RESUMO
Objective:To investigate the effects of repeated high acceleration(+Gz)on implant osseointegration in SD rats.Methods:18 SD rats were divided into+Gz and control groups randomly(n=9),and 1 implant was placed in each femur of the rat's lower limb.24 hours postoperatively,the experimental rats were exposed to+Gz of 4 to 9 G with 1 G/s environment 3 times a week,while the con-trol rats were fed normally.3 rats from each of the 2 groups were sacrificed at 2,4 and 8 weeks after implantation.Micro-CT,sequential fluorescence double labeling,and histological examination were perfomed for the analysis of implant osseointegration.Results:The bone volume fraction(BV/TV),trabecular number(Tb.N),mineral apposition rate(MAR),implant-bone contact rate(BIC)and bone area in implant thread(BA)of the+Gz group were significantly lower than those of the control group at 2 weeks(P＜0.05),and so as to MAR,BA at 4 weeks(P＜0.05),while there was no significant difference of the parameters at 8 weeks after implantation.Conclusion:In SD rats early exposure to+Gz environment postoperatively may have a negative effect on initial osseointegration by slowing bone forma-tion.However,it will not lead to poorer bone mass when sustained over a long period.