defence mechanism of gingiva saliva

1. By: William
BDS (Final Year)
DEFENCE
MECHANISM
OF GINGIVA -
SALIVA

2. CONTENTS
1. INTRODUCTION
2. EMBRYOLOGY
3. CLASSIFICATION OF SALIVARY GLANDS
4. MECHANISM OF FORMATION OF SALIVA
5. COMPOSITION
6. FUNCTIONS OF SALIVA
7. CONTROL OF SALIVATION
8. FACTORS AFFECTING COMPOSITION AND
SECRETION OF SALIVA
9. CO-RELATION BETWEEN SALIVAAND DENTAL
CARIES

3. 10. ROLE OF SALIVA IN ACQUIRED PELLICLE
FORMATION
11. ROLE OF SALIVA IN CALCULUS FORMATION
12. ROLE OF SALIVA IN SALIVARY GLAND DISEASE
13. METHODS OF SALIVA COLLECTION
14. SALIVARY MARKERS IN PERIODONTAL DISEASE
15. CLINICAL CONSIDERATIONS OF SALIVA
16. DISEASES OF SALIVARY GLANDS
17. CONCLUSION
18. REFERENCES

4. INTRODUCTION
◦ Saliva is one of the most important fluids in the human body.
◦ It helps to remove waste, supply nutrients & protect the cells.
◦ It is first digestive juice that comes in contact with food.
◦ Saliva is one of the major natural defence systems of the oral
cavity .

5. DEFINITION
◦ Saliva is a clear, tasteless, odorless, slightly acidic, viscous
fluid consisting of secretions from the parotid,
Submandibular & mucous glands of oral cavity.
Stedman’s Medical Dictionary
◦ Saliva is a clear, alkaline, somewhat viscous secretion from
the parotid, submandibular, sublingual & smaller mucous
glands of the mouth.
Dorland’s Medical Dictionary

6.  The secretions of the major and minor salivary glands together
with the gingival crevicular fluid, constitute the oral fluid or
whole saliva, which provides the chemical milieu of the teeth
and oral soft tissues. (Neubrun )
6
MAJOR
GLANDS
SALIVA
MINOR GLANDS
GCF
GCF

7. CLASSIFICATION OF SALIVARY
GLANDS
MAJOR SALIVARY
GLANDS
Parotid
Gland
Submandibular Gland
Sublingual Gland
MINOR SALIVARY
GLANDS
Lingual mucous
Lingual serous
Buccal glands
Labial glands
Palatal glands
(A) According to size and location

8. PAROTID GLAND
 Largest of all the salivary glands
 Saliva is delivered via Stensons duct
 Second largest salivary gland

9. SUBLINGUAL SALIVARY
GLAND
 Smallest of the major glands
Produce less than 5% of total saliva
output
Saliva delivered via the ducts of
Bartholin

10. (B) ACCORDING TO THE HISTOCHEMICAL
NATURE OF SECRETORY PRODUCTS
• This type of gland is made up of serous cells
predominantly.
• These glands secrete thin & watery saliva .
• Parotid glands and lingual glands are serous glands.
SEROUS GLANDS
• This type of glands are made up of mucous cells
mainly .
• These glands secrete thick & viscous saliva with more
mucin .
• Lingual mucous, buccal glands & palatal glands
belongs to this type.
MUCOUS GLANDS
• Mixed glands are made up of both serous and
mucous cells .
• Submandibular , sublingual & lacrimal glands
are mixed glands
MIXED GLANDS

11. FORMATION OF SALIVA
11

12. COMPOSITION OF SALIVA
◦ Organic -60%
◦ Inorganic-40%
◦ Water : 99.5%
12

13. ORGANIC CONSTITUENTS
Glycoproteins
Enzymes
o Amylase (ptyalin)
o Lysozyme
o Peroxidase
o Lactoperoxidase – thiocyanate
o Lipase
o Lactoferin
13

14. Coagulation factor
Hormones
Lipids
Vitamins
Carbohydrates
Immunoglobulin ie. IgG, IgA, IgM are present
Mucous
14

15. INORGANIC COMPONENTS
◦ Sodium - 2-21 mmoI/L
◦ Potassium – 10-36 mmol/L
◦ Calcium – 1.2-2.8 mmol/L
◦ Magnesium – 0.08-0.5 mmol/L
◦ Chloride – 5-40mmol/L
◦ Bicarbonate – 25mmol/L
◦ Hydrogen phosphate – 1.4-3.9mmol/L
◦ Fluoride - <1m/Mol/L
15

