Comparing the efficacy of xylitol-containing and conventional chewing gums in reducing salivary counts of Streptococcus mutans: An in vivo study

OBJECTIVE: Dental caries is among the most common chronic diseases in humans. Streptococcus mutans is generally responsible for most cases of dental caries. The present study sought to compare the effects of xylitol-containing and conventional chewing gums on salivary levels of S. mutans. MATERIALS AND METHODS: This study adopted a crossover design. Two type of chewing gums (one containing 70% xylitol and approved by the Iranian Dental Association, and another containing sucrose) were purchased. The participants were 32 individuals aged 18–35 years whose oral hygiene was categorized as moderate or poor based on a caries risk assessment table. Salivary levels of S. mutans were measured at baseline, after the first and second phases of chewing gums, and after the washout period. The measurements were performed on blood agar and mitis salivarius-bacitracin agar (MSBA). Pairwise comparisons were then used to analyze the collected data. RESULTS: Salivary levels of S. mutans in both groups were significantly higher during the two stages of chewing gum than in the washout period or baseline. Moreover, comparisons between the two types of gums suggested that chewing xylitol-containing gums led to greater reductions in S. mutans counts. This effect was more apparent in subjects with poor oral hygiene than in those with moderate oral hygiene. CONCLUSIONS: Xylitol-containing chewing gums are more effective than conventional gums in reducing salivary levels of S. mutans in individuals with poor–moderate oral hygiene.