deposit collagen fibrils within it so that dentin &
cementum fibers intermingle.

 Initially AEFC consists of mineralized layer with a
short fringe of collagen fibers implanted
perpendicular to the root surface.
 Cementoblasts then migrate away from the surface
but continue to deposit collagen so that a fine fiber
bundle lengthens & thickens.

 These cells also secrete non – collagenous matrix
proteins that fill in the spaces between the collagen
fibers.
 Although this cementum is classified as AEFC, its
initial part should be classified instead as having
intrinsic fibers, as the collagen matrix of the first
formed cementum results from cementum –
associated cells & is elaborated before the
periodontal ligament forms( local / intrinsic.)

Only after the first 15 – 20 µm have formed, the
intrinsic fibrous fringe become connected to the
PDL. fiber bundles.
The overall degree of mineralization of this cementum
is about 45 – 60%.
AEFC has the potential to adapt to functionally
dictated alterations such as mesial tooth drift.

 Contains both collagen fibers &
calcified matrix.
 It is the co – product of cementoblasts &
fibroblasts and consists of both extrinsic
& intrinsic fibers.

 Appears primarily in the apical third of the roots &
in furcation areas.
 Consists of AEFC and CIFC that alternate &
appear to be deposited in irregular sequence upon
one another.
- Schroeder, (1993).
 Deposited @ 0.1 – 0.5 µm / year.

 Contains cells but no extrinsic (Sharpey's) fibers.
 Once the tooth is in occlusion, a more rapidly
formed & less mineralized variety of cementum,
(CIFC) is deposited on unmineralized dentin surface
near the advancing root edge.

 Formed by cementoblasts & fills resorption lacunae
(resorptive cementum.)
 Can easily repair a resorptive defect of the root due
to its capacity to grow faster than any other form of
cementum.

 An acellular variant of cellular intrinsic fiber
cementum that is also deposited during adaptive
responses to external forces (i.e.,) slow deposition
rate so that cells are not engulfed in their matrix &
that forms without leaving cells behind.
- Bosshardt & Schroder, (1990)
.

 In the light microscope, CIFC is identified easily because of the
inclusion of cementocytes within lacunae with processes
directed towards the tooth surface, laminated structure &
presence of cementoid on its surface.
 Fine, densely packed intrinsic fibers running parallel to the root
surface & larger, haphazardly incorporated extrinsic fibers
running at right angles to the root surface.
 Cellular intrinsic fiber cementum is initially deposited on root
surface areas where no acellular extrinsic fiber cementum has
been laid down on the dentin (furcation and on the apical root
portions).

 Cementum deposition is a continuous
process that proceeds at varying rates
throughout life.
 The thickness on the coronal ½ of the
root varies from 16 µm in the apical
third to furcations - 150µm – 200µm.

 It is thicker on the distal surface than on the mesial,
consequent to functional stimulation from mesial
drift over time(Polson.A et al 1990).
 Is more rapid in the apical region where it
compensates for attrition (passive eruption).
 Between the ages of 11 & 70, the average thickness
↑ 3 fold, with the greatest ↑ in the apical area.

Functions of Cementum….
Anchorage:-
the primary
function is
the
formation
of a
medium for
the
attachment
of collagen
fibers that
bind the
tooth to the
alveolar
bone.
Apical
cementogen
esis
compensate
for the
attrition of
enamel,
thereby
maintaining
occlusal
functional
relationship
.
Assists in the
maintenance
of the width
of the
periodontal
ligament by
cementogenic
activity.
Provides for
fiber
reattachment
& relocation
consequent to
mesial
drifting of
teeth.
Serves as a
major
reparative
tissue foll.
root
surface
damages
such as
fracture &
resorption
by
formation
of new
cementum.
Protects
underlying
dentin.

 After differentiation, cementoblats extend numerous
tiny processes at the beginning of their maturation
on the root surface.
 They encounter numerous tiny cytoplasmic
processes in the loosely arranged but not yet
mineralized dentinal matrix, leading eventually to
an intimate interdigitation of the two different fibril
populations.

 The mineralization in dentin does not reach the
future dentino – enamel junction until the dentinal
matrix is covered with the collagen fibrils
of Cementum.
 Recent studies by Inamoto, et al., have suggested
that mucopolysaccaharides might have an important
role in the formation of the CD junction.

