STRUCTURAL AND METABOLIC CHARACTERISTIC OF GINGIVAL EPITHELIUM

1
STRUCTURAL AND METABOLIC CHARACTERISTIC OF
GINGIVAL EPITHELIUM

• Gingival epi-
• Oral/ Outer
• Sulcular
• Junctional

2
OUTER OR ORAL EPITHELIUM

• - Covers the crest and outer surface of the
  marginal gingiva and the surface of attached
  gingiva.
• - Thickness - 0.2-0.3 mm
• - Keratinized or parakeratinized.
• -Keratinization diminishes with age onset
  of menopause

3
Order of keratinization-

• palate gt gingiva gt ventral aspect of tongue gt
  cheek

4

• Keratins K1, K2 K10-K12 which are specific to
  epidermal differentiation, seen more in
  orthokeratinized than parakeratinized.
• K6 K16 characteristic of highly proliferative
  epithelia,K5 K14, stratification-specific
  cytokeratins,are also present.
• K19 present in parakeratinized,absent in
  orthokeratized.

5
SULCULAR EPITHELIUM

• Lines the gingival sulcus
• Non keratinized
• SSE without rete pegs
• Extends from coronal limit of junctional
  epithelium to the crest of gingival margin.
• Shows hydropic degeneration.

6

• Contain K4, K13 (Oesophageal type cytokeratin)
• - K19
• No Merkel cell
• Glu-6-phosphate dehydrogenase activity is less.
• Acid phosphatase is totally absent
• Lower degree of activity in sulcular epi than in
  outer epi particularly in the case of enzymes
  related to keratinization.

7
Sulcular epithelium has the potential to
keratinize if-

1. If it is reflected and exposed to oral cavity.
2. The bacterial flora is totally eliminated.

8

• Sulcular epithelium is extremely imp - it may act
  as a semipermeable memb via which injurious
  bacterial products passing to the gingiva
  tissue fluid from the gingiva seeps into the
  sulcus.

9

• Unlike the junctional epithelium
• - sulcular epithelium is not heavily infiltrated
  with PMNs.
• - Less permeable

10
Junctional Epithelium

• Consists collar like band of SSE.
• Nonkeratinized
• 3-4 layers thick in early life,
• 10-20 layers thick with increase in age.
• Tapers from its coronal end.
• Length 0.25-1.35mm.
• Express K19,
• K5, K14

11

• The cells can be grouped in to two strata-
• JE is formed by the confluence of oral
  epithelium and the reduced enamel epithelium
  during tooth eruption.
• The JE is attached to the tooth surface
  (epithelial attachment) by means of internal
  basal lamina. It is attached to gingival
  connective tissue by an external lamina.

12

• The attachment of the JE to the tooth is
  reinforced by the gingival fibers which brace the
  marginal gingiva against the tooth surface, so
  the JE and gingival fibers are considered a
  functional unit K/A DENTOGINGIVAL UNIT.
• Dentogingival unit JE Gingival fib

13
FUNCTIONS OF JE

• JE is firmly attached to the tooth surface,
  forming an epithelial barrier against plaque
  bacteria.
• It allows access of gingival fluid ,
  inflammatory cells and components of
  immunological host defense to the gingival
  margin.
• exhibit rapid turnover, which contributes to the
  host-parasite equilibrium and rapid repair of
  damaged tissue.
• cells of JE have endocytic capacity equal to
  that of macrophage and neutrophils and that this
  activity might be protective in nature.

14
Cuticular structure on the tooth

• Cuticle
• Acquired coating (exogenous
  origin)
• Developmental - (part of
  tooth)

15
thank you