Ichikawa T, Kanitani H, Wigianto R, Kawamoto N, Matsumoto N
Department of Removable Prosthodontics, University of Tokushima, School of Dentistry, Japan.
Clin Oral Implants Res. 1997 Feb;8(1):18-22. doi: 10.1111/j.1600-0501.1997.tb00003.x.
Adequate bone quality and stress distribution to the bone are of decisive importance for implant success. The purpose of this in vitro study was to investigate the influence of bone quality on the stress distribution using 2 implant-bone mimicking models, simulating compact and cancellous bone quality. The resin model was made of an acrylic resin only simulating compact bone quality. The hybrid model was made of 2 kinds of materials, acrylic resin covered with a 1-mm layer of urethane to simulate cancellous bone quality. An implant was embedded in each model, and the abutment and suprastructures were connected to the implant. A strain gauge was placed perpendicular to the implant on the surface of the model and a small accelerometer was attached to the abutment. When an impact load was applied to the suprastructure, both strain and acceleration were measured. Both abutment acceleration and surface strain in the hybrid model decreased rapidly as time progressed when compared to the resin model. Abutment accelerations in the resin model were significantly lower than those in the hybrid model. In the hybrid model, the strain increased as the loading site was moved closer to the strain gauge. The influence of loading sites on strain in the resin model was greater than in the hybrid model. Therefore, the occlusal stress was distributed more widely in the hybrid model than in the resin model. This may indicate that occlusal stress in compact bone may have a tendency to concentrate in particular regions.
足够的骨质量以及骨所承受的应力分布对种植体的成功植入起着决定性作用。本体外研究的目的是使用两种模拟种植体-骨的模型，分别模拟密质骨和松质骨质量，来研究骨质量对应力分布的影响。树脂模型仅由模拟密质骨质量的丙烯酸树脂制成。混合模型由两种材料制成，丙烯酸树脂覆盖一层1毫米厚的聚氨酯以模拟松质骨质量。在每个模型中植入一个种植体，并将基台和上部结构与种植体相连。在模型表面垂直于种植体放置一个应变片，并在基台上连接一个小型加速度计。当对上颌结构施加冲击载荷时，同时测量应变和加速度。与树脂模型相比，混合模型中的基台加速度和表面应变随时间推移均迅速降低。树脂模型中的基台加速度显著低于混合模型中的基台加速度。在混合模型中，随着加载部位向应变片靠近，应变增加。加载部位对树脂模型中应变的影响大于混合模型。因此，混合模型中的咬合应力比树脂模型中的分布更广泛。这可能表明密质骨中的咬合应力可能有集中在特定区域的趋势。
