Force required to luxate a newly placed dental implant in bone: an in vitro pilot study

Immediate loading of newly placed dental implants is a consideration when attempting to meet patients' demands. However, immediate loading may induce implant failure to osseointegrate, particularly in the case of a patient who can generate a biting force that can reach approximately 1300 Newtons (N) in the posterior jaws. The range of biting forces that prevent osseointegration of newly placed implants is currently unknown. However, it is suspected that osseointegration may fail if an implant is luxated in bone more than 50 microm, in which case fibrous tissue will be formed instead of bone. This pilot study was focused on finding the amount of horizontal off-axial force required to move a nonosseointegrated 4.3 x 13-mm implant 50 microm. The initial data show that the amount of horizontal force required to displace such an implant by 50 microm was on the order of 150 N. Assuming that the angle between the direction of the biting force and the vertical lies between 0 degrees and 20 degrees, our data show that a 4.3 x 13-mm implant may fail to osseointegrate for biting forces that are as low as 440 N. One implication of our study is that implants having smaller diameters may move and fail to osseointegrate for even lower biting forces.