Terapia fotodinâmica antimicrobiana para o tratamento da periodontite

: estudo in vitro e ex vivo utilizando uma nova opção de fonte de luz

Abstract

Introduction: Periodontitis is a complex disease, with multiple etiologic factors, which develops through time, due to dental plaque accumulation and bacterial dysbiosis. Antibiotic therapy is the most used adjuvant therapy, which have demonstrated having issues related to bacterial resistance. So, antimicrobial PhotoDynamic Therapy (aPDT) has been studied as a potential substitute for antibiotic therapy, as an adjuvant therapy. In this work, it is intended to study the potential of a new approach using aPDT with protoporphyrin IX as photosensitizer and dental curing light, equipment which is available in every dental clinic, as light source. Material and methods: We have performed photoinactivation of periodontopathogens (Enterococcus faecalis bacteria and Candida albicans fungi) studies in vitro and ex vivo in teeth using porphyrins as photosensitizer and dental curing light as light source. For these studies, we have selected ProtoIX as photosensitizer (tested at 10 and 20 μM in vitro and at 20 and 50 μM) and dental curing light as light source. Results: In in vitro studies, we have observed viability decrease on C. albicans fungi and E. faecalis bacteria, above 3 log UFC/mL and 6 log UFC/mL, respectively, when exposed with a ProtoIX concentration of 20 μM and 20 minutes of dental curing light irradiation. In ex vivo studies, we have observed a slight decrease of C. albicans fungi survival (0.8 log UFC/mL), after its incubation on 20 μM of ProtoIX and 20 minutes irradiation, with a dental curing light. Conclusion: This study has shown aPDT’s high potential of periodontopathogens inactivation using ProtoIX as photosensitizer and dental curing light as light source. However, several more studies must be conducted to improve this protocol, so it can be used in clinical environments.

Date of Award	21 Jul 2022
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Anna Moura (Supervisor) & Ana Peixoto Gomes (Co-Supervisor)