The document discusses the dento-gingival unit, emphasizing the junctional epithelium's structure, functions, and its dynamic role in periodontal health. It covers various aspects including the development, cellular composition, and the attachment mechanisms of the junctional epithelium, as well as its interaction with the gingival fibers and the immune response. Additionally, it highlights the importance of the junctional epithelium in maintaining periodontal health and preventing disease progression.

1. DENTO-GINGIVAL UNIT
Sangeeta Roy
Pg 1st year

2.  Introduction
 Definition
 Junctional epithelium
◦ Definition
◦ Development of junctional epithelium
◦ Structure
◦ Epithelial attachment
◦ Dynamic aspects of junctional epithelium
◦ Expression of various molecules and their functions
◦ Permeability
◦ Functions
◦ Regeneration
◦ role of JE in initiation of pocket formation
◦ Junctional epithelium around implants
CONTENTS

3.  Gingival fiber
◦ Classification
◦ Features
◦ Functions
 Biologic width
 Conclusion

4. INTRODUCTION
 Teeth are trans-mucosal organs.
 This is a unique association in the human
body where a hard tissue emerges through
the soft tissue.
 The tooth-epithelial interface is a specialized
structural and functional adaptation

5.  Sicher H, 1959:The dentogingival unit (DGU) has
been described as a functional unit composed of the
epithelial attachment and connective tissue
attachment of the gingiva – both of which afford
biological protection .
 Listgarten MA, 1970:Dento-gingival unit refers to
the functional unit comprising of junctional
epithelium and the gingival fibers.
DEFINITION

6.  “Physiological DGU” is the anatomical complex
formed by the gingival margin, sulcus,
junctional epithelium and connective tissue
attachment.
 The epithelial attachment measures 0.97 mm
 The connective tissue attachment 1.07 mm
Gargiulo et al. 1961
Gingival fibers
Junctional epithelium
Dento
gingiva
l unit

7.  The attachment of junctional epithelium to tooth is reinforced
with gingival fibers, which brace the gingiva against tooth
surface.
gingival fibers & junctional epithelium
functional unit
Dentogingival unit

8.  The oral epithelium around a tooth is divided into
three functional compartments– gingival, sulcular,
and junctional epithelium
 The gingival epithelium extends from the
mucogingival junction to the gingival margin
where crevicular/sulcular epithelium lines the
sulcus
 At the base of the sulcus connection between
gingiva and tooth is mediated with
JUNCTIONAL EPITHELIUM

9. Three zones of the gingival epithelium
Crevicular (sulcular)
epithelium -1. 8mm
Oral epithelium -
Junctional
epithelium
1.35mm

10. JUNCTIONAL EPITHELIUM

11.  The dentogingival junction is the
interface between the mineralized
tissue of a tooth and the gingiva. In
this region, an unusual stratified
integument called the junctional
epithelium makes a tight seal against
the mineralized tooth surface via a
structural complex termed the
epithelial attachment (Schroeder,
1986;Rateitschak et al., 1989).
DEFINITION

12. HISTORY
• Gottlieb (1921) was the first to describe the junctional
epithelium
• Schroeder and Listgarten (1977) clarified the anatomy
and histology of the dentogingival junction

13.  Formed from oral epithelium and reduced enamel
epithelium.
 Shortly before 1st contact a slow cell transformation
 Beginning orally and ending at CEJ,
1 to 2 yrs ( Schroeder & Listgarten 1977)
3 to 4 yrs (Tencate 1998)
 REE gradually multilayer non keratinizing
converts to squamous epithelium
DEVELOPMENT OF JUNCTIONAL
EPITHELIUM

14. JUNCTIONAL EPITHELIUM ON AN
ERUPTING TOOTH.
The junctional epithelium (JE) is formed by the
joining of the oral epithelium(OE) and the
reduced enamel epithelium (REE).
Afibrillar cementum, sometimes formed on
enamel after degeneration of the REE
The arrows indicate the coronal movement of the
regenerating epithelial cells, which multiply
more rapidly in the JE than in the OE.
E, Enamel; C, root cementum.
A similar cell turnover pattern exists in the fully
erupted tooth.

15.  During transformation process,
Reduced ameloblasts undergo structural change
short columnar flattened cells that
orient parallel to
enamel surface

16. Structure of junctional epithelium
 Anatomical aspects
 Junctional epithelium and interstitial cells
 Epithelial attachment

17. Anatomical aspects
 part of marginal free gingiva
 Forms a collar like band
 Interproximal area fuse to form
epithelial lining of interdental col
 The coronal termination of the
junctional epithelium corresponds
usually to the bottom of the
gingival sulcus.

