SummaryIntroductionChlorhexidine is considered the most potent chemotherapeutic agent against Streptococcus mutans. However, its side effects due to prolonged use, indicates need for alternatives. The study intended to assess and compare antimicrobial efficacies of probiotic, xylitol and chlorhexidine mouth rinses in children and elderly.MethodsThe study was a Double blind Randomized Controlled Trial conducted among residential school children aged 5-12 years and elderly greater than 60 years residing in old age homes. (ClinicalTrials.gov ID: NCT04399161). 30 participants each among children and elderly were chosen based on eligibility criterion (high risk for caries). They were further randomly divided into 3 groups with 10 participants in each group. Participants were asked to rinse with 15 ml of freshly prepared mouth rinses once daily for 2 minutes for 14 days. Antimicrobial efficacy was determined by assessing change in Streptococcus mutans levels in dental plaque.ResultsSignificant reduction in Streptococcus mutans counts were observed in both children and elderly (Chlorhexidine: mean difference = 3.11 log10CFU/g, p = 0.022, Xylitol: mean difference = 0.93 log10CFU/g, p = 0.046, Probiotic: mean difference = 1.91 log10CFU/g, p = 0.023 in children); (Chlorhexidine: mean difference = 2.23 log10CFU/g, p = 0.004, Xylitol: mean difference = 1.39 log10CFU/g, p = 0.009, Probiotic: mean difference = 1.61 log10CFU/g, p = 0.018 in elderly). Intergroup comparison showed no significant difference.ConclusionsAntimicrobial efficacy of xylitol and probiotic mouth rinses were comparable to that of chlorhexidine in both children and elderly. Probiotics could potentially be more efficacious than xylitol among children.