Evaluation of the therapeutic effect of repeated photodynamic therapy-assisted SRP treatments on class II furcation

Objective

This study aims to evaluate whether repeated photodynamic therapy (PDT) ad-junctive to periodontal scaling and root planing (SRP) provides additional short-term clinical benefits for teeth with class II furcation involvement (FI).

Materials and methods

This single-center randomized controlled trial enrolled 27 patients (85 Class II FI sites), randomly allocated to receive either scaling and root planing (SRP) with adjunctive photodynamic therapy (PDT) at baseline, 1, and 2 weeks (Group A) or SRP alone (Group B). Each photodynamic therapy session involved injecting 0.1 mg/mL methylene blue as a photosensitizer into the periodontal pocket, followed by irradiation with a 660±10 nm wavelength laser at a power of 160-220 mW for 60 s. Clinical outcomes (bleeding on probing [BOP %], probing depth [PD], clinical attachment loss [CAL]) and gingival crevicular fluid (GCF) biomarkers (IL-4, IL-6) were assessed. Subgingival microbiota was analyzed via 16S rRNA sequencing, while patient-reported outcomes (PROs) included Visual Analog Scale (VAS) and oral health impact (OHIP-14).

Results

At the 3-month follow-up, Group A demonstrated significantly lower BOP % (33.33 % vs. 55.81 %; p<0.05) and PD reduction (1.26±0.62 mm vs. 0.95±0.65 mm; p<0.05) compared to Group B. However, no significant intergroup differences were observed in CAL (p>0.05). Analysis of GCF revealed a significant time × group interaction in cytokine expression (p<0.001), with Group A showing more favorable inflammatory modulation. Microbiological assessment indicated a marked reduction in periodontal pathogens and improved microbial diversity in Group A (p<0.05). Patient-reported outcomes (PROs) demonstrated comparable therapeutic pain perception and postoperative fatigue between groups (VAS: p>0.05). However, Group A showed significantly better oral health-related quality of life, as evidenced by lower OHIP-14 total scores (15.88±5.19) compared to Group B (18.12±5.09; p<0.05).

Conclusions

Repeated PDT-assisted SRP enhances short-term soft tissue healing in Class II FI sites, modulates inflammation-related cytokines and subgingival microbiota, and reduces psychological discomfort without prolonging perceived treatment pain, duration or fatigue.