18. JE and Interstitial cell
 JE is a collar-like band of nonkeratinised stratified
squamous epithelium extending from cemento-enamel
junction to bottom of gingival sulcus
 Coronally it is 3-4 cell layers thick , increase upto 10-20
layers with age and apically narrows to 1-2cells
 Its length varies from 0.25 – 1.35mm

19. stratum basale ( towards CT)
 Made up of 2 strata
stratum suprabasale
(facing tooth surface)
 Organelles- lysosomal bodies, free ribosome, prominent
membrane bound structure, i.e. golgi complex,
cytoplasmic vacuoles, polyribosomes, cisternae of RER
are abundant.
 Cells are connected by Desmosomes.
 Fluid filled intercellular spaces may vary in width.

20.  All JE cells express unique set of cytokeratins
K5, 14, 19 & occasionally K8, 18.
 Lacks K6,16
 JE is only stratified non keratinized tissue that
does not synthesize K4, K13. Morgan et al.
 Lysosomelike bodies are present, but the
absence of keratinosomes(Odland bodies)
and histochemically demonstrable acid
phosphatase, correlated with the low degree
of differentiation, cause low defense power
against microbial plaque accumulation in the
gingival sulcus.

21. EPITHELIAL ATTACHMENT APPARATUS
 The term epithelial attachment refers to the attachment
apparatus, i.e. internal basal lamina
& hemidesmosomes
that connects the junctional epithelium to the tooth
surface.
 Connected with gingival connective tissue by external
basal lamina.
 Hemidesmosomes at the plasma membrane of the DAT
(Directly attached cells) directly attached to the tooth
and internal basal lamina( lamina lucida), is present on
the tooth surface

22. N-nucleus of a DAT cell,
IF-cytoplasmic keratin filaments
The hemidesmosomes at the plasma
membrane are associated with the α6 ,β4
integrin that communicates with laminin 5
located mainly in the internal basal lamina, the
extracellular domain for B180 (collagenous
protein type VIII), that has not yet been
definitely characterized.
LL = lamina lucida,
LD = lamina densa,
SLL = sub lamina lucida,
IBL = internal basal lamina.
STRUCTURAL AND MOLECULAR COMPOSITION OF
THE EPITHELIALATTACHMENT APPARATUS AT DAT
CELL

23.  Hemidesmosome act as specific site of
signal transduction thus participate in
regulation of gene expression, cell
proliferation, cell differentiation.
 Organic strands from the enamel appear
to extend into the lamina densa. Stern
IB,1967
 The junctional epithelium attaches to
afibrillar cementum present on the crown
(usually restricted to an area within 1 mm
of the cementoenamel
junction,Schroeder HE, Listgarten
MA,2000) and root cementum in a
similar manner.

24.  Histochemical evidence for the presence
of neutral polysaccharides in the zone of
the epithelial attachment.
 The basal lamina of the junctional
epithelium resembles that of endothelial
and epithelial cells in its laminin content
but differs in its internal basal lamina,
which has type IV collagen .
Bowers,1963
 These findings indicate that the cells of
the junctional epithelium are involved in
the production of laminin and play a key
role in the adhesion mechanism.

25. HISTORICAL CONCEPTS OF
ATTACHMENT
 Gottlieb (1921)
 Waerhaug (1952)
 Orban (1953)
 Waerhaug (1960)
 Listgarten (1966)
 Schroeder and Listgarten (1971)

26. Gottlieb’s concept (1921)
 Soft tissue of gingiva is organically united to enamel
surface.
 He termed the epithelium contacting the tooth “epithelial
attachment”.

27. Orban’s concept (1953)
 He stated that the separation of the epithelial attachment
cells from the tooth surface involved preparatory
degenerative changes in the epithelium.

28. Waerhaug’s concept (1960)
 He presented the concept of epithelial cuff. This concept
was based on insertion of thin blades between the
surface of tooth and the gingiva
 Blades could be easily passed apically to the connective
tissue attachment at CEJ without resistance.
 It was concluded that gingival tissue and tooth are
closely adapted but not organically united.

29. Schroeder and Listgarten concept
(1971)
 The previous controversy was resolved after evolution
of transmission electron microscopy.
 Primary epithelial attachment refers to the epithelial
attachment lamina released by the REE. It lies in direct
contact with enamel and epithelial cells attached to it by
hemi-desmosomes.
 When REE cells transform into JE cells the primary
epithelial attachment becomes secondary epithelial
attachment . It is made of epithelial attachment between
basal lamina and hemi-desmosomes.

