effects of three mastic gums on the number of mutans streptococci, lactobacilli and ph of the saliva.

in the recent years, herbal oral hygiene products have gained increasing attention. the aim of this study was to assess the effects of three types of mastic gums on the level of mutans streptococci, lactobacilli and ph of the saliva.forty-two students in the age range of 20-30 years were divided into three parallel groups; each of them separately used pure mastic gum, xylitol mastic gum and probiotic mastic gum for three weeks. number of microorganisms and ph of the saliva were assessed before and after the intervention. the data were analyzed using wilcoxon signed rank, paired-sample-t, kruskal-wallis and tukey's post-hoc tests and oneway anova.level of mutans streptococci showed a significant reduction compared to its baseline value in all three groups (p<0001 for all). salivary lactobacillus count increased in the groups using pure and xylitol mastic gums but decreased in the group using probiotic type, albeit these changes were only significant in the group using probiotic mastic gum (p<0.001). use of pure and xylitol mastic gums increased the ph of the saliva but not significantly. in the group using probiotic mastic gum, the ph of the saliva decreased significantly (p=0.029).three weeks use of all mastic gums resulted in a significant drop in the number of mutans streptococci in the saliva. however, the drop in the saliva ph due to the use of probiotic mastic gum is not in favor of dental health.