VARIATIONS IN THE pH OF SALIVA OF FIVE INDIVIDUALS

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

The mean pH of saliva tested 276 times in 5 adults was 6.72 0.015, which was similar to other published reports. This reading was obtained by using the glass electrode.

An analysis of variance indicated that each individual's average pH of saliva was significantly variable from one another.

Of these averages 2 were significantly more acid than the average 6.72, 2 were not significantly different from the average and one was significantly less acid than the average.

Two hundred fifty-two determinations of the pH of saliva from 5 individuals were analyzed statistically for variations during the day. The readings were taken at 9 and 11 A.M., and at 1, 3 and 5 P.M.

The group of subjects was significantly at variance during the day.

The group of subjects was significantly different from the daily mean at 9 A.M. and probably at 5 P.M., but not at the other periods.

No subject was significantly at variance during the day.

Subjects were significantly at variance with one another at 9 A.M. and probably at 11 A.M., but thereafter were not. That is, as the day progressed individual identities of saliva were lost and tended toward homogeneity.

Subjects did not deviate significantly (1 exception) from their respective individual daily means for each of the 5 periods of time.

Subjects did not deviate significantly (1 exception) from their respective bihourly means for each of the 5 periods of time.