Huang Heng-Li, Huang Jehn-Shyun, Ko Ching-Chang, Hsu Jui-Ting, Chang Chih-Han, Chen Michael Y C
Institute of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.
Clin Oral Implants Res. 2005 Aug;16(4):466-72. doi: 10.1111/j.1600-0501.2005.01124.x.
Three-dimensional finite element (FE) models of splinted prosthetic crowns were studied and stress analyses were evaluated with different types of implant support, including standard, wide or two implant(s) for partial, posterior edentulous restorations.
The FE models were constructed based on a cadaver mandible containing the 2nd premolar and the 1st molar. The crowns of these two teeth were modeled as connected and disconnected to mimic the splinted and non-splinted designs, respectively. One standard implant was placed at the premolar region, while three types of implant support, one at a time (the standard implant, wide implant and two implants), were used to support the molar crown. A 100 N oblique load was applied to the buccal cusp on each crown. The FE simulation was validated experimentally via strain gauge measurement.
The experimental data were well correlated with the FE predictions (r(2)=0.97). When compared with the standard implant used in the molar area, the wide implant and two implants reduced the peak stress in crestal bone by 29-37% for both splinted and non-splinted cases. Inserting the standard implant into both the premolar and molar area, the bone stresses were identical for splinted and non-splinted designs. However, splinting the adjacent crowns has shown to decrease the bone stresses at the premolar region by 25%, while the wide implant or two implants were placed at the molar region.
The biomechanical advantages of using the wide implant or two implants are almost identical. The benefit of load sharing by the splinted crowns is notable only when the implants on the premolar and molar regions have different supporting ability.
研究夹板式修复冠的三维有限元(FE)模型,并评估不同类型种植体支持下的应力分析,包括用于部分后牙缺失修复的标准型、宽型或两颗种植体。
基于包含第二前磨牙和第一磨牙的尸体下颌骨构建有限元模型。将这两颗牙齿的冠分别建模为相连和不相连,以分别模拟夹板式和非夹板式设计。在第一前磨牙区域植入一枚标准种植体,同时使用三种类型的种植体支持方式(每次一种,即标准种植体、宽种植体和两颗种植体)来支持磨牙冠。在每个冠的颊尖施加100 N的斜向载荷。通过应变片测量对有限元模拟进行实验验证。
实验数据与有限元预测结果具有良好的相关性(r² = 0.97)。与磨牙区域使用的标准种植体相比,对于夹板式和非夹板式情况,宽种植体和两颗种植体可使牙槽嵴顶骨的峰值应力降低29% - 37%。在第一前磨牙和磨牙区域均植入标准种植体时,夹板式和非夹板式设计的骨应力相同。然而,当在磨牙区域植入宽种植体或两颗种植体时,将相邻冠进行夹板固定可使前磨牙区域的骨应力降低25%。
使用宽种植体或两颗种植体的生物力学优势几乎相同。仅当前磨牙和磨牙区域的种植体具有不同的支持能力时,夹板式冠分担载荷的益处才显著。