Relation of Cementum to Enamel at the Cemento –
Enamel Junction (CEJ) ‘OMG’ rule---
 In about 60% of the teeth
,cementum OVERLAPS enamel
(enamel degenerates for a short
distance at its cervical termination)
 In about 30% of the teeth,
cementum just MEETS enamel.
 In about 10% of the teeth ,there is
a small GAP, where cementum &
enamel fail to meet.

 Cementum formation continues throughout life unless
disturbed by periapical / periodontal pathology.
 More cementum is deposited apically than cervically.
 Thicker layers may form in the root surface grooves & in
furcations.
 In the cementum of impacted teeth, sharpey’s fibres may
be nearly completely absent & may be built up mainly of
intrinsic fibres arranged parallel to the root surface.

 Great variations in the width of incremental layers
indicates that the rate of formation varies from time
to time.
 Non – functional & impacted teeth appear to have
thicker cementum than functional teeth.

 The distribution of cementum on impacted teeth
indicates that occlusal forces are not necessary to
stimulate cementum deposition.
 In the posterior teeth, cementum deposition is
thicker on the distal side than on the mesial,
indicating a relationship to mesial drift
- Polson, A. (1990).

 Extremely common.
 Although physiological root resorption is a normal
phenomenon of deciduous teeth during tooth
shedding, permanent teeth do not generally
undergo physiologic resorption.

 The cementum of erupted as well as unerrupted
teeth is subject to resorption.
 The resorptive changes may be of microscopic
proportion / sufficiently extensive to be visible on a
radiograph.

 Cementum resorption is not necessarily continuous
& may alternate with periods of repair & deposition
of new cementum.
 Newly formed cementum is demarcated from the
root by a deeply staining irregular line termed the
Reversal line (contains a few collagen fibrils &
proteoglycans) & delineates the border of the
previous resorption.

 Is the fusion of the cementum & alveolar bone with
obliteration of PDL.
 Occurs in teeth with cemental resorption, which
suggests that it may represent a form of abnormal
repair.
 May develop after chronic periapical pathology, tooth
replantation, occlusal trauma & around embedded
teeth.

 Occurs most frequently in the primary
dentition ( McNamara ,et al., 2000).
 Results in resorption of root & its
gradual replacement by bone tissue. For
this reason reimplanted teeth that
ankylose will loose their roots after 4 – 5
years & will be exfoliated.

 .Clinically, ankylosed teeth lack physiologic
mobility of normal teeth which is one of the first
diagnostic sign for ankylotic resorption. These teeth
usually have a special metallic percussion sound & if
the ankylotic process continues, they will be in infra
- occlusion.
 Proprioception, physiologic drifting, eruption as
well as ability of teeth & periodontium to adapt to
altered force levels or direction of force is greatly
reduced.

 Cementum becomes exposed to oral environment in
gingival recession & as a result of loss of
attachment in pocket formation.
 Cementum is sufficiently permeable to be
penetrated by organic substances, inorganic ions &
bacteria, leading to hypersensitivity to thermal
changes / tactile stimulation, root caries, etc...
sometimes resulting in pulpal pathology.

 Areas of Increased Mineralization: -
Selvig, (1966) as a result of exchange on
exposure to the oral cavity, of minerals & organic
component at the cementum saliva interface.
 Areas of Demineralization:-
Exposure to oral fluids & bacterial plaque
results in proteolysis of the embedded Sharpey’s
fibres, leading to softening of the cementum, which
undergoes fragmentation & cavitation (root caries)
→ Pulpal sensitivity / severe pain.

 Exposed cementum has an increased mineral
content (Selvig 1966)- Ca, Mg, P, F. & may be
resistant to decay.

 These include bacterial penetration into cementum
as deep as the CDJ.
 In addition, bacterial products such as endotoxins
are also found deep in the cemental wall of the
periodontal pocket.

 Cementum deposition continues after
the teeth have reached into contact with
their functional antagonists and
throughout life.
 No correlation has been established
between occlusal function and
cementum deposition.

 Cementum is repaired by deposition of new
cementum and requires the presence of new viable
connective tissue.
 If epithelium proliferates into that area, repair will
not take place.
 Cementum repair can occur in both vital as well as
non- vital teeth.

 Hypophosphatasia is caused by a mutation in the
tissue specific alkaline phosphatase gene.→
Deficiency in alkaline phosphatase characterized by
premature loss of primary teeth, & reduced
cementum formation.

