Abstract: PURPOSE: To evaluate the clinical benefits of Er:YAG laser combined with guided bone regeneration (GBR) in the treatment of peri-implantitis-assocaited osseous defects. METHODS: Twenty-six patients (34 implants in total) who underwent implant restoration in Dental Disease Prevention and Treatment Institute, Jiading District, from 2017 to 2019 and were diagnosed with peri-implantitis with osseous defects, and randomly divided into the experimental group and control group. The two groups of patients received open flap surgery, debridement and GBR treatment. The only difference in the experimental group was the use of Er: YAG laser to modulate and remove inflammatory tissue as well as to decontaminate the implant surface, instead of traditional mechanical treatment in the control group. The probing depth (PD), bleeding on probing (BOP), and plaque index (PI), the height of the bone defect around the implant (reduce of marginal bone level, RBL) were recorded and compared. SPSS 20.0 software package was used to analyze the data. RESULTS: The PD, BOP, PI and RBL of the two groups of patients were significantly improved after treatment with different methods. There was no significant difference in the improvement of PD, BOP and PI between the two groups 6, 12 and 24 months after treatment, while the improvement of RBL in the experimental group was significantly better than that of the control group 12 and 24 months after treatment. CONCLUSIONS: In the treatment of GBR with peri-implantitis and osseous defects, Er: YAG laser therapy is more effective than traditional mechanical methods, and is more conducive to the regeneration of new bone.

Key words: Er:YAG laser, Peri-implantitis, Guided bone regeneration(GBR), Osseous defects