this ppt includes information regarding a dental tissue know as the cementum. It is a hard tissue covering the roots of the teeth. this ppt includes, the composition, formation, types, cells and functions the cementum plays in maintaining the integrity of the tooth .

2.  Introduction
 Composition
 Properties
 Cementogenesis
 Classification
 Cells of cementum
 Cementum proteins
 Cementoenamel junction
 Functions
 Cementum resorption
 Cementum regeneration
 Age changes
 Clinical significance

3.  Cementum was first demonstrated by FRANKE & RASCHKOV, in 1835.
 Cementum is a calcified, avascular, non-innervated mesenchymal tissue that forms the
outer covering of the anatomic root. ( Cararanza 11th edition )
 The cementum is a specialized mineralized tissue covering the root surfaces and,
occasionally, small portions of the crown of the teeth. ( Lindhe 9th edition )
 Cementum begins at the cervical portion of the tooth and continues to the apex
 It acts as a medium that for the attachment of collagen fibers that bind the tooth to the
surrounding structures.

5.  Thickest – at Apex 150um to 200um , Thinnest - at CEJ 20 to 50 um
 Like dentin, forms throughout the life of the tooth .
 Hardness < dentin
 More permeable than dentin.

8. TIME OF
FORMATION
• Primary
• Secondary
PRESENCE OR
ABSENCE OF
CELLS
• Acellular
• Cellular
TYPE OF FIBERS
• Intrinsic
• Extrinsic

9.  In 1986, scientists Schrorder & Page classified cementum into the
following type based on the location, morphology & histology of
cementum.
1. Acellular Afibrillar Cementum ( AAC)
2. Acellular Extrinsic Fiber Cementum (AEFC)
3. Cellular Intrinsic Fiber Cementum (CIFC)
4. Cellular Mixed Stratified Cementum (CMSC)
5. Intermediate Cementum
(Hyaline Layer of Hopewell Smith )

10. AAC AEFC CMSC CIFC HYALINE LAYER
No cells No cells Cememtocytes
present
Cementocytes
Present
Separates dentin
from cementum
No fibers Fibers seen are
Sharpey’s fibers
Sharpeys fibers
seen from PDL and
fibers from the
cementum itself
Intrinsic fibers
formed by
cementoblasts
Does not resemble
cementum or
dentin
No function in
tooth attachment
Adapts to
functionally
dictated alterations
such as mesial
drift
minor role in
attachment
Represents areas
where cells of
HERS become
entrapped in
rapidly deposited
dentin or
cementum matix
Location - Coronal
cementum
(Cervical Margin)
Location – coronal
half of the root
Location – Apical
3rd and furcation
areas
Location – apical
3rd and inter
radicular
cementum
Location – Apical
2/3rd of roots of
molars

11. I. CEMENTOBLASTS
 They make up the organic matrix of the cementum, called CEMENTOID.
 Cementoblasts move outwards during cementum formation & some of them are entrapped in the
matrix during deposition & are called Cementocytes .
 These cells have numerous mitochondria, a well formed golgi apparatus and large amount of
endoplasmic reticulum.

12. II. CEMENTOCYTES
 Spider like cells, situated in the lacunar spaces in mineralized cementum.
 incorporated into cellular cementum
 A typical cementocyte has numerous cell processes or canaliculi radiating from it’s cell body.
 Most of the processes are directed towards the periodontal surface of cementum, as they
get their nutrition from the PDL.
III. CEMENTCLASTS
often located in howship’s lacunae, are found on surface of cementum.
responsible for extensive root resorption that leads to primary teeth exfoliation and localized
cemental resorptions seen in adult dentin.

13.  I. Glycosaminoglycans
 The percentage of glycosaminoglycans is high in tissues subjected to compressive forces, such
as cementum.
 The major glycosaminoglycans present in human cementum are :- i. hyaluronic acid,
ii. dermatan sulfate
iii. chondroitin
sulfate.

14.  Cementum contains major phosphoproteins such as osteopontin and bone sialoprotein.
 Osteopontin is present within the periodontal ligament in mature teeth.
 In the periodontium, osteopontin is expressed by cells in close contact with acellular cementum as
well as by cementocytes
 Sialoprotein and osteopontin remain bound to collagen matrix and they possess cell-attachment
properties.
 sialoprotein modulates the process of cementogenesis and is involved in the process of
chemoattraction, adhesion and differentiation of precementoblasts.
 Both sialoprotein and osteopontin are believed to play a role in the differentiation of cementoblast
progenitor cells to cementoblasts

15.  Two major Gla-containing proteins associated with calcified hard tissues :- i. osteocalcin
ii. Matrix gamma-carboxyglutamic acid
protein
 osteocalcin expression is localized in cells lining cellular cementum and acellular cementum.
 Osteocalcin play a crucial role in the mineralization process.
 Osteocalcin is secreted by osteoblasts. (Mariotti, 1993).

