Saliva Periodontics Important Question And Answers

Saliva

Saliva is essential for maintaining the integrity of oral tissues. It acts as a mirror of oral and systemic health and hence could be used to monitor the general health and the onset of specific diseases.

Most of the salivary secretion is contributed by the major salivary glands (parotid, submandibular, and sublingual) while some of it is by the minor salivary glands.

Question 1. Describe the composition of saliva.
Answer:

Saliva is an exocrine secretion comprising of 99% water and 1% inorganic and organic substances.

• Saliva is produced in the human body in quantities of 1000 to 1500 mL per day. pH of saliva is 6.35–6.85.
• Saliva that is expressed at rest is called unstimulated saliva, which covers, moisturizes, and lubricates the oral cavity.

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• However, 90% of daily salivary secretion is produced on stimulation in response to either gustatory, olfactory, mechanical, or pharmacological stimulus.
• Organic substances- proteins in the form of glycoproteins; gamma-globulins, statins, albumin, and enzymes.
• Inorganic substances- calcium, phosphorous, sodium, potassium, magnesium
  • Electrolyte: Bicarbonate, calcium, fluoride, phosphate enzymes: α-amylase, invertase
  • Mucins
  • Immunoglobulins: IgA, IgG, IgM, IgAs
  • Lipids: Neutral lipids, glycolipids, phospholipids
  • Proteins: Proline-rich proteins, salivary agglutinins, statherin, histidine-rich proteins, lactoferrin, lysozyme.

Question 2. What are the functions of saliva?
Answer:

1. Digestive:

• Taste
• Digestion of food
• Bolus formation.

2. Protective:

• Remineralization of enamel- using calcium and phosphorus ions
• Protection and lubrication of oral tissues
• Buffing
  • Bicarbonates and phosphates buffer bacterial acids and food Cleansing of oral cavity

3. Defense mechanism:

• Immunologic
  • IgA prevents the attachment of microorganisms to tooth and oral mucosa
  • Leucocytes- migrate in large numbers in saliva
• Antibacterial property
  • Lysozyme acts as a scavenger as it splits bacterial cell wall
  • Sialoperoxidase enzyme acts as an antibacterial against streptococci.

Question 3. Write a note on saliva as a diagnostic tool.

Answer:

• Collection of saliva is simple, non-invasive, and hence offers a cost-effective approach for the screening of large populations.
• Saliva contains biomarkers specific for determining the physiological state of periodontal health and disease.
• Any changes in these biomarkers could have diagnostic value by identifying patients with enhanced disease susceptibility, identifying sites with active disease, and monitoring the effectiveness of therapy.
• Salivary biomarker detectors can be used for point-of-care (POC) disease screening and detection. They are developed as microchips and microfluidic platforms for POC testing.

Biomarkers in saliva are:

• Enzymes: Alkaline phosphatase, amino peptidase, trypsin, gelatinase, esterase, collagenase
• Immunoglobulin: IgA, IgG, IgM, IgA
• Protein: Cystatin, fibronectin, lactoferrin, vascular endothelial growth factors, platelet-activating factors (PDGF), epidermal growth factors (EGF)
• Host cell: Leukocytes (PMN’S)
• Ion: Calcium
• Hormones: Cortisol
• Bacteria: A.actinomycetemcomitans, P.gingivalis, P. intermedia, C. rectus, T.denticola, B.forsyth, P. micros
• Volatile compounds: Hydrogen sulfide, methyl mercaptan, picolines, pyridines
  • Markers of soft tissue loss: Prostaglandins, interleukins, MMP-8, 9 and 13
  • Markers of alveolar bone loss: MMp-8,9 and 13, alkaline phosphatase, osteocalcin, osteonectin collagen telopeptides (ICTP)