Abstract: Objective To explore the expression of Emmprin in gingival crevicular fluid around implants and changes of clinical indexes as well as the relationship between them after implants′ overload.Methods 3 male adult Labradors were selected,with 3 implants on each side of their mandibles.After the healing 3 months later,the test groups were screwed with high level healing caps to simulate occlusal overload together with direct touch with teeth from upper jaws,while the control groups used low level healing caps as well as extraction of maxillary teeth.In altogether 12 weeks,gingival crevicular fluid around implants was extracted by periopaper every two weeks and preserved at-24 ℃.Then ELISA method was used to test Emmprin concentration in each specimen.Meanwhile,implant probing depth (iPD),implant gingival indexes (iGI) and implant blooding indexes (iBI) were tested.Data was statistically analyzed with paired t test and ANOVA.The significance level was 0.05.Results From 2nd week to 12th week,Emmprin of test groups increased obviously compared to control groups; the concentration increased before dropping,peaking at week 6.However,the concentration of control groups kept steady all along.The differences were significant.Besides,iPD,iGI and iBI of test groups altered significantly,with the values peaking between week 8 and 10.Conclusions Occlusal traumas can change the concentration of Emmprin in gingival crevicular fluid around the implants,which peaks at week 6.iPD,iGI and iBI of overloaded implants change significantly,peaking between week 8 and 10.Regarding the implants exposed to overload occlusal force,the increase of Emmprin concentration occurs ahead of other clinical indexes,which indicates that Emmprin can be a potential signal for peri-implantitis.

Key words: overload, peri-implantitis, Emmprin, clinical indexes, Labrador, peri-implant gingival crevicular fluid