16.  Miki et al. (137) were the first to report the presence of mitogenic activity in cementum obtained
from human teeth.
 Nakae et al. (144) isolated and characterized mitogenic factors present in the cementum matrix
of bovine teeth.
 . In addition to fibroblast growth factor, which binds strongly to heparin, another mitogenic factor
with moderate heparin affinity was present in cementum but not in alveolar bone. This factor
was named cementum-derived growth factor.
 Cementum-derived growth factor may promote the migration and growth of progenitor cells,
present in the adjacent structures, toward the dentin matrix and participate in their differentiation
into cementoblasts .

17. SHARP / BUTT JOINT GAP JOINT OVERLAP JOINT
Cementum and enamel meet in a
sharp line
Cementum does not meet enamel
& there is a gap between the two.
Cementum overlaps enamel
Delay in degeneration of HERS,
that prevents the contact
between dental sac and dentin
REE covering the crown
degenerates near the cervical
portion, permitting the cells of
the dental sac to come in contact
with enamel & form cementum
over it
Seen in 30% Seen in 10% Most common type, seen in 60%

18.  Primary function of cementum :- medium for the attachment of collagen
fibers that bind the tooth to alveolar bone.
 Since collagen fibers of the periodontal ligament cannot be incorporated into
dentin, a connective tissue attachment to the tooth is impossible without
cementum
 The principal function of cementum is to provide anchorage of the tooth in its
alveolus.
This is accomplished via the collagen fiber bundles of the periodontal
ligament, whose terminations (Sharpey’s fibers) become firmly embedded in
cementum during the process of cementogenesis.

19.  As the most superficial layer of cementum ages, a new layer of cementum must be
deposited to keep the attachment apparatus intact.
 Another function of cementum is to assist in maintaining occlusal relationships.
 As the occlusal and incisal surfaces of teeth are abraded away due to attrition, tooth
eruption occurs to compensate for the lost substance, and deposition of new
cementum occurs at the apical root area. This process also serves to maintain the
width of the periodontal ligament space at the apex of the root.

20.  Resorption or fractures in the root surface are repaired by deposition of
cementum
 Cementum is more resistant to resorption than bone
 In cases of excessive trauma, resorption of cementum takes place.
 In such case cementum is repaired by the deposition of cellular cementum.
 Cementum repair takes place in vital and non – vital teeth.

21.  Cementum is more resistant to resorption than bone, however under certain conditions
, root resorption takes place
 Resorption takes place by multi nucleated odontoclasts.
 Local factors :- TFO , ortho mvt, cysts & tumors, embedded teeth, teeth without
functional antagonist .
 Systemic :- Ca deficiency , hypothyroidism, Paget's disease.
 These resorptions are however minor, and reversible .
 After the resorptive activity of odontoclasts has ceased and the stimulus for new
odontoclasts disappears , they become filled by repair cementum .
 Newly formed cementum is demarcated by a deep staining line called the “reversal
line” which delineates the border of the previous cementum .
 Embedded fibers of the PDL, establish a functional relation with the new cementum .
 Cementum requires the presence of viable C.T , if the epithelium grows in the area of
resorption, repair will not take place .

22.  Slavkin & Boyde (1975) proposed that enamel matrix proteins are involved
in the formation of cementum.
 In developing human teeth amelogenin was found to be present in the
area where cementogenesis is initiated and a cementum-like tissue was
formed when cells of the dental follicle were exposed to enamel matrix.
 The demonstration of amelogenin at the apical forming end is in
agreement with previous studies (Lindskog 1982 , Lindskog &
Hammarstrom 1982)
 The importance of cervical third of cementum is that it contains extrinsic
fiber cementum and its regeneration is considered to be gold standard for
periodontal regeneration.

23.  Smooth surface becomes irregular
 Continuous deposition of cementum occurs with age in the apical area
 Cementum becomes less permeable with age
 Resorption of root occurs with age which is covered by cemental repair.
 Cementum resorption and repair takes place .
(Bosshart & Selvig , 1997)

25.  A cemental tear is the partial or complete detachment of the cementum from the cemento-dentinal junction or
along the incremental line within the body of cementum.
 Internal factors due to the inherent structural weakness of cementum and its interface with the dentine,
and external factors that are associated with stress have been proposed as the two mechanisms responsible for
the development and propagation of cemental tears.

26. TREATMENT :-
 Fragment that is located at the coronal third of the root may be removed via nonsurgical scaling and root planing
(Jeng et al., 2018).
 For those fragments located deeper apically along the root and/or when nonsurgical periodontal treatment has
been ineffective, surgical periodontal approach is recommended (Jeng et al., 2018)
 Apical surgery is often indicated if the fragment is located at the apical third of the root with signs of apical
pathosis, in which case the need for prior root canal re/treatment must be considered (Jeng et al., 2018).
 Traumatic occlusion is a factor that may also affect success. Hence, its management, such as occlusal
adjustment and splinting, is also crucial in preventing recurrence
(Kang et al., 2016; Tai et al., 2007).
 Guided tissue regeneration (GTR), with or without bone replacement grafting, has also been advocated to
enhance the reattachment of the periodontal apparatus along the affected root surface and to promote osseous
tissue ingrowth of the bony defect
(Blum et al., 2013; Camargo et al., 2003; Damasceno et al., 2012; Dietrich et al., 2003; Kasaj et al., 2009; Lin et
al., 2010; Lin et al., 2014; Marquam, 2003; Tulkki et al., 2006).

