BACKGROUND In some treatments using multiple dental implants, the implants are inserted in the bone with splinted or non-splinted implant prostheses. There are some reports about the influence of the splinted and non-splinted implants on stress distribution in the bone using the finite element method (FEM), and there is a controversy in the literature regarding whether the splinted or non-splinted implants prostheses reduce the stress generated on the implant-surrounding bone more efficiently. Additionally, the simple shape of the jaw bones with limited bone area was used for FEM analysis in many studies at the expense of accurate analysis. OBJECTIVE The aim of this study was to evaluate the difference in stress distribution in the bone between the splinted and non-splinted implants, and between completely and partially edentulous mandibles. METHODS The implants were inserted in the first premolar, second premolar, and first molar regions of the partial and complete mandibles, and the splinted and non-splinted crowns were attached to the implants. Vertical load (100 N) or oblique load (70 N, 30° from its long axis towards the lingual) was applied on the first premolar. RESULTS When vertical load was applied to the partially edentulous mandible model, the stress was concentrated intensively on the cortical bone around the first premolar regardless of whether splinted or non-splinted implants were used. On the other hand, the vertical load applied to the completely edentulous mandible model caused the stress to be concentrated intensively on the cortical bone around the first premolar with non-splinted implants. With respect to the oblique load, the stress was concentrated intensively on the cortical bone around the first premolar only with the non-splinted implants, in both the partial and complete mandibles. CONCLUSION This study shows the different stress distributions of the cortical bone around the implants between the partial and complete mandible. This indicates that the complete mandible should be used for the analysis of bone stress distribution around the implants using FEM.

中文翻译：

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夹板假牙和非夹板假牙周围部分和完全缺牙的下颌骨中应力分布的比较：有限元研究。

背景技术在使用多个牙科植入物的一些治疗中，将植入物通过夹板的或非夹板的植入物假体插入骨中。有报道说使用有限元方法（FEM）对夹板和非夹板植入物对骨骼中的应力分布的影响，并且关于夹板或非夹板植入物假体是否减少了应力，文献中存在争议。更有效地在植入物周围的骨头上产生应力。另外，在许多研究中，有限骨区域的颌骨的简单形状被用于有限元分析，而以精确分析为代价。目的本研究的目的是评估夹板植入物和非夹板植入物之间以及完全和部分缺牙的下颌骨之间的应力分布差异。方法将植入物插入部分和完整下颌骨的第一前磨牙区，第二前磨牙区和第一磨牙区，然后将带夹板的和不带夹板的牙冠连接到植入物上。在第一个前磨牙上施加垂直载荷（100 N）或倾斜载荷（70 N，从其长轴朝向舌头30°）。结果当对部分缺牙的下颌骨模型施加垂直载荷时，无论使用夹板植入物还是非夹板植入物，应力都集中在第一个前磨牙周围的皮质骨上。另一方面，施加到完全无牙的下颌骨模型的垂直载荷使应力集中在非夹板种植体的第一个前磨牙周围的皮质骨上。关于斜向载荷，应力仅在部分和完全下颌骨中以非夹板植入物集中在第一个前磨牙周围的皮质骨上。结论这项研究显示了部分下颌骨和完全下颌骨之间植入物周围的皮质骨的应力分布不同。这表明应使用完整的下颌骨来使用FEM分析植入物周围的骨应力分布。