Abstract
Purpose: The purpose of the present study was to examine the relationship between the pH values of dental plaque adhering to well fitting and poorly fitting prostheses and to discuss the risk of caries for teeth in different locations in the mouth.
Materials and Methods: In experiment 1, the pH values of plaque on contralateral teeth in the same arch were measured among subjects having natural dentition with no restoration. A CariostatTM was used to measure the pH values of the dental plaque. Contralateral teeth in the same arch were compared using the Wilcoxon test at a significance level of 5%. In experiment 2, the pH values of dental plaque adhering to prostheses with good or poor marginal fit were compared. The teeth evaluated included contralateral molars with fixed prostheses in the same arch. They were divided into two groups, i.e., good and poor marginal fit. The pH values of the dental plaque were measured using the same method as in experiment 1.
Results: The results of experiment 1 indicated that there was no difference in the pH values of the dental plaque between the left and right teeth in subjects having natural teeth with no restoration. In contrast, the pH values of the dental plaque in experiment 2 from prostheses with poor marginal fit were significantly lower than those of the prostheses with good marginal fit.
Conclusion: In this study, the pH values of dental plaque were compared among prostheses with different marginal fit. The results showed that the pH of dental plaque adhering to prostheses with poor marginal fit was lower and suggested that prostheses with poor marginal fit presented a higher risk for caries.
