Comparative Study between Sodium Hexametaphosphate and Chlorhexidine Mouthwashes on Dental Plaque in Young Age, Clinical Randomized Study

Background: Chlorhexidine (CHX) and sodium hexametaphosphate (SHMP) are commonly used antiplaque agents, yet their comparative efficacy and safety profiles remain under investigation. Objective: To compare the clinical effectiveness and adverse effect profiles of CHX and SHMP mouth rinses in reducing plaque and gingival indices over a 14-day period in adolescents. Patients and Methods: In this randomized controlled trial, 220 participants were assigned equally into two groups (CHX vs. SHMP). Demographic characteristics, medical histories, and baseline clinical indices were recorded. Plaque Index (PI) and Gingival Index (GI) were assessed at baseline, day 7, and day 14. Intra- and inter-group comparisons were conducted using Wilcoxon and Mann–Whitney U tests. Multivariate linear regression identified predictors of PI change, while logistic regression assessed predictors of adverse effects. Results: There were no significant differences in baseline demographic or clinical variables between groups (p > 0.05). Both groups showed significant intra-group reductions in PI and GI from baseline to day 14 (p < 0.001). Inter-group comparison revealed that CHX produced significantly greater reductions in PI and GI at day 7 and day 14 (p < 0.01). Multivariate regression showed that treatment group (β = 0.076, p < 0.001) and baseline PI (β = 0.201, p < 0.001) were significant predictors of PI change. Adverse effects were common in both groups (Day 14: 41.8% CHX vs. 39.1% SHMP, p = 0.680), with no significant differences in frequency or type. Logistic regression showed no significant predictor of adverse events at day 14 (p > 0.05 for all variables). Conclusion: Both CHX and SHMP effectively reduced plaque and gingival inflammation over 14 days, with CHX showing superior clinical performance. However, both agents were associated with a comparable frequency and type of mild adverse effects, suggesting similar tolerability profiles.