Department of Periodontology and Biomaterials, Radboud University Medical Center, Nijmegen, The Netherlands.
Clin Oral Implants Res. 2010 Feb;21(2):213-20. doi: 10.1111/j.1600-0501.2009.01823.x.
The aim of this biomechanical study was to assess the interrelated effect of both surface roughness and surgical technique on the primary stability of dental implants.
For the experiment, 160 screw-designed implants (Biocomp), with either a machined or an etched surface topography, were inserted into polyurethane foam blocks (Sawbones). As an equivalent of trabecular bone, a density of 0.48 g/cm(3) was chosen. To mimic the cortical layer, on top of these blocks short-fibre-filled epoxy sheets were attached with a thickness varying from 0 to 2.5 mm. The implant sites were prepared using either a press-fit or an undersized technique. To measure the primary stability of the implant, both the insertion and the removal torques were scored.
Independent of the surgical technique used, both implant types showed an increased insertion and removal torque values with increasing cortical thickness, although >2 mm cortical layer no further increase in insertion torque was observed. In the models with only trabecular bone (without cortical layer) and with a 1 mm cortical layer, both implant types showed a statistically higher insertion and removal torque values for undersized compared with the press-fit technique. In addition, etched implants showed a statistically higher insertion and removal torque mean values compared with machined implants. In the models with 2 and 2.5 mm cortical layers, with respect to the insertion torque values, no effect of either implantation technique or implant surface topography could be observed.
The placement of etched implants in synthetic bone models using an undersized preparation technique resulted in enhanced primary implant stability. A correlation was found between the primary stability and the cortical thickness. However, at or above a cortical thickness of 2 mm, the effect of both an undersized surgical approach, as also the presence of a roughened (etched) implant surface, had no extra effect. Besides the mechanical aspects, the biological effect of undersized drilling, i.e. the bone response on the extra insertion torque forces should also be elucidated. Therefore, additional in vivo studies are needed.
本生物力学研究旨在评估表面粗糙度和手术技术对牙种植体初始稳定性的相互影响。
在实验中，将 160 个螺丝设计的植入物（Biocomp），具有机械加工或蚀刻表面形貌，插入到聚氨酯泡沫块（Sawbones）中。作为小梁骨的等效物，选择密度为 0.48 g/cm³。为了模拟皮质层，在这些块的顶部附上了厚度从 0 到 2.5 毫米的短纤维填充环氧树脂片。使用压配合或小尺寸技术制备植入物部位。为了测量植入物的初始稳定性，记录了插入和移除扭矩。
无论使用哪种手术技术，两种植入物类型的皮质厚度增加时，插入和移除扭矩值都增加，尽管皮质层 >2 毫米时，插入扭矩值不再增加。在只有小梁骨（无皮质层）和 1 毫米皮质层的模型中，与压配合技术相比，两种植入物类型的小尺寸技术的插入和移除扭矩值均更高。此外，与机械加工植入物相比，蚀刻植入物的插入和移除扭矩平均值更高。在具有 2 和 2.5 毫米皮质层的模型中，就插入扭矩值而言，植入技术或植入物表面形貌均无影响。
在使用小尺寸预备技术的合成骨模型中放置蚀刻植入物可增强初始植入物稳定性。发现初始稳定性与皮质厚度之间存在相关性。然而，在皮质厚度达到或超过 2 毫米时，小尺寸手术方法的存在以及粗糙（蚀刻）植入物表面的存在均无额外影响。除了机械方面，还应阐明小尺寸钻孔的生物学效应，即额外插入扭矩力对骨的反应。因此，需要进行额外的体内研究。