30.  The junctional epithelium faces both the gingival
connective tissue (i.e., the lamina propria of the gingiva)
and the tooth surface
JE
EPITHELIAL ATTACHMENT AT
MOLECULAR LEVEL

31.  Basement membrane – specialized extracellular matrix
 Functions-
a. Compatmentalization
b. Filtration(selective permeability barrier function)- allow access
of gingival fluid, inflammatory cells , component of
immunologic host defence to gingival margin,
c. Cell polarization, migration.
d. Cell adhesions (production of laminin)
e. Cell differentiation(rapid turn over – tissue repair, host parasite
eqquilibrium
f. Prevent pathogenic bacteria from colonizing subgingivally
g. Barrier agains plaque bacteria
h. Endolytic capacity like macrophages, neutrophils.

32.  consists of lamina lucida
lamina densa
lamina fibroreticularis
 Typical matrix constituents of basement membrane
1. Collagen types IV & VII
2. Laminin
3. Heparan sulfate
4. Fibronectin
5. Nidogen
6. Proteoglycan
7. perlecan

33. SCHEMATIC DEPICTION OF THE DETAIL
OF THE INTERNAL BASAL LAMINA
It consists of two layers: the
lamina lucida and lamina
densa.
Hemidesmosomes (HD)
originate from the lamina
lucida, and tonofilaments
splay out from each
hemidesmosome.

34.  The internal basement membrane is 80-120nm wide
homogeneous layer facing enamel, with an intervening
laminated or non-laminated layer of cuticles (Listgarten,
1966) or afibrillar cementum (Kobayashi et al., 1976).
 There are numerous fine strands crossing the lamina
densa of the internal basement membrane at the
hemidesmosomes. These strands may have been the
anchoring filaments of hemidesmosomes (Eady, 1994;
Garrod, 1993).
 In the cytoplasm of the cells of the junctional epithelium,
the tonofibrils are associated with hemidesmosomes.

35.  The internal basement membrane of the dentogingival
border is uniquely specialized for mechanical strength,
sealing off the periodontal tissues from the oral
environment (Sawada & Inoue, 1996).
 This is a band of multilayered thick basement membranes
 The finer level structure of the internal basement
membrane is, the “cord” network. The basic texture of the
lamina densa is made up of a 3-dimensional network
formed by anastomosing, irregular, thread-like structures
referred to as “cords” (Inoue, 1994; Sawada & Inoue,
2001).


36. INTERNAL BASEMENT MEMBRANE
Internal basement membrane is
composed of broad band like
lamina densa
Internal basement membrane is
composed of multi-layers
of lamina densa

37.  Lamina densa is composed of fine
network of irregular anastomosing
cords

38. MECHANISM OF BINDING OF NORMAL TOOTH
TO GINGIVA THROUGH CORD LIKE
STRUCTURES IN LAMINA DENSA
 The lamina densa of the internal basement membrane is
closely associated with an additional layer referred to as
the supplementary lamina densa on the enamel side of
the tooth.
 One part of the basement membrane, the supplementary
lamina densa, is mineralized. This mineral deposit is
continuous with that of the enamel of the tooth, and thus
this deposit on the supplementary lamina densa forms an
advancing edge of mineralization.
(Sawada & Inoue,
2003)

39.  In the mineralized portion of the lamina densa, mineral
crystals were arranged in a network pattern which was
comparable to the pattern of the cord network.
 This may facilitate more powerful gripping, and
demonstrates the elaborate mechanism by which firm
binding of the mineral and organic phases is achieved.

40. DENTO-GINGIVAL BORDER OF
TOOTH FROM DEMINERALIZED AND
NON-DEMINERALIZED SAMPLES
DEMINERALIZED SECTION
SHOWING THE EMPTY SPACE
OF SUBLAMINA DENSA
MINERALISED SECTION SHOWING
MINERALISED SUBLAMINA DENSA
LUCIDA CONTINUOUS WITH
ENAMEL

41.  Cells and extracellular dynamics of JE
– essential for its protective &
regenerative function.

42.  Exfoliation must occur at extremely high rate ( Loe & Karring
1969)
 Since DAT cells are connected to basal lamina via
hemidesmosomes, a remodelling of epithelial attachment must
occur.
 Thus epithelial attachment normally is not static but dynamic.
 Intercellular spaces of JE
provides pathway for fluid & transmigratory leukocytes
a variety of molecules + leukocytes ( host defense system)

43. Expression of various molecules and their
function
 JE cells have surface or cell membrane molecules that
play a role in cell matrix and cell-cell interactions. JE
cells express numerous cell adhesion molecules
(CAM’s), such as integrins and cadherins.
 Knowledge about structure and molecules involved in
the maintenance of cell-cell contact is particularly
important in view of the pathological changes that the
epithelium undergoes during its conversion to a pocket
lining.

