Effect of the technique of photodynamic therapy against the main microorganisms responsible for periodontitis: A systematic review of in-vitro studies

Objective: The present study aimed to conduct a systematic review of the literature, to evaluate, in vitro, the effectiveness of the technique of photodynamic therapy against microorganisms associated with periodontal disease. Design: This systematic review was carried out in accordance with the items on the PRISMA checklist and Cochrane guidelines. Only in vitro studies that evaluated the effect of the technique of antimicrobial photodynamic therapy on periodontopathogenic microorganisms were included. Results: A total of 32 articles published between 2000 and 2021 were included for qualitative analysis. For microorganisms in suspension, 25 studies (78.12%) showed a reduction greater than or equal to 3 logs CFU/mL of species associated with periodontal disease. In biofilms, three studies (42.7%) showed a reduction greater than or equal to 3 logs CFU/mL. Conclusions: The results showed that the technique of photodynamic therapy may be a promising alternative to conventional antimicrobial approaches for reducing bacteria closely associated with periodontal disease. Some parameters (pre-irradiation time, type of photosensitizer, standardization of light parameters) need to be better established before conducting clinical studies.