The Comparison of Caries-risk identification in an adolescent group by buffer capacity of saliva and salivary pH.

Abstract

Since salivary factors show a relationship to caries incidenc, this study was proposed to identify a caries-risk group by buffer capacity of saliva and salivary pH. Subjects were 13-15 year-old students in a Bangkok Metropolis secondary school. All subjects (157 males and 170 females) were healthy and had no clinical sign of salivary gland abnormality. The DMFT were recorded. After rinsing the mouth with water and chewing a piece of parafilm, stimulated saliva was collected for 5 minutes. Salivary pH was measured by a pH meter and the buffer capacity was determined by titration with hydrochloric acid. Data were analyzed by a simple correlation, F-test and LSD at 95% confidence limit. The results showed that buffer capacity significantly related with DMFT p < 0.05 with the correlation coefficient (r) = -0.255 but the salivary pH had no significant relationship (r = -0.045). When the buffer capacity of saliva were divided into low, medium and high capacity group, it was found that the DMFT of these 3 groups (2.84, 2.78 and 1.58 respectively) were significantly different p < 0.05. When the salivary pH were divided into low, medium and high pH group, it was found that the DMFT of these 3 groups (2.45, 2.21 and 2.13 respectively) showed no statistical difference. On the basis of these data, it was summarized that buffer capacity of saliva clearly identified a cariesrisk group but salivary pH showed no advantage.