Abstract: PURPOSE: The aim of the present meta analysis was to systemically evaluate the scientific evidence for the effectiveness of neodymium-doped yttrium aluminium garnet(Nd:YAG) laser in combination with non-surgical periodontal therapy compared to non-surgical periodontal therapy alone for patients with periodontitis. METHODS: Electronic database searches of MEDLINE-PubMed, ISI Web of Science, Cochrane Controlled Clinical Trial Register, Cochrane Database of Systematic Reviews, China National Knowledge Infrastructure(CNKI), Wanfang Data Knowledge Service Platform, CQVIP Company Profile, and China Biology Medicine disc were performed to identify appropriate studies for clinical randomized controlled trials, as well as hand-searching of relevant journals, conference paper and thesis of master and Ph. D from the earliest records to September 30, 2015. Quality assessment was made according to Newcastle-Ottawa Quality Assessment Scale(NOS), and the datum were extracted. Then heterogeneity test and meta analysis were performed on the outcomes, and the publication biases of the outcome by meta analysis were assessed. Meta analysis of interleukin-1β(IL-1β), gingival crevicular fluid(GCF), plaque index(PI), gingival index(GI), probing depth(PD) and attachment loss(AL) were performed using weighted mean differences for continuous data with 95% confidence intervals. RESULTS: A total of 12 articles met the eligibility criteria and entered into the study. When compared to non-surgical periodontal therapy alone, Nd:YAG laser in combination with non-surgical periodontal therapy showed significant differences in GCF(I2=0.0%,P=0.000), GI(I2=0.0%,P=0.000) and PD(I2=85.8%,P=0.032) at 12 weeks post-therapy. No significant publication biases were found. CONCLUSIONS: The findings of this meta analysis suggest that use of Nd:YAG laser as an adjunctive therapy to non-surgical periodontal therapy could potentially provide an effect at 12 weeks post-therapy. However, the evidence is insufficient that Nd:YAG could yield more AL gain than non-surgical periodontal therapy alone. Further research will focus on the operating standard and interval of Nd:YAG laser in periodontal therapy.

Key words: Nd:YAG laser, Non-surgical periodontal therapy, Periodontitis, Meta analysis