 It is a developmental anomaly affecting mainly the
skeleton and teeth (affects the skull, clavicle and
dentition).
 A study showed a paucity or complete absence of
cementum due to defective formation of cellular
cementum on both erupted and unerupted
teeth.(Rushton, M.A1956).
 Prolonged retention of deciduous teeth, subsequent
delayed eruption of succedaneous teeth as well as
numerous unerupted supernumerary teeth.

 In this, there is reduced pituitary hormones specially
the growth hormone.
 Individuals with this condition show dwarfism but
have a relatively well proportioned body.
 Decreased cementum formation is associated with
hypopituitarism.

It is a familial, autosomal recessive disease,
characterized by aggressive periodontitis with early
loss of deciduous as well as permanent teeth.

Hyperthyroidism :-
Shedding of deciduous teeth earlier than eruption of
permanent teeth is greatly accelerated.
Hypothyroidism :-
Eruption rate is delayed & deciduous teeth are retained
beyond their normal shedding time.
Down’s syndrome- generalised cementopathia.

 Benign cementoblastoma is a true neoplasm of
functional cementoblasts that form large masses of
cementum like material on the root surface.
 The lesion normally occurs under the age of 25 yrs,
with no sex prediliction.
 Mandible 3 fold more commonly affected than
maxilla.

 Usually slow growing & asymptomatic.
 Radiographically, appears as a dense radio – opaque
mass often surrounded by a thin radiolucent line.
 Treatment - Extraction of the tooth along with
complete removal of growth, failing which, there’s
a recurrence.

HYPERCEMENTOSIS:-
 Refers to prominent thickening of cementum.
 May be localized to one tooth or effect the entire
dentition.

 Occurs as a generalized thickening of cementum
with nodular enlargement of apical third of root / as
spike like excrescences created by either the
coalescence of cementicles that adhere to root / the
calcification of periodontal fibers at the site of
insertion into the cementum. ( Lester, 1969).
 If the over growth improves the functional qualities
of the cementum; it is termed as ‘cemental
hypertrophy’.

 If the overgrowth occurs in non - functional teeth / if
it is not correlated with increased function, it is
termed ‘Hyperplasia’.
 In localized hypertrophy, a spur or prong like
extension of cementum may be formed- found in
teeth that are exposed to great stress.

 Sometimes, embedded calcified round bodies are
found in localized areas of hyperplastic
cementum.& are designated excementosis, &
develop around degenerated epithelial rests.
 Etiology is varied & includes excessive tension from
orthodontic forces,excessive occlusal forces & in
teeth without functional antagonists, as an attempt to
keep pace with excessive tooth eruption.

 In low – grade periapical irritation from pulp
disease it compensates for the destroyed fibrous
attachment to tooth.
 Paget’s disease, Osteitis deformans
Hyperpituitarism. Gigantism & Acromegaly. –(
Sponge, 1979).

 Calcified bodies in the PDL. that are adherent to or
detached from the root surface & its diameter rarely
exceeds 0.2 mm.
 Develop from calcified epithelial rests, around small
spicules of cementum / alveolar bone traumatically
displaced into PDL., from calcified Sharpey’s fibers
and thrombosed vessels within the PDL.

 These are masses of cementum generally situated
apical to teeth to which they may or may not be
attached.
 They are considered either odontogenic neoplasms /
developmental malformations.
 Occurs more frequently in females than males.

 Seen more commonly in mandible as compared to
maxilla and
 May be single / multiple.
 Radiographically, the lesion appears as a discrete,
dense, radio-opaque mass in which isolated
radiolucent markings may be seen.

 Detachment of fragments of cementum from the
root surface is known as ‘Cemental tear’, which
may be complete or incomplete.
 Detached cementum may be reunited by new
cementum formation or may be completely resorbed
/ undergo partial resorption followed by the addition
of new cementum & embedding of collagen fibers.

 Mechanical and chemical means have been used to
promote favorable root surface characteristics.
 Regeneration, repair and new attachment are the
aspects of periodontal healing that have a special
bearing on the results obtainable by treatment.

 It is well accepted that in order to improve
periodontal healing, root planing / root conditioning
is a necessary antecedent to mesenchymal cell
migration & attachment onto the exposed root
surface.
 Root conditioning can be done by using acids (citric
acid, HCL, Lactic acid & EDTA), Fibronectin &
EMP.

