Effect of a mouthrinse containing rice peptide CL(14-25) on early dental plaque regrowth: a randomized crossover pilot study

BACKGROUND: We aimed to evaluate clinically the effect of mouthrinse containing a rice peptide on early dental plaque regrowth. METHODS: The study was designed as a double-masked, two-group crossover randomized pilot trial, involving 10 periodontally healthy volunteers. After receiving a professional tooth cleaning at baseline, over the next 3 days each participant refrained from all oral hygiene measures and had two daily rinses with 20 ml of the test mouthrinse containing 0.4 % rice peptide CL(14-25) or placebo rinse. At the end of each experimental period, plaque score was assessed using the modified Volpe’s method, and the participants filled out a questionnaire. Each participant underwent a 7-day washout period followed by a second allocation. The plaque score was the primary outcome of the study and participant perception was the secondary outcome. RESULTS: No adverse effects were observed in the participants during the study. Clinically, the mean plaque score of the examined teeth was significantly lower in the test group (2.44 ± 0.74, CI: 1.91–2.96) than the placebo group (2.65 ± 0.63, CI: 2.20–3.10) (P < 0.05). When analyzed according to the type of teeth, a significantly lower score of the premolars/molars was observed in the test group (2.39 ± 0.68, CI: 2.08–2.71) than that in the placebo group (2.66 ± 0.58, CI: 2.39–2.93) (P < 0.05). CONCLUSIONS: The mouthrinse containing 0.4 % rice peptide CL(14-25) was effective in reducing the early regrowth of dental plaque. However, clinical relevance of this efficacy needs to be validated in a future large-scale study. Trial registration: UMIN Clinical Trials Registry (UMIN-CTR) R000014000. Date of formal registration: November 1, 2013.