Abstract： Objective To establish rat models of occlusal trauma and periodontitis,and to investigate the effect of occlusal trauma on the occurrence and development of experimental periodontitis.Methods Seventy-two SD rats were randomly divided into three groups:control group(group A),experimental periodontitis group(group B) and occlusal trauma plus experimental periodontitis group(group C).Six rats were randomly put to death in each group at 1,4,8 and 12 weeks after treatment,respectively.The pathological changes in periodontal tissues of mandibular first molar were observed under the light microscope and the number of osteoclast was determined.Results In each period,the number of osteoclast in group B or group C was significantly higher than that in group A(P<0.05),while the number in group C was significantly higher than that in group B(P<0.01).From 1 to 12 weeks,the number of osteoclast was not changed in group A(P>0.05),but obviously increased in group B and group C(P<0.01).Typical peridontitis appeared at 4 weeks in group C,while at 8 weeks in group C.Conclusion Occlusal trauma as a local factor can increase the incidence and development of periodotitis.
2011, Vol. 53 