27.  Cementicles are spherical calcified bodies lying free in the periodontal membrane.
 Located :- attached to cementum ( sessile or attached cemticles )
Lying freely within the PDL space ( free cementicles)
(Embedded cementicle)
 Origin :- calcified epithelial rests,
from dystrophically calcified connective tissue within the areas of indefinite fibers,
from small spicules of cementum or alveolar bone traumatically displaced into the
periodontal membrane and modeled by the functional movement of the tooth,
from calcified Sharpey's bundles.
Calcification of thrombosed (blocked) capillaries in the periodontal ligament
(Oral Surgery, Oral Medicine, Oral Pathology, Volume 2, Issue 8)

28.  ‘an excessive growth of cementum of the tooth’, observed radiographically as circumscribed
cementum hyperplasia (Gardner and Goldstein in 1931)
 may involve a single tooth, several teeth or the entire dentition
 Most commonly - affects the premolar teeth and presents in bilaterally symmetric distribution.
 Radiographically - overgrowth of cementum contiguous with normal radicular cementum and
contained within the boundaries of the periodontal ligament and lamina dura
 Cause - secondary to either local factors or systemic disorders,
most commonly :- idiopathic, age-related phenomenon
Systemic disturbances:- Paget’s disease of bone,
thyroid goiter,
rheumatic fever,
arthritis, acromegaly,
calcinosis
vitamin A deficiency.

29.  local origin usually involve one tooth or a small group of teeth :- periapical pathosis,
parafunctional occlusal
trauma,
lack of functional opposition
Diagnosis – Radiographic
Cemental hypertrophy :- If the overgrowth improves the functional qualities of cementum
Cemental hyperplasia :- Seen in non-functional teeth or if it is not correlated to increased function.

30.  Cementoblastoma is a rare benign odontogenic tumor that accounts for less than 1%
of all odontogenic tumors.
 Cementoblastoma commonly presents with pain and associated swelling due to bony
expansion of the buccal and lingual aspects of the alveolar ridges.
 Radiographically - well-circumscribed, radiopaque mass attached to the root of the
involved tooth with a surrounding thin radiolucent zone.
 Treatment :- complete excision of the mass with removal of the affected tooth
Aaron R. Huber Æ Gretchen S. Folk
RADIOLOGY-PATHOLOGY, 30 Dec 2008

31. HYPOPHOSPHATASIA
 Hypophosphatasia is a rare inherited disorder characterized by defective bone and tooth
mineralization, and deficiency of serum and bone alkaline phosphatase activity.
 Characterized by loosening and premature exfoliation of deciduous teeth, mainly anterior
teeth .
 Radiographically, the teeth appear hypocalcified and have large pulp chambers
 Exfoliated teeth microscopically, showed complete absence or isolated areas of abnormal
cementum.

32.  In 1923, Gottlieb reported a patient with fatal case of influenza and
disease called “ diffuse atrophy of bone”
 Characterized by loss of collagen fibers in pdl and their replacement by
loose connective tissue and extensive bone replacement resulting in
widened PDL space.
 Gottlieb attributed this condition to inhibition of continuous cementum
formation which he considered essential for maintenance of PDL fibers
 He termed this as “ cementopatha”

33.  Calculus embedded deeply in cementum may appear morphologically similar to
cementum ( Newman et al )

34.  Fusion of two teeth after root formation has been completed .
 Teeth are united by cementum only.
 Cause – Traumatic injury or overcrowding , such that the interdental bone is
resorbed , and the two roots in approximate contact are fused by the deposition of
cementum between them .

35.  Etienne Mornet, Hypophosphatasia, Best Practice & Research Clinical
Rheumatology,Volume 22, Issue 1,2008.
 Bruckner, R. J., Rickles, N. H., & Porter, D. R. (1962). Hypophosphatasia with
premature shedding of teeth and aplasia of cementum. Oral Surgery, Oral
Medicine, Oral Pathology, 15(11), 1351-1369. https://doi.org/10.1016/0030-
4220(62)90356-0
 Carranza clinical periodontology 10th edition
 Orbans oral histology and embryology 12th edition
 Cementum – a dynamic tissue covering the root. Periodontoloy 2000 vol 13 Dieter
D Bosshardt & Knut A Selvig .
 Tissues and cells of the periodontium. Perio 2000 vol 3 1993. Thomas M. Hassell