16. PROPERTIES OF SALIVA
◦ Daily secretion: 700-1500ml / 24hrs
◦ Normal flow rate
Unstimulated: 0.2-0.3 ml/min
Stimulated : 1 – 2 ml/min
◦ Consistency : cloudy, colorless, opalescent fluid
◦ pH: 6.7 – 7.4
◦ Specific gravity : 1.002 -1.012
16

17. ◦Freezing point : 0.07°C - 0.34°C
◦Volume of secretion :
Parotid gland :20%
submandibular gland :65%
sublingual gland:5%
◦Viscosity :
Parotid gland :1.5
submandibular gland :3.4
sublingual gland:13.4
17

21. FUNCTIONS OF SALIVA
◦ Important for mastication and swallowing and for general oral
health and comfort.
CLEANSING ACTION
o A constant flow of saliva has a cleansing effect on the mouth &
teeth and helps in oral hygiene and prevents dental caries.
o Salivary amylase initiates the digestion of starch.
o Saliva is alkaline and is an effective buffer system.
LUBRICATION

22. FACILITATION OF SPEECH
◦ saliva lubricates the oral cavity for proper activation of
speech.
◦ Helps in excretinf certain heavy metals like lead and
iodine etc.
◦ Salivary antibodies are mainly of IgA class – to
aggregate specific bacteria and prevent their adhesion to
oral hard and soft tissue.

23. CONTROL OF SALIVATION
◦ Salivary glands are under the control of autonomic
nervous system and receive efferent nerve fibres from both
parasympathetic and sympathetic divisions of autonomic
nervous system.

24. Parasympathetic fibres to submandibular and
sublingual glands

25. Parasympathetic fibres to parotid gland

26. FACTORS AFFECTING FLOW
RATE
Protein
• high in
the
afternoon
Sodium and
chloride
• high in
the early
hours
1. DIURINAL VARIATION: Salivary flow exhibits diurinal
variation
Calcium
• high in
the night

27. 2. DURATION OF SALIVATION:
If salivary gland are stimulated for more than 3 min , the conc of the
components in saliva is reduced.
3. DIET:
-Fluoride content may increase in children drinking fluoridated water.
- Diet rich in protein increase blood urea level thus increase urea conc
in saliva.
27

28. 4. DIETARY FACTORS:
-functional salivary glandular activity is influenced by
mechanical and gustatory factors
e.g., copious salivary flow results from the smell of food
or new denture insertion
5. PLASMA COMPOSITION:
-increase in plasma aldosterone concentration lower the Na and
increases K conc.in saliva.
28

29. CO-RELATION BETWEEN SALIVA
AND DENTAL CARIES
◦ It is capable of regulating the pH of the oral cavity by
the help of its bicarbonate content as well as its
phosphate and amphoteric protein constituents.
◦ Increase in secretion rate usually results in an increase
in pH and buffering capacity.

30. ◦Because of its calcium and phosphate content,
it helps to maintain the integrity of teeth.
◦Tooth dissolution is prevented or retarded and
re-mineralization is enhanced by the presence
of copious salivary flow.
30

31. ◦ The flow of saliva can reduce plaque accumulation on
the tooth surface.
◦ The diffusion into plaque of salivary components such
as calcium, phosphate, hydroxyl and fluoride ions
enhances re-mineralization of early carious lesions.

32. •Lysozyme, lactoperoxidase and lactoferrin in saliva have
a direct antibacterial action on plaque.
•Salivary proteins could increase the thickness of the
acquired pellicle and so help to retard the movement of
calcium and phosphate ions out of enamel.
lysozyme
lactoperoxidase

33. ROLE OF SALIVA IN ACQUIRED
PELLICLE FORMATION
 Most of the organic and inorganic constituents of supra
gingival plaque are derived from saliva.
 Glycoproteins form the important component of pellicle
that initially coats the tooth surface.
 The inorganic components of supra gingival plaque such as
calcium, phosphorous and trace elements like sodium,
potassium & fluoride are derived from saliva.

