The adjunctive effect of photodynamic therapy for residual pockets in single-rooted teeth: a randomized controlled clinical trial

Residual pockets are challenging sites that require additional periodontal therapy. The aim of this study was to evaluate the effect of a single photodynamic therapy (PDT) as an adjunct to scaling and root planning (SRP) in residual pockets in single-rooted teeth. A blind, split-mouth, randomized controlled clinical trial was conducted in systemically healthy subjects presenting at least two residual pockets (probing pocket depth (PPD) ≥5 mm with bleeding on probing (BoP)) in single root teeth in supportive periodontal therapy. The selected sites were assigned to receive (1) PDT + SRP or (2) SRP. In sites treated by PDT as adjunctive to SRP, the laser system included a handheld battery-operated diode laser with a wavelength of 660 nm, a power output of 60 mW, and energy density of 129 J/cm², together with methylene blue as a photosensitizer (10 mg/ml). Clinical parameters were assessed at baseline and 3 months post-therapies. Clinical parameters improved significantly after both therapies (p < 0.05), whereas higher probing pocket depth reduction and clinical attachment level gain were observed in the PDT + SRP group at 3 months (p < 0.05). In addition, sites treated by the combined approach yielded a significant reduction in the number of sites with PPD <5 mm without BoP after 3 months compared to sites treated by conventional SRP alone (p < 0.05). PDT as an adjunctive to mechanical debridement demonstrated additional clinical benefits for residual pockets in single-rooted teeth and may be an alternative therapeutic strategy in supportive periodontal maintenance.