44.  Integrins – are cell surface receptors that mediate interactions
between cell and extracellular matrix, and also contribute to
cell to cell adhesion.
 The cadherins are responsible for tight contacts between cells.
 E-cadherin, an epithelium specific cell adhesion molecule,
plays a crucial role in maintaining the structural integrity.
 Intercellular adhesion molecule-1(ICAM-1 or CD-54) and
lymphocytic function antigen- 3(LFA-3) are additional cell
adhesion molecules.
 Cells in contact with the internal basal lamina express the
integrins.

45.  (CEACAM1)—a transmembrane cell-adhesion molecule that
is expressed on leukocytes, epithelia, and blood vessel
endothelia .
 high expression of interleukin-8 (IL-8), a chemotactic
cytokine, is seen in the coronal-most cells of the junctional
epithelium
 interleukin-1α (IL-1α),
 interleukin-1β (IL-1β),
 tumor necrosis factor-α (TNF-α)—are strongly expressed in
the coronal half of the junctional epithelium
 N-acetyllactosamine—the type 2 chain H precursor of the
blood group A-specific carbohydrate, which is usually
associated with the lowest level of cell differentiation.

46.  Antimicrobial molecules--- α and β defensins
cathelicidin family
calprotectin

47. DYNAMICS (TURNOVER RATE) OF JE
 The turnover rate of JE cells is exceptionally rapid. In
non-human primates it is about 5 days (twice that of oral
epithelium).
 The DAT cells express a high density of transferrin
receptors supporting the idea of active metabolism and
high turnover.
 DAT cells have an important role in tissue dynamics and
reparative capacity of the JE.
 The existence of a dividing population of DAT cells in a
suprabasal location in several layers from connective
tissue is a unique feature of JE.

48. Mechanism of JE cells turnover
(1)The daughter cells are produced by
dividing DAT cells and replace
degenerating cells on the tooth surface.
(2) The daughter cells enter the exfoliation
pathway and gradually migrate coronally
between the basal cells and the DAT cells
to eventually break off into the sulcus, or
(3)Epithelial cells move/migrate in the
coronal direction along the tooth surface
and are replaced by basal cells migrating
round the apical termination of the
junctional epithelium.
E

49. PERMEABILITY OF JUNCTIONAL
EPITHELIUM
• The bi-directional arrows indicate that
the junctional epithelium is the most
permeable portion of the gingival
epithelia.
• Because of its permeability to
bacterial products and other assorted
antigens, the connective tissue
adjacent to the junctional epithelium
tends to become infiltrated with
chronic inflammatory cells, primarily
lymphocytes and plasma cells.

50. FUNCTIONS OF JUNCTIONAL
EPITHELIUM
 Has attachment role and protective role.
 Permeability allows GCF and defence cells to pass
across to protect underlying tissues from disease
processes (periodontal disease).
 GCF contains gamma globulins and poly-
morphonuclear leukocytes (PMNs) giving it
immunological /phagocytic properties to combat disease
processes.
 Such molecules pass readily across JE to underlying
tissues.

51.  JE may contain neutrophils & other inflammatory cells
indicating disease & state of health of periodontium.
 Cell polarization, migration.
 Cell adhesions (production of laminin)
 Cell differentiation –Rapid turn over

52.  Helps maintaing integrity of tooth/periodontium
structure
 The junctional epithelium plays a crucial role since it
essentially seals off periodontal tissues from the oral
environment.
 Its integrity is thus essential for maintaining a healthy
periodontium.

53. JE in antimicrobial defense
(1) JE cells exfoliate because of rapid cell
division
(2) Funnelling of junctional epithelial cells
towards the sulcus hinder bacterial
colonization.
(3) Active antimicrobial substances are
produced in junctional epithelial cells.
(4) Epithelial cells activated by microbial
substances secrete chemokines,
(5) Chemokines attract and activate
professional defense cells, PMN.

