Comparative Efficacy of Chlorhexidine and Sodium Bicarbonate Dentifrices in Plaque and Gingival Inflammation Reduction: A Randomized Controlled Trial

Objective: To compare the efficacy and tolerability of chlorhexidine versus sodium bicarbonate dentifrices for reducing plaque and gingival inflammation over 6 weeks in orthodontic patients. Methods: In this randomized, double-blind, parallel-group trial, 120 participants were allocated 1:1 to chlorhexidine or sodium bicarbonate dentifrice. Participants brushed twice daily for 6 weeks using standardized toothbrushes and the Charters’ technique. Plaque Index (PI), Gingival Index (GI), and Bleeding on Probing (BOP) were assessed at baseline and 6 weeks. Adverse events and adherence were recorded. A linear mixed-effects model assessed group, time, and group×time effects; results are presented with p-values. Results: Both groups showed significant improvements from baseline. Compared with sodium bicarbonate, chlorhexidine produced greater reductions in PI (≈42.9% vs. 30.0%), GI (≈44.4% vs. 23.5%), and BOP (≈59.8% vs. 39.3%) (all p<0.05). Taste alteration and tooth staining occurred more frequently with chlorhexidine. Subgroup analyses indicated attenuated improvements among smokers compared with non-smokers. Conclusion: Over 6 weeks, chlorhexidine dentifrice demonstrated superior antiplaque and anti-gingivitis efficacy but with more adverse effects, whereas sodium bicarbonate offered fewer side effects and moderate efficacy. Smoking status negatively impacted outcomes in both groups. Long-term studies are warranted to evaluate sustained benefits and tolerability.