The periodontium consists of the gingiva, periodontal ligament, root cementum, and alveolar bone. The gingiva is pink, firm, and resilient with a stippled surface. It consists of masticatory mucosa and protects the underlying periodontal tissues. The periodontal ligament is a soft, vascular connective tissue that surrounds tooth roots and connects the cementum to alveolar bone. It provides support, absorbs shock, senses function, and facilitates nutrient exchange between the tooth and bone.

2. Dr. Enas Elgendy
Ass. Professor of Oral Medicine,
Periodontology& Oral Diagnosis
Faculty of Dentistry
Kafrelsheikh University

3. The term Periodontium arises from the Greek
word peri meaning around and odont meaning tooth,
thus it can be simply defined as the “tissues investing
and supporting the teeth”.
The various diseases of the periodontium are
collectively termed as Periodontal diseases.
Their treatment is referred to as Periodontal
therapy.
The clinical science that deals with the periodontium
in health and disease is called Periodontology.
The branch of dentistry concerned with prevention
and treatment of periodontal disease is termed
Periodontics or Periodontia.

6. The tissues that surround
and support the teeth are
known as the
periodontium.
It includes:
1- The gingiva.
2- The periodontal ligament.
3- The root cementum.
4- The alveolar bone.

7. The gingiva is that part of the
oral mucosa which surrounds the
tooth and covers the alveolar
ridge.
It forms a connection with the
tooth and protects the underlying
tissues of the periodontium (bone
& periodontal ligament) from the
oral environment. AM, alveolar mucosa
G, gingiva
MGJ, mucogingival junction

8. Pink in color
 Firm and resilient (resist deformity) in consistency and not bleeding
on probing
 Knife-edged and scalloped to conform to the contour of the teeth.
The surface of the gingiva exhibits an orange peel-like appearance
referred to as stippling

9.  The periodontium is consists of ………………,
…………….., ……………., …………….
 Healthy Gingiva is ………………, ……………..,
…………………, ……………..

10. 1. Masticatory mucosa:
Is a tissue that is firmly attached to the underlying bone
and covered with parakeratinized or keratinized
epithelium. The gingiva and the tissue covering the hard
palate are examples.
2. Lining mucosa:
Loosely attached to their underlying structures and
covered with non-keratinized epithelium. Lips, cheeks,
floor of the mouth.
3. Specialized mucosa:
Covers the dorsal surface of the tongue.

11.  The gingiva consists of which type of mucosa?
1. Alveolar mucosa
2. Masticatory mucosa
3. Specialized mucosa
4. Non of the above

12. The marginal (free)
gingiva
The interdental
gingiva
The attached
gingiva

13.  The marginal gingiva forms a cuff 1-2 mm wide around the neck of the tooth and it is the
external wall of the gingival crevice.
 The marginal gingiva can be separated from the tooth by a blunt probe.
 The surface of marginal gingiva is smooth in contrast to the attached gingiva which is
stippled.
 The marginal gingiva is demarcated from the attached gingiva by a shallow, v-shaped or
an indentation called the free gingival groove.

14.  It is defined as the space or shallow crevice between the
tooth and the free gingiva.
 It is V-shaped and barely permits the entrance of a
periodontal probe.
 Under normal or ideal conditions it is about 2 to 3 mm.
 The gingival sulcus is probing depth of a clinically-normal
gingival. It provides good resistance to mechanical forces.

15. It is an inflammatory exudate
that carries polymorphonuclear
leukocytes and other antimicrobial
substances into the gingival
crevice (sulcus).
If filter paper strip is inserted
into the gingival crevice it will
absorb gingival fluid already in the
crevice and also stimulate the
outward flow of the gingival fluid.
The increase in gingival fluid
flow is also associated with
inflammation.

16. The gingival fluid forms part of the defense mechanism of the
dentogingival junction.
In summary, it performs the following functions:
It washes the crevice, carrying out shed epithelial cells,
leukocytes and bacteria.
It contains antimicrobial components e.g. lysosome, antibodies
and complement.
It carries PMNLs and macrophages which are capable of
phagocytosing bacteria.