54.  ROLE OF JE IN POCKET
FORMATION

55. Role of JE in the initiation of pocket formation
 Conversion of the JE to pocket epithelium is regarded as
a hallmark in the development of periodontitis.
 Schroeder – 1996 pointed to a biologically relevant and
clinically important question that still awaits resolution:
‘what happens to the JE under conditions of sub-
gingival microbial attack i.e. in context with pocket
formation and deepening?’

56.  Schluger et al 1977: Pocket formation is attributed to a loss
of cellular continuity in the coronal most portion of the JE
 Thus the initiation of pocket formation may be attributed to
the detachment of the DAT cells from the tooth surface or to
the development of intraepithelial split.
 Schroeder and Listgarten 1977: An increased number of
mononuclear leukocytes (T and B cells, macrophages)
together with PMNs are considered as factors contributing to
the disintegration of the JE.
 Takata and Donath (1988) observed degenerative changes in
the second or third layer of the DAT cells in the coronal most
portion of the JE cells facing the biofilm.

57. The degeneration and
detachment of DAT cells
exposes tooth surface and
creates a sub-gingival niche
suitable for the colonization
of anaerobic gram-negative
bacteria and apical growth of
dental plaque.

58.  Hintermann et al 2002: Gingipains degrade the epithelial
cell-cell junctional complexes and cells exposed to
proteinases derived from P.gingivalis showed reduced
adhesion to extracellular matrix.
 Destruction of cell-cell and cell to ECM attachment
degrade the structural and functional integrity of the JE.

59.  REGENERATION OF JE
• Injury to JE may occur due to intentional or
accidental trauma.
• Accidental trauma can occur during probing,
flossing or tooth margin preparations for
restorations.
• Intentional trauma occurs during periodontal
surgeries where the JE is completely lost.

60.  Many studies have been done to investigate the
renewal of JE.
 These include - renewal of JE on tooth and
implant surface after mechanical detachment by
probing.
 Mechanical trauma during flossing and on
regeneration of JE after gingivectomy procedure
which completely removes JE.

61.  Taylor and Campbell 1972: A new and complete
attachment indistinguishable from that in control was
established 5 days after complete separation of the JE
from the tooth surface.
 Frank et al 1972: A study demonstrated that newly
differentiated attachment apparatus with normal
hemidesmosomal attachment is possible following
surgery. This new attachment apparatus was seen on
cementum as well as dentin.

62.  Listgarten 1972: Hemidesmosomes appeared to form prior to
the basal lamina. The basal lamina is initially formed in close
proximity to the hemidesmosomes at both the tooth and
connective tissue interface.
 At 4 to 7 weeks, the basal lamina appeared complete.
 Studies have shown that regeneration of JE after procedure
usually occurs within 20 days.

63.  JE AROUND IMPLANTS

64.  The junctional epithelium around implants always
originates from epithelial cells of the oral mucosa, as
opposed to the junctional epithelium around teeth which
originates from the reduced enamel epithelium.
 Despite different origins of the 2 epithelia, a functional
adaptation occurs when oral epithelia form an epithelial
attachment around implants.

65. NATURAL TOOTH
 Epithelium tapers
towards the depth
 Large number of
cell organelles
 Fibers are
arranged
perpendicular
IMPLANT
• Epithelium is
thicker
•Few organelles
•Fibers are arranged
parallely
•Numerous kerato-
hyalin granules

66. NATURAL TOOTH IMPLANT

67. GINGIVAL FIBERS

68. Gingival Fibers
 The connective tissue of the marginal
gingiva is densely collagenous,
containing a prominent system of
collagen fiber bundles called the
gingival fibers.

69. THE GINGIVAL FIBER APPARATUS
 The gingival lamina propria consists mainly of a
dense network of collagen fiber bundles that
account for about 55.43% of the connective
tissue volume. This network is called the
supragingival fiber apparatus.
 On the basis of their preferential orientation,
architectural arrangement and sites of insertion,
these bundles have been classified.

70.  These fiber bundles are densely populated by fibroblasts
and consist mainly of collagen Type I and III.
 Collagen Type I represents mainly dense fibers; Type III is
related to loose connective tissue, subepithelially and
around blood vessels.
 Mast cells are also regular residents, whereas
lymphocytes, monocytes and macrophages vary in
number with the need for and degree of protective
activity.

