The Effect of Cotinus coggygria Mouthwash on Halitosis and Oral Hygiene in Orthodontic Patients: A Randomized Clinical Trial.

Background/Objectives: This study evaluated the effectiveness of Cotinus coggygria (Smoke Tree) Flower Water mouthwash in reducing halitosis and improving oral hygiene parameters among adolescents undergoing fixed orthodontic treatment. Methods: A double-blind, randomized, placebo-controlled, parallel-group clinical trial was conducted with 30 individuals undergoing treatment with fixed orthodontic appliances. Participants were allocated (1:1) into two groups: Group A received the Cotinus coggygria mouthwash, while Group B received the placebo mouthwash. Hydrogen sulfide (H2S) concentration in breath, measured by the OralChromaTM II device, was the primary outcome. Secondary outcomes included dimethyl sulfide [(CH3)2S] and methyl mercaptan (CH3SH) levels, assessed with the same device, and oral hygiene status evaluated using the Modified Silness & Löe Plaque (PI-M) as well as the Silness & Löe Gingival (GI) indices. Normality of the data distribution was assessed using the Shapiro-Wilk test. Statistical analyses were conducted using the Mann-Whitney U test and Student's t-test. Results: A statistically significant reduction in H2S levels was observed in the C. coggygria group compared to placebo (p = 0.014). Median H2S levels decreased from 147.00 ppb at baseline (T0) to 35.00 ppb at follow-up (T1) after 2 weeks. A statistically significant reduction in total VSC levels was also observed in the C. coggygria group compared to placebo (p < 0.001). Median total VSC levels decreased from 254.00 ppb at baseline (T0) to 105.00 ppb at follow-up (T1) after 2 weeks. No significant differences were found between groups for the other volatile sulfur compounds. A Significant improvements were noted in periodontal parameters in favor of the C. coggygria group. The Gingival Index decreased from 2.0 to 1.3 (p < 0.001; 95% CI: -0.7 to -0.2), and the Plaque Index (PI-M) decreased from 1.6 to 1.0 (p = 0.001; 95% CI: -0.7 to -0.3). Conclusions: Cotinus coggygria mouthwash appeared to be an effective adjunct for managing halitosis and improving oral hygiene parameters in adolescents undergoing fixed orthodontic treatment. No adverse effects were reported.