Abstract:

Objective To investigate the status of pathogenic bacteria and the changes of receptor activator of nuclear factor kappa-B ligand（RANKL）/osteoprotegerin（OPG） in patients with periodontitis ,and to provide a reference for the prevention and treatment of periodontitis.Methods A total of 130 patients with periodontitis were enrolled,and 50 healthy subjects were enrolled as control group. The periodontal probing depth（PD）,attachment loss（AL）,plaque index（PLI） and sulcus bleeding index（SBI） were compared between the 2 groups. The pathogenic bacteria were isolated and identified in the 2 groups. The RANKL and OPG levels in gingival crevicular fluid between the 2 groups were compared. The correlations with RANKL and OPG levels were evaluated.Results The PD,AL,PLI and SBI in periodontitis group were higher than those in control group（P<0.05）. The detection rates of Porphyromonas gingivalis,Actinomycetes,Capnocytophaga sputigena and Bacteroides toothdecay were higher in periodontitis group than those in control group（P<0.05）. The level of RANKL and RANKL/OPG in periodontitis group were higher than those in control group,and the OPG level was lower（P<0.05）. There was a negative correlation of OPG level with PD and AL in periodontitis group（P<0.05）. There was no correlation of RANKL level and RANKL/OPG with PD and AL（P>0.05）. There was no correlation of RANKL and OPG levels and RANKL/OPG with PLI and SBI（P>0.05）.Conclusions Porphyromonas gingivalis,Actinomycetes and Capnocytophaga sputigena are the main pathogenic bacteria for periodontitis. RANKL and OPG play roles in the destruction of alveolar bone tissue in patients with periodontitis.

Key words: Periodontitis, Pathogenic bacterium, Receptor activator of nuclear factor kappa-B ligand, Osteoprotegerin