STUDIES ON THE pH OF SALIVA

¹ Research Laboratory, School of Dentistry, University of Kansas City, Kansas City, Mo.

(1) The mean pH of saliva of 7 subjects was 6.64 0.006, which was based upon 1552 electrometric tests made with the glass electrode at regular bi-hourly intervals for an entire year. The statistical analysis of variance aided in interpreting the results.

(2) The pH of saliva for the group varied markedly during the year and indicated seasonal fluctuations.

(3) The subjects were significantly variable for each month and for the year, although each one tended to follow the general trend of the group.

(4) Each subject displayed individualistic salivary pH characteristics.

(5) The pH of saliva of the group was lowest at 9 A.M., was always greater at 11 A.M., passed through the annual mean at 1 P.M. and was highest at 5 P.M.

(6) The pH of saliva for the group was significantly variable from month to month at each bi-hourly period.

(7) The pH of saliva was compared at the 5 bi-hourly periods for each month. The variability was significant only in May, June, July, and October.

(8) The subjects varied markedly (in salivary pH) from one another at each bi-hourly period.

(9) Each subject tested throughout the year had saliva which varied significantly in pH during the day at bi-hourly intervals.