 The teeth treated with acid demineralization heal by
connective tissue reattachment, with evidence of
accelerated cementogenesis.
 It removes the dentinal smear layer, enlarges the
opening of dentinal tubules & exposes the collagen
dentinal matrix, which provides a substrate for
fibrin linkage & can support attachment &
migration.

 Attachment mechanism of cementum to dentin is both of
biological interest & of clinical relevance, since
pathological alteration & clinical intervention may
influence the nature of exposed root surface.
 Hence, the quality of the new attachment that forms
depends on the repair cementum that is deposited.
 The mechanism of binding together of these hard tissues is
essentially same for AEFC & CIFC.

Repaired cementum adheres very well to the root surface if a resorptive phase
precedes new matrix deposition, implying that odontoblasts favorably
precondition the root surface.(Bosshardt DD 2005
From a biochemical perspective, this arrangement appears optimal
for a strong union between dentin & cementum
Resulting in an amalgamated mass of minerals
Then it spreads through the surface layer of dentin, across the
dentin – cementum junction & into cementum
Mineralization of mantle dentin starts internally & does not reach the surface
until collagen fibrils of dentin & cementum blend together

Molecule: Biological Activity:
IGF-1. Proliferation, differentiation, matrix synthesis
FGF. Proliferation, differentiation, matrix synthesis,
angiogenesis.
PDGF. Proliferation, differentiation, matrix synthesis.
TGF-ß. Matrix synthesis, angiogenesis, chemotaxis.
BMPs. Matrix synthesis, differentiation, bone formation.
EGF. Proliferation, differentiation
CGF. Proliferation, differentiation.

MOLECULES….. BIOLOGICAL ACTIVITY….
Matrix components:
- Collagens.
- BSP.
- OPN.
- Fibronectin.
- Osteonectin.
Cementum attachment
protein:
- Cementum – derived
growth factor,
isoform of IGF-1.
 Cell adhesion, differentiation;
regulates proliferation
 Cell adhesion, differentiation,
mineralization
 Cell adhesion; regulates
differentiation and survival
 Cell adhesion, differentiation,
regulates proliferation
 Regulates angiogenesis,
differentiation, and proliferation
 Cell adhesion, differentiation.
 Mineralized tissue-forming
cells respond better than
fibroblasts to these proteins.

CARIES OF CEMENTUM
• Caries of cementum also called as SENILE
CARIOUS LESION
• They are located almost excusively on the
root surfaces of the teeth, but sometime they are
associated with partial denture clasp due to
advanced gingival recession.

•Teeth with Hypercementosis are of practical
significance because the extracion of such teeth may
necesite the removal of bone
•These can anchor the tooth so tightly to the socket
the jaw or parts of it may be fractured in an attempt
to extract the tooth
•These possibilty indicates the necessity for taking
xray before extraction

TOOTH RESORPTION –
According to the Glossary –
Contemporary Terminology for Endodontics (1998),
“Resorption is defined as a condition associated
with either a physiologic or a pathologic process
resulting in the loss of dentine, cementum and/or
bone

RESORPTION CLASSIFICATION
1.INTERNAL RESORPTION,
2.EXTERNAL RESORPTION,
3. COMBINED INTERNAL AND
EXTERNAL RESORPTION,
4.TRANSIENT APICAL BREAKDOWN

External Resorption
Replantation of tooth
Orthodontic forces
Eruption of neighbouring teeth
Root fracture
Trauma
Necrotic pulp
Root Planing
Pathology like cysts, Ameloblastoma, Giant cell tumour,
Fibrous osseous lesions
Hereditarywww.indiandentalacademy.com

AETIOLOGY FOR CERVICAL EXTERNAL
RESORPTION
Bleaching
Trauma
Root planning
Hereditary
Orthognathic surgery

EXTERNAL SURFACE RESORPTION
• It is a transient phenomenon in which the tooth undergoes spontaneous
destruction and repair.
• It is found in all the teeth and considered to be a normal physiological
response.
• It is a self-limiting process and does not require any treatment.
EXTERNAL INFLAMMATORY ROOT RESORPTION
It is described as a bowl shaped defect which penetrates the dentine
This occurs following irritation or injury of the periodontium due to trauma,
periodontal infection or orthodontic treatment
EXTERNAL REPLACEMENT RESORPTION:
The primary cause is due to laxative injury.
This is continuous process by which the teeth is gradually resorbed and
replaced by bone.
It differs from Ankylosis because of the presence of intervening inflamed
connective tissue.

