Short-term microbiological effects of photodynamic therapy in non-surgical periodontal treatment of residual pockets: A split-mouth RCT

Background and Objective: Photodynamic therapy (PDT) has been used as a therapeutic alternative to treat periodontitis, especially in challenging sites that require additional periodontal therapy such as residual pockets. The aim of this split-mouth randomized trial was to evaluate the microbiological and clinical effects of PDT on non-surgical treatment of unresponsive pockets. Study Design/Materials and Methods: A split-mouth, randomized controlled clinical trial was conducted in 15 patients presenting at least two residual pockets (probing pocket depth [PPD] ≥5 mm with bleeding on probing [BoP]) in single-rooted teeth in supportive periodontal therapy. The selected sites randomly received: (1) SRP + PDT: scaling and root planing combined with photodynamic therapy (methylene blue as a photosensitizer), or (2) SRP: scaling and root planing alone. The concentrations of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were evaluated using a Real-time PCR technique at baseline and 3, 7, 14, and 90 days. Clinical parameters were assessed at baseline and 3 months post-therapies. Results: Both treatments promoted clinical improvements, with additional benefits to the SRP + PDT group in PPD reduction and clinical attachment level gain (P < 0.05) after 3 months. Only the SRP + PDT group exhibited a statistically significant reduction in the levels of A. actinomycetemcomitans on the 3rd and 7th days after therapy (P < 0.05), and a lower concentration of this pathogen was detected at 7 days in the SRP + PDT group when compared to the other therapy (P < 0.05). Conclusion: The combined therapeutic approach SRP + PDT may reduce A. actinomycetemcomitans levels for a short-term period, associated with additional improvement in clinical parameters in treating residual pockets. Lasers Surg. Med. 48:944–950, 2016.