VARIATION OF CALCIUM CONCENTRATION IN THE HUMAN SALIVA

Abstract

The calcium concentrations in saliva have been investigated by large number of workers since the first report about it was presented by Rose (1908).
These reports, however, do not necessarilly show the same results because of their different experimental methods, but also considerablly a wide range of variations observed among the values obtained.
Therefore it is necessary to seek and clarify the cause for it.
Adding to this, other papers dealing with the mechanism of salivary secretion, especially the study in regard to inorganic constituents of saliva and blood serum, or the rate of salivary flow and constituents of salivary secretion were available too.
The author studied ccmparative calcium concentrations in mixed saliva and parotid saliva, relating to blood serum calcium, urinary calcium, age, daily fluctuations, water supplies and caries activity.
The results obtained are as follows:
1) The average value of calcium concentration in mixed saliva, taken from healthy male adults (from 20 to 27 years of age) was 5.81 mg/dl±1.16.
2) A slight significantcalcium correlation between calcium concentrations in mixed saliva and that in blood serum was observed.
3) No evidence that the presence of caries, dental calculation to the calcium concentrations was detected.
4) The marked variations in calcium concentrations in mixed saliva occured under some conditions, espeially dietry condition.
The average value of calcium concentrations was lower in parotid saliva (3.32 mg/dl) than in mixed saliva (15.8 mg/dl±1.16).
Any remarkable daily variations in calcium concentration could not be found in each individual.
6) With an increasing secretion of parotid saliva (during one fixed time) per time, calcium concentration was raised, and if the amount of saliva secreted was over 7-8 ml/10 min., it reached maximum.
7) Calcium concentration in parotid saliva was higher in children in adults.
8) The presence of caries, DMF rate and calcium concentration in parotid saliva, taken from under a specific condition, that is, a restricted water intake, none of those had any significant correlationship to the calcium concentration.
9) No significant correlation was observed between calcium concentrations in mixed saliva and blood serum.
However, if under the condition of restricted water intake, a significant correlation (r=0.42±0.016) was present between two of them, whereas the relation to urinary calcium was diminshed.
This indicates the occurence of the variations in salivary calcium concentration results from a very similar metabolic behaviour to that of urinary calcium, even though calcium itself was distributed from blood serum.