Whole Saliva pH and Dental Needs

Objectives: Salivary pH ranges from 6.2 to 7.6 and is kept near neutrality. We are interested in this variation and hypothesized people with certain pH values may show more extensive dental treatment needs.
Methods: Clinical data and saliva samples were obtained from the University of Pittsburgh Dental Registry and DNA Repository project. A total of 189 patients were assessed for their saliva pH values. pH was determined by the use of commercial strips. Since some patients required stimulation to provide a saliva sample, having had stimulation was considered in the analysis. Stimulation was done by the use of gum or candy to stimulate salivary secretion. Sex and ethnicity were also considered. A diagnosis of periodontitis and presence of dental restorations were the outcomes measured. Subjects were divided in two groups based on the pH of their saliva (above or below the mean of all subjects). Chi-square or Fisher’s exact and t tests were used in all comparisons with an alpha of 0.05.
Results: Out of the 189 subjects, 95 patients provided a saliva sample without the need for stimulation, 97 subjects were females, and 23 were African descendants. The mean pH of the saliva in all study participants was 7.16. The mean pH of saliva among the subjects that were stimulated was 7.23 and for the ones that did not need stimulation was 7.08. When all subjects were included in the comparison, there was no difference regarding having periodontitis or dental restorations among the individuals with saliva pH above or below the mean value of the cohort. However, Whites with restorations were more likely to have a saliva pH above the mean of the cohort (p= 0.038), whereas Blacks with restorations appeared to be less likely to have saliva pH above the mean of the cohort (p=0.059). Whites that had dental restorations and saliva pH above the mean of the cohort had a slightly higher saliva pH mean than Blacks that had dental restorations and saliva pH above the mean of the cohort (Blacks mean saliva pH was 7.415 and Whites mean saliva pH was 7.516, p=0.06).
Conclusions: These data suggest that variation in saliva pH alone does not explain the differences in distribution of dental restorations between Blacks and Whites with saliva pH above the mean of the studied cohort.