Cook S D, Salkeld S L, Gaisser D M, Wagner W R
Department of Orthopaedic Surgery, Tulane University School of Medicine, New Orleans, LA 70112.
J Oral Implantol. 1993;19(4):307-13.
The interface attachment strength and histology of an elliptical hydroxylapatite-coated (HA) endosseous dental implant were compared with those of an otherwise identical cylindrical dental implant. The implant designs were tested in two canine in vivo models: healed mandibular extraction sites and the femoral unicortical plug. The implants were evaluated 15 weeks post-implantation. The elliptical geometry of the dental implant was not found significantly to enhance axial pull-out strength or torsional implant-bone interface attachment in either in vivo model. The cylindrical implant absorbed more energy to failure in both the mandible and the femur; however, the difference was not statistically significant. Differences in the interface shear attachment strength between the two models (mandible and femur) were statistically significant when the maximum load to failure was normalized by the actual bone contact surface area. In all cases, femoral values were significantly greater. Examination of HA-coating thickness revealed uniform coatings on both implant types which were well maintained in vivo. Mechanical failure occurred primarily at the metal substrate-HA interface in each type of implant in both models. The amounts of bone apposition to both implants in both models were identical. Coating break-up and inflammatory response to the particulate debris were minimal.
将椭圆形羟基磷灰石涂层（HA）骨内牙种植体与其他方面相同的圆柱形牙种植体的界面附着强度和组织学进行了比较。在两种犬体内模型中对种植体设计进行了测试：愈合的下颌拔牙位点和股骨单皮质骨块。在植入后15周对种植体进行评估。在任何一种体内模型中，均未发现牙种植体的椭圆形几何形状能显著提高轴向拔出强度或扭转种植体-骨界面附着。圆柱形种植体在颌骨和股骨中吸收更多能量直至失效；然而，差异无统计学意义。当将最大失效载荷按实际骨接触表面积进行归一化时，两种模型（颌骨和股骨）之间的界面剪切附着强度差异具有统计学意义。在所有情况下，股骨的值均显著更高。对HA涂层厚度的检查显示，两种种植体类型上的涂层均均匀，且在体内保持良好。在两种模型中，每种类型的种植体主要在金属基底-HA界面处发生机械失效。在两种模型中，两种种植体的骨附着量相同。涂层破裂和对颗粒碎片得炎症反应均最小。
