1.
By: William
BDS (Final Year)
DEFENCEMECHANISM
OFGINGIVA - SALIVA

2.
CONTENTS
1. INTRODUCTION
2. DEFINITION
3. CLASSIFICATION OF SALIVARY GLANDS
4. MECHANISM OF FORMATION OF SALIVA
5. COMPOSITION
6. PROPERTIES OF SALIVA
7. FUNCTIONS OF SALIVA
8. CONTROL OF SALIVATION
9. FACTORS AFFECTING FLOW RATE
10.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. CLINICAL CONSIDERATIONS OF SALIVA
16. EFFECT OF DRUGS $CHEMICAL ON SALIVARY
SECRETION
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

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
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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

18.
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

19.
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.

20.
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.

21.
Parasympathetic fibres to submandibular and sublingual
glands

22.
Parasympathetic fibres to parotid gland

23.
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

24.
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.
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25.
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.
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26.
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.

27.
28

28.
•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

29.
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.

30.
 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.

31.
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.

32.
 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.

33.
METHODS OF SALIVA
COLLECTION

34.
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
2) Permanent hyposalivation
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.

35.
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

36.
5) CARIES
saliva normally washes away acids.
Reduced salivary flow usually increases the incidence of caries.
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
Chewing sugar-free gum stimulates production of saliva.
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

37.
8) ORAL ULCERATION
reduced saliva flow may result in recurrent aphthous ulceration, pain, lichen
planus, delayed wound healing and secondary infection, such as candidiasis
9) 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.
10) HYPERSALIVATION
 excess secretion of saliva
 Hypersalivation in pathological condition is known as ptyalism , sialorrhea ,
sialism or sialosis.

38.
11) 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.

39.
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
4) Parasympathetic depressants like atropine inhibit the secretion
of saliva

40.
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

41.
REFERENCES
◦Human physiology BY AK Jain
◦Human Anatomy By BD Chaurasia
◦Carranza Clinical Periodontology 11th
edition
◦Oral Histology & Embryology- Orban’s 10th
edition

42.
THANKYOU