34.  The hydroxyapatite surface has a predominance of negatively
charged phosphate group that binds with positively charged
particles in saliva.
 These glycoproteins bind with plaque forming bacteria.
 Glycoprotein bacterial interactions result in bacterial
accumulations on the exposed tooth surface.
 Glycoproteins also aid in the maintenance of integrity of
dental plaque.

35. ROLE OF SALIVA IN CALCULUS
FORMATION
 As the mineral content in the plaque mass increases it gets
calcified to form calculus.
 It is usually found in the areas of dentition adjacent to
salivary ducts. (lingual surface of mandibular anterior
&buccal surface of maxillary posteriors) reflecting high
conc of minerals available from saliva in those areas.

36.  Salivary proteins account for 5.9% to 8.2% of the organic
content of supra gingival calculus.
 Various proteins derived from saliva are glucose, galactose,
glucuronic acid, galactosamine
 Plaque has the ability to concentrate calcium 2 – 20 times its
level in saliva.
 A raise in the Ph of saliva causes precipitation of calcium
phosphate salts by lowering the precipitation constant.

37. METHODS OF SALIVA
COLLECTION

38. CLINICAL CONSIDERATIONS OF
SALIVA
1.HYPOSALIVATION
The reduction in the secretion of saliva is called hyposalivation. It is of two
types , namely
1)Temporary hyposalivation occurs in
i) emotional conditions like fear
ii) fever
iii) dehydration
2) Permanent hyposalivation occurs in
- sialolithiasis – obstruction of salivaary duct
- congenital absence or hypoplasia of salivary glands
- bell’s palsy – paralysis of facial nerve

39. 2.DRY MOUTH (XEROSTOMIA)
- It is a frequent clinical complaint
- loss of salivary function or a reduction in the volume of secreted
saliva may lead to the sensation of oral dryness.
- occurs as a side effect of mediations taken by the patient for other
problems.
- Many drug cause central or peripheral inhibition off salivary
secretion.
- Loss of gland function occurs after radiation therapy for head and
neck cancer

40. TREATMENT (SIALOGOGUES)
 Oral Spray
◦ Oasis: 1-2 sprays
NOT TO EXCEED 60 SPRAYS/DAY
◦ Aquoral
2 SPRAYS TID
 Oral Solution
◦ Caphosol: packaged in two 15 mL ampules when mixed together provide
one 30 mL dose
SWISH AND SPIT; NOT TO EXCEED 10 DOSES/DAY

41.  Lozenge-Saliva Sure
DISSOLVE IN MOUTH, NOT TO EXCEED 16 LOZENGES/ DAY
 Adhering disc- XyliMelts
APPLY 2 DISCS BEFORE BED, 1 ON EACH SIDE OF THE MOUTH
SWALLOW AS IT SLOWLY DISSOLVES

42. ANTISIALOGOGUES
◦ Reduces the salivary secretion
◦ APPLICATIONS:
 surgeries of salivary glands and ducts
 intra-oral procedures
 gingival retraction
 sialocele reduction and salivary gland healing
E.g., Atropine, anticancer drugs, antihistaminincs

43. 3)SJOGREN’S SYNDROME
◦ chronic autoimmune disorder characterized by xerostomia
(dry mouth), xerophthalmia (dry eyes), and lymphocytic
infiltration of the exocrine glands.
◦ This triad is also known as the sicca complex.
◦ autoimmune disorder in which the immune cells destroy
exocrine glands such as lacrimal glands & sweat glands .

44. ◦ named after HENRIK SJOGREN
◦ causes dryness of skin , nose.
◦ severe condition the organs like kidneys ,lungs,
liver , pancreas , thyroid , blood vessels & brain are
affected

45. 4) AGE CHANGES
With age a generalized loss of gland parenchymal tissue occurs.
The lost salivary cells often are replaced by adipose tissue
5) CARIES
a major problem of a reduced salivary flow saliva normally washes
away acids.
There may be an increase in recurrent decay on coronal as well as
root surfaces.
Incisal edges of Anterior teeth may also develop carious lesions as
well as recurrent lesions on the margins of restorations.

46. 6) DENTAL EROSION
Low buffering capacity and flow rate indicate a greater erosion
risk and advice should be given to the patient to minimise this.
This should include following acidic intake with a glass of water
to aid clearance and finishing each meal with a neutral salivary
stimulant, such as cheese, to promote salivary flow.
Chewing sugar-free gum also stimulates production of saliva.

