Abstract:

Abstract:Objective To investigate the therapeutic effect of silver carboxymethyl chitosan（CMCT-Ag⁺）on experimental periodontitis in rats and the therapeutic mechanism,and provide evidence for preparing drug of treatment for periodontitis with high bactericidal action.Methods The first molar on the right of upper jaw in rats was bound with steel-wire.The gums of rats were spread with Porphyromonas gingivalis and the rats were fed with food of high density of glucose to induce rat periodontitis model.The rats were divided into six groups:control,model,Tinidazole,12.5,50.0 and 200.0 mg·kg^-1  CMCT-Ag⁺.Then the  bleeding index (BI),plaque index (PLI) and alveolar bone loss (ABL) in rats were observed. Results ① Compared with control rats,the model rats were easier gum blooding，dental plaque number increasing and conspicuous alveolar bone losing.The BI,PLI and ABL in model group were higher than those in control group（P<0.05 or P<0.01）.② Compared with model group,the BI and PLI in 50.0 mg·kg^-1 CMCT-Ag⁺group as well as BI,PLI and ABL in 200.0 mg·kg^-1  CMCT-Ag⁺ group were lower than those in model group（P<0.05 or P<0.01）.③ Compared with Tinidazole group,the BI and PLI in 12.5 mg·kg^-1  CMCT-Ag⁺group were higher than those in Tinidazole group（P<0.01）.④ Compared between CMCT-Ag⁺  treatment groups,the BI and PLI in 12.5 mg·kg^-1 group were higher than those in 200.0 mg·kg^-1 group （P<0.05）.
Conclusion CMCT-Ag⁺ can effectively treat rat periodontitis in a dose-dependent manner and 200.0 mg·kg^-1 CMCT-Ag⁺ can repair alveolar bone loss in periodontitis rats.The mechanism that CMCT-Ag⁺ can treat rat periodontitis  is due to inhibiting bacteria in periodontal tissue and preventing  dental plaque from forming.

Key words: carboxymethyl chitosan-Ag⁺；periodontitis；Porphyromonas gingivalis