17. Facial papilla Lingual papilla Col region
The interdental gingiva occupies the space in the
interdental embrasure apical to the contact point. There
are three parts of interdental gingiva:

18.  In anterior teeth, the interdental papilla is pyramidal form while
in the molar region, the papillae are flattened in buccolingual
direction (tent shape).
The shape of the interdental papilla is determined by:
1. the contact relationships between the teeth
2. the width of the proximal tooth surfaces
3. coarse of the CEJ.

19. If the contours of
interproximal contact are
flat, the gingiva will be
narrow and short.
If the proximal contours
are more convex with a
small coronally positioned
contact area, the interdental
gingiva will be broad and
high.

20. The loss of papilla can lead to
cosmetic deformities (so-
called “black triangle”),
phonetic problems (space
allows passage for the air or
saliva), and lateral food
impaction.

21. In teeth with contact surface
rather than contact point, the
interdental papilla has a col
region. The "col" is depression
which joins the facial and lingual
papilla.
 The col region is covered by a
thin non-keratinized
epitheliumwhich is not a
powerful barrier against bacterial
insult.
.

22. The interdental region is of special
importance
(give reasons)
The col region is covered by a thin non-keratinized
epitheliumwhich is not a powerful barrier against
bacterial insult, as it is the site of the most
persistent bacterial stagnation. It is the site of initial
lesion in gingivitis .

23. The shape of the interdental papilla is determined by:
1. the contact relationships between the teeth
2. the width of the proximal tooth surfaces
3. coarse of the CEJ.
4. All of the above

24. It extends from the free gingival groove
to the mucogingival junction where it
meets the alveolar mucosa.
The attached gingiva is tightly bound to
the underlying alveolar bone.
 Function of attached gingiva:
1- It provides gingival tissue that can
withstand the mechanical forces of
mastication, brushing and tension applied
on mucosa.
2- Prevent free gingiva from being pulled
away from the tooth when tension is
applied to the alveolar mucosa.

25. The surface of the attached gingiva is stippled like orange peel.
The width of the attached gingiva can vary from zero to 9 mm. Attached
gingiva is greatest in incisor region (3.5-4.5 in maxilla, 3.3-3.9 in
mandible). Least in canine and premolar area (1.9 mm in maxilla, 1.8

26. The alveolar mucosa is
separated from the
periostium by a loose,
highly vascular
connective tissue. Thus
the alveolar mucosa is
relatively loose and
mobile tissue, deep red,
in marked contrast to
the pale pink attached
gingiva.

27. (1) mucogingival junction,
(2) interdental papilla,
(3) free gingiva groove,
(4) attached gingiva,
(5) alveolar mucosa,
(6) gingival margin
(1) Enamel, (2) gingival margin, (3)
small gingival sulcus, (4) free gingival
groove, (5) alveolar bone, (6) cemento-
enamel junction, (7) cementum,
(8) periodontal ligament

28.  The salivary flow, saliva contains lysozyme and
IgA.
 Cell turnover and surface shedding
(desquamation).
 Anatomical epithelial seal.
 The gingival fluid, it contains several defensive
components.

30. Complete:
 The marginal gingiva is demarcated from the
attached gingiva by …………………..,
 and the attached gingiva is demarcated from
the alveolar mucosa by ………………
 The Gingival Defense Mechanisms Include
………………….., …………………, …………………,
………………….

31. A
B
C
D
What are the name of A , B , C and D?

32.  The understanding of
clinical features of
periodontium is enhanced
by a knowledge of
histological component of
tissue.

33. Gingival
epithelium
Gingival connective
tissue
The gingiva is consists of
Oral (outer)
epithelium
Sulcular epithelium
Junctional
epithelium

34. Three zones of gingival
epithelium:
Oral (outer) epithelium which is keratinized
(from the mucogingival junction to the
gingival margin).
Sulcular epithelium which are non-
keratinized (lines the gingival crevice).
Junctional epithelium which are non-
keratinized (lies at the base of the gingival
crevice).

35. Keratinized or parakeratinized
consist of four layers:
1) Basal or formative cells layers of columnar
cells (The deepest cells); it is characterized
by active mitosis (stratum basal or stratum
grrminativum).
2) Prickle or spinous cell layer of polygonal
cells (stratum spinosum).
3) Granular cell layer in which the cells are
flatter and contain many particles of
keratohyaline (stratum granulosum).
4) Cornified or keratinous cell layer in which
cells have become flat, shrunken and
keratinized (stratum corneum).

