Force and movement of non-osseointegrated implants: an in vitro study

Dental implants have enabled a dramatic increase in the quality of life for many partially edentulous and edentulous patents. Immediate loading of newly placed dental implants is a recent advancement that attempts to meet patient demand. However, immediate loading of a just placed implant may induce implant failure to osseointegrate. Some patients can generate a biting force that can reach approximately 1300 Newtons (N) in the posterior jaws. The magnitude of bite force that would cause failure of osseointegration of newly placed implants is currently unknown. It has been proposed that osseointegration would fail if an implant is luxated in bone more than 50 to 150 microns. Fibrous tissue, not bone, would form. This study investigated the quantity of various off-axial forces required to move a nonosseointegrated 4.3 x 13 mm implant 50 microns. The previously published pilot study for this study found that the amount of horizontal force required to displace an implant 50 microns was approximately 150 N. This study found that the force needed to move the implants 100 microns at a horizontal approach, 0 degrees, averaged 50 N, with a range of 23-79 N; at 22 degrees, averaged 52 N, with a range of 27-70 N; and at 60 degrees averaged 87 N, with a range of 33-105 N.