Antimicrobial photodynamic therapy combined to periodontal treatment: experimental model

Abstract

tBackground: Antimicrobial photodynamic therapy (aPDT) has been used as an adjuvant treatment forperiodontitis. It combines a photosensitizer with a light source to induce reactive oxygen species and killmicrobial cells. PpNetNI is a protoporphyrin derivative, and it has a chemical binding site at biofilm andgreat affinity to microbial cells. The aim of this study was to investigate the effects of aPDT as an adjuvanttreatment for periodontitis.Methods: Thirty healthy male rats Wistar (Rattus norvegicus) were used in this study (Approved by UNI-NOVE Ethical committee AN0029/2015). Periodontitis was induced by placing a cotton ligature aroundthe first mandibular molar in a subgengival position. The contralateral mandibular first molar receivedneither a ligature nor any treatment, and was used as a control. After 7 days, the ligature was removedand all animals received scaling and root planing (SRP) and were divided according to the following treat-ments: SRP group (received SRP and irrigation with PpNetNI, 10 M) and aPDT group (PpNetNI 10 Mfollowed by LED irradiation). aPDT was performed with a LED (630 nm) with an output power of 400 mW(fluence-rate 200 mW/cm2; fluence 18 J/cm2). Rats were euthanized at 24 h, 48 h and 7 days postopera-tively. The area of bone loss in vestibular region of the first molar was evaluated by Optical CoherenceTomography (OCT, THORLABS LTD., Ely, UK). Data were analyzed statistically (ANOVA and Tukey tests,p < 0.05).Results: The animals treated by aPDT showed bone gain of approximately 30% compared to the SRP groupfollowing 7 days from the treatment.Conclusion: aPDT promoted bone recovery 7 days after periodontal intervention.