36.  Gingival epithelial cells are
connected to each other by
desmosomes.
 Desmosome consists of two
attachment plaque associated with
tonofilaments and an intercellular
cementing substance formed of
polysaccharides.
 Gingival epithelial cells are also
attached to the underlying
connective tissue by
hemidesmosome (one
attachment plaque).

37. Gingival epithelial cells are connected to each other by
desmosomes.
Gingival epithelial cells are also attached to the underlying
connective tissue by hemidesmosome

38. The boundary between
the oral epithelium and
the underlying connective
tissue has a wavy course.
The connective tissue
portion which project into
the epithelium is called
connective tissue
papillae and are
separated from each
other by epithelial
ridges (rete pegs). Epithelium/connective tissue interface
A, connective tissue. Arrows point at finger-like
papillae in papillary layer.
B, epithelium. Arrows point at interconnected rete
ridges on the epithelium undersurface.

40. Three zones of gingival epithelium are
……………, ……………… , ……………………….
 Gingival epithelial cells are connected to each
other by …………………, and to the underlying
connective tissue by ……………………

41. It lines the gingival
sulcus facing the tooth
similar to oral epithelium
except the 2nd
layer (it
lacks granular cell layer)
It acts as
semipermeable
membrane allows
bacteria to pass into
gingiva.
Sulcular epithelium
GS, gingival sulcus ICS, intercellular
spaces PKC, parakeratinized epithelium

42. lies at the base of the crevice, it
mediate the connection of the
gingiva with the tooth. In health
the junctional epithelium lies
against enamel and extends to
the cemento-enamel junction
without wavy course at the
junction between the epithelium
and connective tissue.

43. The gingival connective tissue is composed of:
1. Ground substance
2. Gingival fibers
3. Cells
4. Blood vessels
5. Nerves and
6. Lymphatic vessels

44. Connective tissue cells and fibers, together with vessels and
nerves are embedded in a matrix which is synthesized by
fibroblast and it is made up of:
 Glycoproteins: it is a protein-polysaccharide molecule in which
protein component is predominating. Glycoprotein mediates
attachment and migration of fibroblasts.
 Proteoglycans: it is a protein polysaccharide molecule in which
polysaccharide component is predominating.
glucosaminoglycans are polysaccharides which can bind large
amounts of water providing the characteristic resiliency of the
gingiva (i.e. resist compressive force). Glucosaminoglycans also
facilitate transport of: nutrients, metablic products, cells and
cytokines which are chemical massengers that modulate cellular
function.

45. Complete:
 Function of Glycoprotein mediates is
……………………………
 Function of glucosaminoglycan are
…………………………….,
…………………………………..

46. The gingival connective tissue fibers are
produced by the fibroblasts and can be divided
into:
1. Collagen fibers
2. Reticulin fibers
3. Elastic fibers.

47. The arrangement of these fibers
exists into five groups:
1- Dentogingival fibers that are
attached to cementum and fan
out into the gingiva.
2- Alveolo-gingival fibers that
arise from the alveolar crest and
run coronally into the gingiva.
3- Circular fibers which encircle
the tooth.
4- Trans-septal fibers which run
from tooth to tooth coronal to the
interdental septum of bone.
5- Periosteogingival fibers that
attach gingiva to bone.

48.  Reticulin fibers are numerous in the tissue
adjacent to the basement membrane and
surrounding the blood vessels.
 Elastic fibers are only present in association
with blood vessels.

49. The gingival connective tissue fibers are …………,
…………………………,…………………..
The collagen fiber of the gingiva is arranged into
……………………,………………..,
……………………………, ………………………., ……..

50. The different types of cell present in the
connective tissue are:
1. Fibroblasts
2. Mast cells
3. Macrophages
4. Neutrophils
5. Lymphocytes
6. Plasma cells.

51. The gingiva has a rich blood supply
derived from three sources:
1. periodontal ligament
vessels
2. alveolar vessels
3. supraperiosteal vessels,
These links in the gingiva to form
capillary loops in the
connective tissue papilla
between epithelial pegs.
Gingival blood supply
A, vascular plexus adjacent to junctional
epithelium
B, vascular plexus adjacent to oral epithelium
1, blood supply from periodontal ligament
2, blood supply from alveolar process
3, supraperiosteal blood supply

52. Lymphatic drainage starts in connective tissue
papillae and drains into regional lymphnodes;
 from mandibular gingiva into the
submandibular and submental lymphonodes
 from the maxillary gingiva into the deep
cervical lymphnodes.

