Abstract:

  Background and Aim: The production and consumption of probiotic products have been growing over the past few years.. Yogurt is one of the most common vehicles for probiotics. The potential of these products for reduction of salivary counts of streptococcus mutans has been the subject of many studies in recent years.

  The aim of this study was to investigate the effect of a probiotic yogurt in comparison with ordinary yogurt on the salivary counts of Streptococcus mutans.

  Materials and Methods : This study was conducted as a "clinical trial Double-blind randomized crossover", in which 30 healthy dental students were participated. The salivary counts of streptococcus mutans were determined in participants by using the mitis salivarius agar environment at the start, following the three interventions ( probiotic yogurt, ordinary yogurt and non of them), and after wash out periods. The data were analyzed in terms of quality and quantity respectively by sign and kruskal wallis statistical tests.

  Results : There was a statistically significant reduction in the level of salivary streptococcus mutans counts, following 3 weeks of intervention by probiotic yogurt consumption (p< 0.01). Regular plain yogurt consumption for 3 weeks resulted in a statistically significant increase in the level of salivary streptococcus mutans counts (p< 0.01). No significant alterations of the salivary streptococcus mutans counts were observed in the third group which didn’t have any intervention during this period (p<0.9).

  Conclusion: Consumption of probiotic yogurt will result in reduction of the salivary streptococcus mutans counts which is maintained for a period of two weeks.