47. 7)GINGIVITIS
 lack of saliva leads to retention of food particles in the mouth,
particularly interdentally and under dentures.
This may result in gingivitis and, in the long term, periodontitis
8) ORAL ULCERATION
reduced saliva flow may result in recurrent aphthous ulceration,
pain, lichen planus, delayed wound healing and secondary
infection, such as candidiasis.

48. 10) HALITOSIS
Saliva gives rise to bad odours especially during mouth breathing prolonged
talking or hunger
Eating reduces halitosis partly because it increases saliva flow and friction in the
mouth.
9) MUCOSITIS
 painful condition where the mucous membrane of the oral cavity becomes
ulcerated and inflamed
 It increases susceptibility to fungal infections such as candidiasis.
 lead to dysphagia, dehydration and impaired nutrition.

49. 11) HYPERSALIVATION
excess secretion of saliva
Hypersalivation in pathological condition is known as ptyalism ,
sialorrhea , sialism or sialosis.
Occurs in:-
1) Decay of tooth or neoplasm of mouth or tongue due to continuous
irritation of nerve endings in the mouth
2) Disease of esophagus , stomach & intestine
3) Neurological disorder such as cerebral palsy & mental retardation

50. 12) DROOLING
 Uncontrolled flow of saliva outside the mouth
often called ptyalism.
occurs because of excess production of saliva in association
with inability to retain saliva within the mouth.
Drooling in small children is a normal part of development.
 Teeth are coming in, they put everything in their little mouths,
and they haven’t developed the habit of keeping the lips
together.

51. 13) CHORDA TYMPANI SYNDROME
◦ characterized by sweating while eating
◦ During the regeneration of the nerve fibers following trauma or
surgical division, which pass through chorda tympani branch of
facial nerve may deviate & join with the nerve fibers supplying
sweat glands

52. 14)FREY'S SYNDROME or GUSTATORY SWEATING
◦ Baillarger’s syndrome, Dupuy’s syndrome, Auriculotemporal
syndrome or Frey-Baillarger syndrome)
◦ food related syndrome which can be congenital or acquired
specially after parotid surgery; persist for life.
◦ Symptoms: redness and sweating on the cheek area adjacent to
the ear.
◦ They can appear when the affected person eats, sees, thinks about
or talks about certain kinds of food which produce
strong salivation.

53. 15)PARALYTIC SECRETION OF SALIVA
 when the parasympathetic nerve to salivary gland is cut ,
salivary secretion increases for the first 3 weeks & later
diminishes
 finally it stops at about 6th week
The increased secretion of saliva after cutting the
parasympathetic nerve fibers is called paralytic secretion

54. 16)AUGMENTED SECRETION OF SALIVA
 if the nerve supplying salivary glands are stimulated twice , the
amount of saliva secreted by the second stimulus is more than the
amount secreted due to the first stimulus.
because , the first stimulus increases excitability of acinar cells , so
that when the second stimulus is applied , the salivary secretion is
augmented.

55. EFFECT OF DRUGS & CHEMICAL ON
SALIVARY SECRETION
1) Sympathomimetic drugs like adrenaline & ephedrine
stimulates salivary secretion
2) Parasympthomimetic drugs like acetylcholine ,
pilocarpine , muscarine & physostigmine increase the
salivary secretion
3) Histamine stimulates the secretion of saliva

56. 4) Parasympathetic depressants like atropine inhibit the
secretion of saliva
5) Anaesthetics like chloroform & ether stimulate the
reflex secretion of saliva However , deep anaesthesia
decrease the secretion due to central inhibition.

57. CONCLUSION
• Saliva is a complex secretion that plays a
major role in general and oral health and
disease
• It lubricates and protects the structures of
the mouth and influence the nature of oral
microbial flora and even the chemical
composition of teeth
• Saliva plays an important role in
formation of calculus and plaque and is
there intimately related to caries and
periodontal disease

58. REFERENCES
◦Human physiology BY AK Jain
◦Human Anatomy By BD Chaurasia
◦Carranza Clinical Periodontology 11th
edition
◦Oral Histology & Embryology- Orban’s 10th
edition