53. The nerve supply is derived from branches of:
 The trigeminal nerve.
 A number of nerve endings have been
identified in the gingival connective tissue as
tactile corpuscles and temperature and pain
receptors.

54. The gingiva blood supply derived from three
sources ……….., ………….., …………….
The gingiva lymph supply derived
from……………….,…………………………
The gingiva nerve supply derived from…………..,
…………………………………
 The function of gingival fluid are …………,
…………, ……….. , …………….

55. The periodontal
ligament is soft, richly
vascular and cellular
connective tissue which
surrounds the roots of
the teeth and joins the
root cementum with the
lamina dura or the
alveolar bone proper.

56. The Lamina dura is the wall
of the tooth socket that
surrounds the root of a
tooth. The lamina dura is
made up of dense cortical
bone.

58. 1. Supportive function
2. Shock absorbing
function
3. Formative function
4. Sensory function
5. Nutritive function

59. The ligament
consists of:
Collagen Fiber Bundles
Ground Substance
Matrix
Cells
Vessels
Nerves
A, arteriole; BB, bundle bone; C, cementum; CC,
cementocytes; D, dentin; F, fibroblasts; M, cell rests of
Malassez; NV, neurovascular channel; OB,
osteoblasts; OC, osteocytes; SF, Sharpeys fibers; V,
thin-walled venules.

60. Sharpey’s fibers:
The fiber bundles are inserted at
one end into cementum and at
the other end into the socket
(connect between cementum and
principle fibers of periodontal
ligament & between bone and
principle fibers of periodontal
ligament).
Principal periodontal ligament fibers and their
insertion: (1) dentin; (2) cementum with
Sharpey’s fibers, surface covered by
cementoblasts; (3) periodontal ligament space
with principal collagen fibers and scattered
fibroblasts; (4) alveolar bone with Sharpey’s
fibers, surface covered by osteoblasts.

61. AB, alveolar bone; C, cementum; D, dentin; M, cell
rest of malassez; NV, neurovascular channel; OB,
osteoblasts; PDL, periodontal ligament; RL, reversal
line; SF, sharpey's fibers.
Junction of periodontal ligament and alveolar
bone.
Oc, osteocytes
SF, sharpey's fibers

62. The fiber bundles
are classified into:
1)Alveolar crest fibers
2)Oblique fibers:
3)Transseptal fibers
4)Horizontal fibers
5)Interradicular fibers:
6)Apical fibers;
Principal periodontal ligament fiber
groups: (1) alveolar crest fibers; (2)
oblique fibers; (3) transseptal fibers; (4)
horizontal fibers; (5) interradicular
fibers; (6) apical fibers.

63. Cells:
 Fibroblasts
 Cementoblasts
 osteoblasts
 Osteoclasts
 Epithelial rest of malassez
 Formative (stem) cells: which are undifferentiated
mesencymal cells (stem cell) that differentiate to
osteoblast, fibroblast and cementoblast.

64. Fibroblasts are the most
abundant cell type in the
periodontal ligament because of
the high turnover of collagen and
proteoglycan with periodontal
ligament. These cells are actually
engaged in protein synthesis
(collagenase), they are also
responsible for collagen
degradation within the ligament.
CF, collagen fiber
FB, fibroblasts
ICC, intracellular collagen in digestive
vacuoles

65. Cementoblasts on
cementum surface and
osteoblasts on endosteal
and periosteal surfaces of
alveolar bone are
abundant when active
deposition of bone and
cementum is taking place.

66. Osteoclasts
which are derived
from blood
monocytes appear
on bone surface
during bone
resorption.

67. The periodontal ligament ground substance
consists of glycoproteins, proteoglycans and
glucosaminoglycans (GAGs). GAGs is similar in
composition to that of gingival ground substance.
They are important in binding water and may thus
act as cushion in periodontal ligament to resist
forces of mastication.

68. The ligament has a rich
network of blood vessels
from:
1- apical arteries
2- vessels penetrating the
alveolar bone.
Nerve bundles from the
trigeminal nerve follow the
blood vessels from the apex
and through the alveolar
bone to supply the ligament
with tactile, pressure and
pain receptors.

