Erosive Assessment of Dry-Mouth Tablets and Lozenges on Teeth Substrates

Objectives: To measure the pH values, titratable acidity, and potential erosive effect by gravimetric analysis of commercially available dry mouth lozenges/tablets and their effect on enamel and dentin.
Methods: Eleven different commercially available Lozenges and tablets were used to assess the pH analysis and titrable acidity. The pH recording was repeated five times, from five different tablets/lozenges each of the same product. Titrable acidity was measured using pH meter and pH indicator (phenol red). The gravimetric analysis was performed by submerging human enamel and dentin blocks in 5 ml of each of the tablet solution for a total of 2 weeks, with gravimetric measurements made at baseline, 24 hours, 48 hours, 96 hours, 1 week, and 15 days. The erosive potential was descriptively analyzed, and a Spearman correlation coefficient was used to assess the relationship between the erosive potential and the pH values.
Results: Shapiro Wilk test was performed as well as a histogram analysis. All data (pH, TA and enamel and dentin loss) presented non-normal distribution and therefore non-parametric tests were used (Spearman correlation, Kruskal- Wallis and Mann-Whitney).
A significant correlation between pH and TA was observed for this dataset (p<0.0001; Spearman correlation). Both variables (pH and TA) were strongly correlated with dentin loss. For the pH, the Rho Spearman correlation coefficient value was -0.68, which indicates a strong negative correlation (p<0.0001, Spearman correlation). For TA, the Rho Spearman correlation coefficient value was -0.71, which indicates a strong negative correlation (p<0.0001, Spearman correlation)
Conclusions: There is a large variation in the pH values of commonly used Lozenges and tablets, and there is a strong correlation between pH values, titratable acidity and erosive potential of commonly used lozenges which are used to treat xerostomia.