72. CLASSIFICATION OF GINGIVAL FIBER GROUPS
based on their orientation , sites of insertion, the
structures that they connect gingival fibers are
classified as-
GINGIVAL FIBERS
PRIMARY FIBERS SECONDARY FIBERS

74. PRIMARY FIBERS:
• Alveologingival fibers
• Circular fibers.
• Dentogingival fibers

75.  Alveologingival fibers—extend from the periosteum of
the alveolar crest into the gingival connective tissue.
These fiber bundles attach the gingiva to the bone. (The
periosteum is a dense membrane composed of fibrous
connective tissue that closely wraps around the outer
surface of the alveolar bone.)
 Circular fibers—encircle the tooth in a ring-like
manner coronal to the alveolar crest and are not
attached to the cementum of the tooth. These fiber
bundles connect adjacent teeth to one another.
 Dentogingival fibers— are embedded in the cementum
near the CEJ and fan out into the gingival connective
tissue. These fibers attach the gingiva to teeth.

76. SECONDARY FIBERS
 Periostogingival fibers.
 Intergingival fibers
 Intercircular fibers
 Interpapillary fibers
 Transseptal Fibers-
1. Transgingival fibers
2. Semicircular fibers
- Page et al(1972)

78. Transseptal fibers
 Located interproximally,
 The transseptal fibers form horizontal
bundles that extend between the
cementum of approximating teeth into
which they are embedded.
 They lie in the area between the
epithelium at the base of the gingival
sulcus and the crest of the interdental
bone

79.  Page et al1972 described
 (1) a group of semicircular fibers, which is
attached at the proximal surface of a tooth,
immediately below the cementoenamel junction,
go around the facial or lingual marginal gingiva of
the tooth, and attach on the other proximal surface
of the same tooth; and
 (2) a group of transgingival fibers, that attach in
the proximal surface of one tooth, traverse the
interdental space diagonally, go around the facial
or lingual surface of the adjacent tooth, again
traverse diagonally the interdental space, and
attach in the proximal surface of the next tooth.

80. Functions of the Gingival Fiber Bundles
1. Brace the marginal gingiva firmly against the tooth
and reinforce the attachment of the JE to the tooth.
2. Provide the rigidity necessary to withstand the
forces of mastication without being deflected away
from the tooth surface
3. Unite the free marginal gingiva with the cementum
of the root and adjacent attaced gingiva.
4. Connect adjacent teeth to one another to control
tooth positioning within the dental arch.

81. THE SUPRAGINGIVAL FIBER APPARATUS
 The formation and insertion of transseptal and
dentogingival fibers is not specific to certain
anatomic surfaces, but is functionally rather than
anatomically determined.
 The supragingival fiber apparatus not only attaches
the gingiva to teeth and bone but also provides a
dense framework that accounts for the rigidity and
biomechanical resistance of the gingiva.
 The fiber apparatus also controls the positioning of
teeth within the dental arch and also protects the
very sophisticated cellular defenses located at the
dentogingival interface.

82. SUPRAGINGIVAL FIBERS AROUND
IMPLANTS

83. BIOLOGICAL WIDTH

84.  BIOLOGIC WIDTH is defined as the dimension of the soft
tissue which is attached to the portion of the tooth coronal to
the crest of the alveolar bone
 JUNCTIONAL EPITHELIUM CONNECTIVE TISSUE
BIOLOGIC WIDTH
 It is important from the restorative point of view because its
violation leads to complications like gingival enlargement
alveolar bone loss and improper fit of the restoration.
 The average combined histological width of connective tissue
attachment and junctional epithelium was 2.04mm, which is
referred to as the BIOLOGIC WIDTH.

85. Average human biologic width: Connective tissue attachment
1 mm in height; epithelial attachment 1 mm in height;
sulcus depth of approximately 1 mm. The combined connective
tissue attachment and epithelial attachment or biologic width
equals 2 mm.

86.  Gargiulo et al (1961) in their study described the
dimensions and relations of dentogingival junction in
humans. The average histological width of connective
tissue attachment was 1.07mm. The mean average length
of epithelial attachment was 0.97mm with the range of
0.71mm-1.35mm.
 They reported biologic width as 2mm but found as
narrow as 0.75mm to even 4.3mm in some patient.
 Vacek et al, 1994 found average biologic width as 2mm

87. CONCLUSION
 DENTOGINGIVAL UNIT is important because of its
anatomical location.
 It is the site of host-bacterial interaction in initiation of
periodontal disease.
 There is a constant presence of bacteria and their
products in the gingival sulcus which makes this an
important structural component of periodontal defense
mechanism.
 The conversion of the junctional epithelium to pocket
epithelium is regarded as hallmark in the development of
periodontitis.

88. THANK YOU