Antimicrobial photodynamic therapy effects mediated by methylene blue in surfactant medium as an adjuvant treatment of teeth with apical periodontitis and presence of fistula-Protocol for randomized, controlled, double-blind clinical trial.

Objective: This study aims to evaluate the efficacy of photodynamic therapy as an adjunct to conventional endodontic treatment in patients with apical periodontitis and fistulas. In this study, a fistula is characterized as a pathological conduit originating from the infected region at the root apex of the tooth, traversing the oral mucosa, and extending to the external surface of the gingiva. This pathological condition frequently complicates the management of endodontic infections, thereby necessitating the evaluation of supplementary therapeutic interventions. The standard treatment for endodontic infections involves thorough disinfection of the root canal system to remove microbial contamination from the canal and surrounding tissues. To potentially augment the efficacy of conventional treatment, aPDT is proposed as a supplementary, non-invasive technique. This innovative technique uses a photosensitizer, which is a light-sensitive dye, in combination with a light source to produce reactive oxygen species. Reactive oxygen species can effectively target and eliminate bacteria in the root canal system, potentially enhancing treatment outcomes.

Methods: The study will involve 140 teeth with apical periodontitis and fistulas. The teeth will be randomly assigned to one of two treatment groups. Group I will receive only the conventional endodontic treatment, which includes root canal cleaning, shaping, and obturation. Group II will undergo the same conventional endodontic treatment, but with an additional step of aPDT. The aPDT procedure involves applying a photosensitizer to the root canal and irradiating it with light to produce reactive oxygen species. Each group will consist of 70 teeth to ensure adequate statistical power. The primary outcome is fistula resolution, assessed clinically at 15 and 30 days post-treatment. The secondary outcome is the comparison of apical radiolucency from periapical radiographs to evaluate healing and reduction of periapical pathology.

Conclusions: The study aims to determine if adding aPDT significantly improves the management of apical periodontitis and overall success rates of endodontic treatment. The results will provide insights into the effectiveness of aPDT as an adjunctive treatment and its potential benefits in clinical practice.