Effects of Polyols on Streptococcus mutans and Lactobacilli

The bacteriostatic effect of xylitol on Streptococcus mutans has been documented in several long-term clinical trials. Objective: This study aimed to measure the effect of polyols products: xylitol lozenges, xylitol gum and sorbitol gum on Str. mutans, Lactobacilli, and on the stimulated salivary flow rate.Methods: Altogether 19 young adult completed the study, which included the use of xylitol lozenges (1 package/2 days), xylitol gum (5 times a day, 2 days) and sorbitol gum (as xylitol gum). Str. mutans and Lactobacilli were measured by CTR bacteria (Ivoclar Vivadent®) at the baseline and in the afternoon of the second intervention day. Stimulated salivary flow rate was also measured at the baseline and after the three interventions. Cross-over design was used by dividing the subjects into three groups with different sequence of the interventions. Results: The mean Str. mutans scores were 2.9 (SE=0.21) at the baseline, 2.5 (0.25) after xylitol lozenges, 2.7 (0.24) after xylitol gum, and 2.7 (0.23) after sorbitol gum. The mean Lactobacilli scores were 3.0 (0.29), 2.4 (0.34), 2.1 (0.29), and 2.3 (0.32), respectively. The stimulated salivary flow rates were: 7.8 ml/5min (0.96) at the baseline, 8.5 (0.98) after xylitol lozenges, 6.7 (1.00) after xylitol gum, 7.5 (0.86) after sorbitol gum. There were some individual inconsistencies, but 67% of the Str. mutans scores declined after xylitol lozenges, 56% after xylitol gum and 50% after sorbitol gum. Conclusions: Small but consistent decreases in the mean scores of Str. mutans and Lactobacilli were found after all the three two days interventions. The stimulated salivary flow rates increased after xylitol lozenges, but decreased after xylitol and sorbitol chewing gum use. Acknowledgement: This elective study project was supervised by Dr. Eino Honkala.