Analysis of Correlation between Caries Risk Factors to Establish an Effective Clinical Testing and Diagnostic System for Caries Risk

Abstract

Previous studies investigating caries risk have often analyzed either salivary buffering capacity or individual bacteriological risk factors. However, individuals differ in risk levels for respective factors. Furthermore, many studies have involved the use of simple test kits, while few studies have additively integrated multiple risk factors into their analysis. Therefore, correlations among individual factor levels could be important in investigating caries risk. This study investigates the correlation between an individual's respective caries risk factor levels in order to establish a more effective clinical testing/diagnostic system of caries risk, and analyzes the correlation among the following caries risk factors in 59 adult subjects : buffering capacities of saliva at rest and with mastication by the buffer pH method ; and the presence of S. mutans and S. sobrinus in saliva by cultivation. There were significant correlations between salivary buffering capacity values at rest and with mastication (r=0.48, p<0.001). Significant correlations were also observed between the numbers of S. mutans and S. sobrinus in subjects with both S. mutans and S. sobrinus (r=0.69, p<0.05). There were no significant differences between the proportions of subjects with S. sobrinus in the high and low S. mutans number groups, and there were no significant correlations between salivary buffering capacity and the number of S. mutans. In this study, no significant correlations were observed between salivary buffering capacity as a protective factor and cariogenic bacteria as an offensive factor. This suggests that a comprehensive analysis of a combination of both factors may be important in identifying their relationship with caries development.