Abstract: Objective To evaluate the effect of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser assisting initial therapy of periodontal diseases by Meta-analysis. Methods The periodical literature,conference paper and academic dissertation of Chinese were scanned by electronic retrieval and manual search,and then the clinical studies which compared Nd:YAG laser assisting initial therapy of periodontal diseases to initial therapy of periodontal diseases alone were collected.According to inclusion and exclusion criteria,the quality assessment of these included studies,the data extraction were done and the heterogeneity test,the Mate-analysis were conducted.We also test the publication bias of the outcome by Meta-analysis. Results We adopted ultimately 8 studies into our research,of which the observation index was effective rate of 5 studies, while for remaining 3 studies the observation targets were PD(pocket depth),AL(attachment loss) and BI(bleeding index).There were no statistically significant differences in all the results of meta-analysis,except PD before and 3 months after SRP by Nd:YAG laser assisting initial therapy of periodontal diseases,accordingly no significant publication bias was found. Conclusions There was significant improvement in clinical efficiency on PD before and 3 months after SRP(scaling and root planning,SRP) by Nd:YAG laser assisting initial therapy of periodontal diseases,while the rest outcomes should be researched further patiently.

Key words: Nd: YAG laser, initial therapy of periodontal diseases, periodontitis, Meta analysis