Comparative Evaluation of Riboflavin and Methylene Blue Mediated Photodynamic Therapy on Periodontal Parameters in Orthodontic Patients: A Split‑Mouth Randomized Controlled Trial

Aim This study aimed to evaluate the antimicrobial effectiveness of riboflavin-mediated photodynamic therapy (PDT) on periodontal health in patients undergoing fixed orthodontic treatment and to compare its effects with methylene blue-mediated PDT.Methods A split‑mouth randomized clinical trial was conducted on ۴۰ patients undergoing fixed orthodontic therapy, comprising a total of ۱۶۰ quadrants. The quadrants were randomly allocated into four groups: riboflavin PDT (RB), methylene blue PDT (MB), control for riboflavin (CR), and control for methylene blue (CM). Photodynamic therapy was applied in the RB and MB groups at baseline and on days ۷, ۱۴, and ۲۱. Clinical periodontal parameters—including plaque index (PI), gingival index (GI), probing depth (PD), and bleeding on probing (BOP)—as well as microbial colony‑forming units (CFU) were recorded at baseline and after ۲۸ days. Statistical analysis included paired t‑tests and Wilcoxon signed‑rank tests for intragroup comparisons, and ANOVA with Tukey post hoc tests, along with Kruskal‑Wallis and Mann‑Whitney U tests for intergroup comparisons. The significance level was set at P < ۰.۰۵.Results All enrolled patients completed the study with no loss to follow-up. Both experimental groups showed significant reductions in PI, GI, PD, BOP, and microbial CFU from baseline to follow-up (P<۰.۰۰۱), with the MB group demonstrating greater improvements than the RB group. Control groups showed no significant changes in most parameters except for a slight reduction in BOP. Intergroup comparisons revealed no baseline differences (P=۰.۸۳۳), while at follow-up significant differences were observed among groups for PI, GI, BOP, and CFU (P<۰.۰۵). Additionally, PD was significantly lower in the MB group compared with both control groups (P<۰.۰۰۱). Reliability analysis showed excellent agreement for PI, GI, and BOP (ICC>۰.۹۰) and good agreement for PD and CFU (ICC>۰.۷۵).Conclusion Although methylene blue PDT showed superior outcomes, riboflavin PDT also significantly improved periodontal health and reduced microbial load in orthodontic patients. Considering its effectiveness and the advantage of not requiring specialized laser equipment, riboflavin PDT may serve as a practical alternative for clinical use, particularly in settings with limited resources.

کلیدواژه ها:

Methylene blue ، Orthodontics ، Periodontal health ، Photodynamic therapy ، Riboflavin