Effect of antimicrobial photodynamic therapy on the treatment of peri-implantitis: narrative review

Background and Objective: The greatest challenge of implantology is the maintenance of dental implants, with peri-implantitis being the main cause of implant loss. Studies highlight the importance of dental biofilm control, reduction of the inflammatory process in the peri-im plant mucosa and decontamination of the implant surface, as well as the need for surgical intervention. Recently, low-level laser therapy (LLLT) has been introduced in different dental specialties, especially those related to oral mucosa lesions and the treatment of periodontal disease. The combination of LLLT and a photosensitizer dye promotes antimicrobial activity (aPDT) and may be used as a noninvasive treatment of peri-implantitis. The objective of this study was to conduct a literature review on the use of antimicrobial photodynamic therapy (aPDT) in the treatment of peri-implantitis. Methods: The search was carried out in the PubMed, using the keywords: "Peri-implantitis", "low-level laser therapy", "antimicrobial photodynamic therapy". The inclusion criteria were: original articles and systematic reviews published until April 12, 2021, in English, that discussed use of aPDT in the treatment of peri-implantitis. Key Content and Findings: aPDT is the combination of LLLT with a photosensitizer dye, being a noninvasive technique used as an adjunct to surgical periodontal treatment. aPDT can improve the response of bone and soft tissues, reducing inflammation and painful symptoms. And this technique can be the treatment of choice for patients who do not want to be submitted to conventional surgical treatment or for patients with systemic conditions that contraindicate surgical management. Conclusions: aPDT can be considered an adjunct to mechanical (scaling) and surgical (grafts) treatments in peri-implantitis since it appears to be effective in reducing the bacterial load and has potential as therapy. Additionally, clinical and radiographic follow-up of the patient is important to monitor the improvement of gingival inflammation, implant mobility, and the interruption of bone loss.