Abstract: PURPOSE: This meta-analysis was undertaken to evaluate the efficacy of photodynamic therapy (PDT) in combination with non-surgical therapy compared to non-surgical therapy alone for patients with peri-implantitis. Methods: Bibliographic databases including Cochrane Library, PubMed, EMbase, Web of Science, CNKI, VIP, Wanfang Data and CBM were searched from inception to April 1st 2018 , to collect randomized controlled trials (RCTs) of photodynamic therapy in combination with non-surgical therapy and non-surgical therapy alone for peri-implantitis. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data, and assessed the quality. Then after cross-checking, meta analyses was performed by using RevMan 5.3 software. Meta analysis of probing depth (PD), bleeding on probing(BOP) and clinical attachment level(CAL) was conducted using weighted mean differences (WMD) for continuous data with 95% confidence intervals(CI). Results: Six studies met the inclusion criteria. Meta analysis results showed that compared to non-surgical therapy alone, PDT in combination with non-surgical therapy showed significant differences in PD(WMD=-0.81,95%CI -1.52 to -0.11, P=0.02), BOP(WMD=-5.15, 95%CI -6.29 to -4.01, P<0.00001), but no significant differences in CAL(WMD=-1.13, 95%CI -3.51 to 1.25, P=0.35). Conclusions: In the treatment of peri-implantitis, compared to non-surgical therapy alone, non-surgical therapy with PDT was more effective in reduction of probing depth and probing bleeding, but it did not significantly improve clinical attachment level. For the quantity and quality limitation of the included studies, the conclusion has to be further proved by performing more well-designed and high quality RCTs.

Key words: Photodynamic therapy, Peri-implantitis, Non-surgical therapy, Meta-analysis