69.  The thickness of the ligament varies from
about 0.3 to 0.1 mm. It is widest at the coronal
part of the socket and narrowest at the apex.
 When functional stresses are heavy the
ligament is thicker and when a tooth is
functionless the ligament can become thinner.

70. Cementum is the
calcified connective
tissue which covers the
root dentin and into
which periodontal
ligament fiber bundles
are inserted. It is
avascular and without
innervations.

71. The thickness of cementum
varies, the coronal third may
be only 16-60 microns and
this very thin layer of cervical
cementum can be easily
removed by dental
instrumentation leaving very
sensitive area exposed. The
apical third can be 200
microns or even thicker. It can
triple its thickness throughout
life.

72. Two different types of cementum:
1)Primary cementum or
acellular cementum
2)Secondary cementum or
cellular cementum
The initial layer of cementum is
acellular but during rapid
cementogenesis, cementoblasts
become entrapped in the newly
formed cementum and are called
cementocytes.

73. Three types of relationships
involving the cementum
may exist at the
cementoenamel junction:
1- Cementum overlaps the
enamel (60% to 65%).
2- Edge-to-edge butt joint
(30%).
3- The cementum and
enamel fail to meet (5% to
10%).

74. There are two sources of collagen
fibers in cementum:
1- The extrinsic fibers (Sharpey’s fibers)
which are the embedded portion of
the principal fibers of the periodontal
ligament, arranged at right angle to
the root surface and are synthesized
by fibroblasts of the periodontal
ligament.
2- The intrinsic fibers which belong to
the matrix of cementum forming
irregular mesh work and they are
synthesized by cementoblasts.

75. Unlike bone there is no evidence of cementum remodelling.
Cementum resorption may occur as a consequence of faulty
orthodontic movement or pressure from tumor. The greatest
thickness of cementum is formed at the apex and in the
furcation area.
Both cortical and cancellous alveolar bone are constantly
undergoing remodelling (resorption followed by formation) in
response to tooth drifting and changes in functional forces acting
on the teeth to compensate for ever-changing positions of teeth.

76. The alveolar process is that part
of the jaw bone which supports the
teeth. It is partly tooth dependent
and after tooth extraction some bone
resorption follows.
Alveolar bone:
1-Alveolar bone proper
(lamina dura in radiographs)
2-Trabecular bone
3-Compact bone

77. Supporting alveolar bone: cancellous
and cortical bone that surrounds the
alveolar bone proper.

78. Alveoli: The space in the alveolar bone that
accommodate the roots of the teeth (tooth
socket).
The alveolar bone proper is the
compact bone, which in radiographs appears as
a continuous radioopaque line (white line)
around the roots of the teeth is called "lamina
dura". It lines the tooth socket and is
perforated by numerous Volkmann's canals
through which blood vessels, lymphatics, and
nerve fibers pass from the alveolar bone to the
periodontal ligament.
Crestal lamina dura (the
alveolar crest) covers the crest of
interproximal bone and called which generally
parallels the cemento-enamel junction at a
distance of 1-2 mm apical to it.

79. Interproximal bone (interdental septum): bone located
between the roots of adjacent teeth.
Interradicular bone: bone located between the roots of
multirooted teeth.
Radicular bone: alveolar process located on the facial or
lingual surfaces of the roots of teeth

80. The basic structural units of the cortical bone are the osteons or the
Haversian system with longitudinally oriented cylindrical structures built
around vascular central canals called Haversian canals. The nutrition of
the bone is secured by the blood vessels in the Haversian canals, which
are connected with each other by anastomoses running in Volkmann's
canals.
ECL, external
circumferential
lamellae
HC, Haversian canals
HS1, young Haversian
system
HS2, mature
Haversian system
IB, interstitial bone
P, periosteum
VC, Volkman canal

81. Three types of cells are found associated with bone:
1- osteoblasts,
2- osteocytes
3- osteoclasts
These cells can be transformed from one type to another or whether they are of
separate origins. Actively resorbing osteoclasts adhere to the bone surface and
produce lacunar pits called Howship's lacunae.

82. Fenestration is window-
like defect in the bone.
Dehiscence denuded
areas extend through the
marginal bone.

84. What are the name of A and B?
A B