OBJECTIVETo investigate the effects of different implant thread locations on stress distribution in implant and bone under concentrated load, and discuss the best design of location of implant thread.

METHODSThe stress in implant-bone interface of implants with different thread locations (model A, B, C, D), which were loaded in axial and oblique 450 to axle, were analyzed by Solidworks 2005 plus and Cosmos/works 7.0 software.

RESULTSThe stresses in cervical cortical bone of implant with model C were lower than others. But under oblique load, the stresses of implant and cancellous bone in model C were higher than model A. The stresses distribution of model B was obviously concentrated, and under axial load, all kinds of stresses in this model were higher than others. The stress distribution in model A and D were more even, the stress concentrated more on implant neck, upper part of cortical bone and the lowest thread on implant. The stresses in interface under oblique load were much higher than those under axial load.

CONCLUSIONThe location of thread has effect on stress distribution in implant-bone interface. More attention should be paid to it when we design implants, and we should try to avoid oblique load in implant prosthodontics.