Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
3117850 | American Journal of Orthodontics and Dentofacial Orthopedics | 2010 | 9 Pages |
IntroductionThe purpose of this study was to determine the effect of miniscrew implant orientation on the resistance to failure at the implant-bone interface.MethodsMiniscrew implants (IMTEC, Ardmore, Okla) were placed in 9 human cadaver mandibles, oriented at either 90° or 45° to the bone surface, and tested to failure in pull-out (tensile) and shear tests. The line of applied force and the orientation of the implants aligned at 45° were either parallel or perpendicular to the maximum axis of bone stiffness. In the shear tests, the implants aligned at 45° were angled toward and opposing the axis of shear force.ResultsThe implants aligned at 90° had the highest force at failure of all the groups (342 ± 80.9 N; P <0.001). In the shear tests, the implants that were angled in the same direction as the line of force were the most stable and had the highest force at failure (253 ± 74.05 N; P <0.001). The implants angled away from the direction of force were the least stable and had the lowest force (87 ± 27.2 N) at failure.ConclusionsThe more closely the long axis of the implant approximates the line of applied force, the greater the stability of the implant and the greater its resistance to failure.