Comparative study between the effects of photodynamic therapy and conventional therapy on microbial reduction in ligature-induced peri-implantitis in dogs.

BACKGROUND: Progressive peri-implant bone losses, which are accompanied by inflammatory lesions in the soft tissues, are referred to as peri-implantitis. The aim of this study was to compare the effects of photodynamic therapy (PDT) and conventional technique on microbial reduction in ligature-induced peri-implantitis in dogs. METHODS: Eighteen third premolars from nine Labrador retriever dogs were extracted and the implants were submerged. After osseointegration, peri-implantitis was induced. After 4 months, ligature was removed and natural bacterial plaque was allowed to form for another 4 months. The animals were then randomly divided into two groups. In the conventional group, they were treated using mucoperiosteal flaps for scaling the implant surface and chlorexidine (conventional) irrigation. In the PDT group, only mucoperiosteal scaling was carried out before photodynamic therapy. Inside the peri-implant pocket, a paste-based azulene photosensitizer was placed and then a GaAlAs low-power laser (lambda=660 nm, P=40 mW, E=7.2 J for 3 minutes) was used. Microbiological samples were obtained before and immediately after treatment. Before treatment, one implant was removed and analyzed by scanning electron microscopy to validate the contamination. RESULTS: The results of this study showed that Prevotella sp., Fusobacterium sp., and S. Beta-haemolyticus were significantly reduced for both groups. After treatment, no significant differences were observed between the groups. CONCLUSION: These findings suggest that photodynamic therapy is a non-invasive method that could be used to reduce microorganisms in peri-implantitis.

O emprego da terapia fotodinâmica (PDT) na redução bacteriana em periodontia e implantodontia / Photodinamic therapy in dentistry

A terapia fotodinâmica tem sido utilizada na área da saúde para a destruição seletiva de tumores e redução microbiana. Esta terapia consiste na associação de uma fonte de luz em baixa intesidade associada a um corante. A morte microbiana ocorre quando o corante absorve a energia luminosa, levando a produzir substâncias altamente reativas, que causam danos ao microorganismo ou célula alvo. Na odontologia, sua utilização é bastante indicada, visto que a terapia fotodinâmica se mostra mais eficiente em infecções localizadas, de pouca profundidade e de microflora conhecida. Neste estudo, apresentaremos alguns casos clínicos tanto em periodontite quanto em periimplantite em que foi utilizada a terapia fotodinâmica com um alto índice de sucesso