CURRENT CONCEPT

Activation of the Canonical Wnt Signaling Pathway
Induces Cementum Regeneration.
Canonical Wnt signaling was induced by (i) local
injection of lithium chloride; (ii) local injection of
sclerostin antibody; and (iii) local injection of a
lentiviral construct overexpressing β-catenin. The
results showed that the local activation of canonical
Wnt signaling resulted in significant new cellular
cementum deposition and the formation of well-
organized periodontal ligament fibers,
JBone Miner Res. 2015 Jan 1

Pulp and periodontal tissue repair - regeneration or
tissue metaplasia after dental trauma.
The healing responses in the pulp and periodontium
after trauma strongly indicates that the survival of the
cell layer next to cementum appears to be crucial for
PDL healing including alveolar bone. The survival of
HERS appears to be decisive for further root
development. Finally, the presence of ischemic but
intact pulp tissue appears to be strongly related to
survival or regeneration of tertiary dentin.
Dental Traumatology 2011;

Hypercementosis: a challenge for
endodontic therapy
The clinical implications of teeth with hypercementosis,
in cases of biopulpectomy and necropulpectomy, lead to
pay attention to its different type and severity. Therefore,
the clinician should evaluate the necessity of adapting
the usual endodontic therapy approach to assure all
Endodontics principles and reach treatment success.
RSBO. 2011 Jul-Sep;8(3):321-8

(1) The explant culture of DP led to harvesting of a
relatively pure cell population of DTSCs;
(2) DTSCs express pluripotent stem cell markers
(3) DTSCs are multipotent cells with high differentiation
potential that are able to contribute to all embryonic
germ lineage formation.
(4) DTSCs are almost unlimited source of young stem
cells with easy access.
Stem Cells in Dental Pulp of
Deciduous Teeth
TISSUE ENGINEERING: Part B
Volume 18, Number 2, 2012

 Cementum is a part of periodontal attachment
apparatus, & by virtue of its structural dynamic
qualities, provides tooth attachment and
maintains occlusal relationship.
 These multiple functions are fulfilled by the
biological activity and reactivity of cementoblasts,
which deposit two collagen containing varieties of
cementum with completely different properties.

 Unless disturbed, cementum covering of the root ↑
in thickness throughout life, faster apically than
cervically.
 Chemical composition is almost similar to bone.
 The dynamic features of cementum are particularly
highlighted by its repair potential.

 Minor, non - pathological resorption defects on the
root surface are generally reversible and heal by
reparative cementum formation.
 In diseased periodontium, cementum may undergo
alterations in structure as well as in the composition
of its organic and inorganic components
consequential to pathological changes.

The discovery of a variety of non – collagenous
proteins in cementum has opened new vistas for
research - the application of cementum derived
growth factor / attachment factors may result in
accelerated wound healing & in controlled neo –
cemento genesis following periodontal
regeneration therapy.

CONCLUSION
• -Cementum is best considered in functional terms as two
tissues, with one providing attachment and the other
adaptation to tooth wear and movement.
• -Cementum is thinnest at the cementoenamel junction and
the relative softness of the cementum makes it susceptible to
abrasion thereby exposing the underlying sensitive dentin.
• -Therefore whenever the cemental surface is exposed to the
oral environment such as by gingival recession, proper
treatment procedures has to be followed to prevent the
increased sensitivity experienced by the patient.

BIBLIOGRAPHY
• 1. Oral Histology – Ten Cates, 5th
and 6th edition
• 2. Orban’s Oral Histology and
Embryology – S.N. Bhaskar, Eleventh
Edition.
• 3. Pathways of the Pulp – 8th Edition
– Stephen Cohen, Richard C. Burns.
• 4. Textbook of Oral Pathology –
William G. Shafer.
• 5. Endodontic Practice – Louis I.
Grossman, Eleventh Edition.•

A creative man is motivated by the desire
to achieve, not by the desire to beat others.
Ayn Rand

Cementum / rotary endodontics courses

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Andere mochten auch

Andere mochten auch (7)

Ähnlich wie Cementum / rotary endodontics courses

Ähnlich wie Cementum / rotary endodontics courses (20)

Mehr von Indian dental academy

Mehr von Indian dental academy (20)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

Cementum / rotary endodontics courses