Comparative Efficacy of Nigella sativa and Chlorhexidine Mouthwashes in the Management of Gingivitis: A Randomized Controlled Trial.

Objectives: This study aimed to compare the efficacy of Nigella sativa (N. sativa) mouthwash and chlorhexidine (CHX) in the management of gingivitis. Methods: This triple-blind, parallel-group randomized controlled trial (Iranian Registry of Clinical Trials, IRCT20221212056786N2) was conducted at the Department of Periodontology, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Thirty-six patients aged 20-40 years with gingivitis were randomized in a 1:1 ratio using simple randomization to receive either 20% N. sativa mouthwash or 0.2% CHX mouthwash twice daily for 14 days. Participants, outcome assessors, and statisticians were blinded. Clinical parameters, including plaque index (PI, primary outcome), bleeding index (BI), and staining index (SI), were recorded at baseline and after 14 days. Data were analyzed using analysis of covariance, with statistical significance set at p < 0.05. Results: All 36 participants completed the study. Both N. sativa and CHX mouthwashes significantly reduced PI (mean difference: N. sativa, 33.44 ± 0.72; CHX, 32.72 ± 1.37; p < 0.001 for both) and BI (mean difference: N. sativa, 19.44 ± 0.80; CHX, 19.98 ± 0.81; p < 0.001 for both) after 14 days compared with baseline. Between-group differences were not significant for PI (mean difference: -0.72; 95% confidence interval [CI]: -1.94 to 0.50; p = 0.057) or BI (mean difference: -0.54; 95% CI: -1.10 to 0.02; p = 0.053). A statistically significant but clinically trivial increase in SI was observed in the N. sativa group (mean change: 0.78 ± 1.06; p = 0.006), but not in the CHX group (mean change: 0.44 ± 1.29; p = 0.163). No adverse events, such as taste alteration or mucosal irritation, were reported based on participant self-reports. Conclusions: N. sativa mouthwash showed similar efficacy to CHX in reducing plaque and gingival inflammation over 14 days, suggesting it may be a viable alternative for short-term gingivitis management. However, its potential for slight tooth staining warrants caution, and further studies are needed to assess long-term effects.