Comparison of the antimicrobial effects of 0.2% curcumin mouthwash and chlorhexidine mouthwash on <i>Streptococcus mutans</i> in orthodontic patients: a randomized clinical trial.

The use of mouthwash is a practical approach to decreasing bacteria during orthodontic treatment. This study aimed to investigate the antibacterial effect of 0.2% curcumin mouthwash on <i>Streptococcus mutans</i> in individuals undergoing fixed orthodontic treatment. For this double-blinded clinical study, 22 orthodontic patients aged 15 years or older with no systemic or periodontal diseases were selected and randomly divided into 2 groups of 11 individuals. One group received 0.2% curcumin mouthwash (intervention), while the other group received 0.2% chlorhexidine mouthwash (control) to use twice daily. Orthodontic elastics were collected from the patients' mouth immediately before the first use of the mouthwash, immediately after the first use, and after 20 days of mouthwash use. The elastics were stored in normal saline, and the samples were transferred to a microbiology laboratory for serial dilution, plating, and incubation. After 48 hours, the number of colony-forming units (CFUs) of <i>S mutans</i> were counted and compared. The Friedman and Wilcoxon tests were used for statistical analysis of intragroup data, while the Mann-Whitney U test was used for intergroup comparisons. A difference of P < 0.05 was considered statistically significant. Both the curcumin and chlorhexidine groups demonstrated a statistically significant decrease in CFUs of <i>S mutans</i> immediately after the initial use as well as after 20 days' use (P < 0.05). After the first use, there was no statistically significant difference between the groups in the reduction of CFUs (P = 0.071). However, after 20 consecutive days of mouthwash use, the curcumin group had a significantly greater decrease in CFUs of <i>S mutans</i> than the chlorhexidine group (P < 0.001). Both chlorhexidine and curcumin mouthwashes significantly reduced the number of <i>S mutans</i> colonies when used regularly. The results of the present study suggest that curcumin herbal mouthwash is a superior choice to chlorhexidine for orthodontic patients due to its long-term antibacterial properties.