Saliva 4 -Inorganic components of Saliva

Question 1

What are the inorganic components of Saliva?

Answer 1

Sodium ions
Calcium ions
Magnesium ions
Bicarbonate ions
Protons 
Potassium ions
Phosphate ions
Hydroxyapatite 
Fluoride ions

Question 2

What is the role of calcium ions in saliva?

Answer 2

Required in saliva for HAP Mineralisation + Prevents dissolution
As flow inc. hard to detect change in calcium ions
- At very high rates calcium ion conc. Increases
- Hard to detect diff glands release diff amounts
Protein conc. inc. with flow rate new variable (as calcium binds to protein)

Question 3

What is the role of magnesium ions in saliva?

Answer 3

Decrease as salivary flow increases (dilution effect)
Unknown where derived from (may be burst cells or early carious attack)
Conc ranges from 0.2 – 0.5 mM

Question 4

What is the role of magnesium ions in saliva?

Answer 4

Decrease as salivary flow increases (dilution effect)
Unknown where derived from (may be burst cells or early carious attack)
Conc ranges from 0.2 – 0.5 mM

Question 5

What is the role of protons ions in saliva?

Answer 5

Not true inorganic component but very important in saliva
Maintains ionic product for HAP & Optimal enzyme pH & protein ppt. (zwitterion)
Sucrose consumption dec. pH (Stephan curve)

Question 6

What is the role of potassium ions in saliva?

Answer 6

Added to secretion throughout the duct (counter ion = phosphate)
Decreases a little with flow rate, remains fairly constant

Question 7

What is the role of phosphate ions in saliva?

Answer 7

As flow increase phosphate ions decrease
Phosphate ions are added to the secretion in striated so faster transit time means less phosphate released into secretion
Important in the maintenance of ionic product of HAP

Question 8

What is the role of fluoride ions in saliva?

Answer 8

Found in very low amounts in saliva (0.001-0.005 mM) found more in carious regions
Increases stability of HAP by replacing OH
Facilitates HAP precipitation

Question 9

What is the role of hydroxyapatite in saliva?

Answer 9

Ca10(PO4)6(OH)2
If conc. Of calcium & phosphate > ionic product = spontaneous Ppt.
If conc. Of calcium & phosphate < ionic product = dissolution of HAP
This means as pH inc less phosphate therefore Ionic product not exceeded leads to Dissolution.