School of Dentistry, Faculty of Medicine, University of Novi Sad, Hajduk Veljkova 3, 21000, Novi Sad, Serbia.
Photonics Centre, Institute of Physics, University of Belgrade, Pregravica 118, 11080, Belgrade, Serbia.
Med Biol Eng Comput. 2018 Oct;56(10):1875-1886. doi: 10.1007/s11517-018-1824-1. Epub 2018 Apr 10.
In order to investigate the influence of cusp reduction, cavity isthmus width, and restorative material on stress values in premolar with mesio-occlusal-distal (MOD) cavity, numerical simulations were done on three-dimensional (3D) models of a maxillary second premolar designed using computerized tomography (CT) scan images. The use of four restorative materials (direct resin composite, direct resin composite with resin-modified glass-ionomer cement as the base, indirect resin composite, ceramic), three cavity preparation designs (without cusp coverage, 2-mm palatal cusp coverage, 2-mm palatal and buccal cusp coverage), and two cavity isthmus widths (1/2 and 2/3 intercuspal width) were simulated. After applying a static load of 200 N on the occlusal surface of the tooth, von Mises stresses in the enamel, dentin, and restoration were calculated using finite element analysis (FEA). Stress values in the enamel were primarily influenced by cavity preparation design, while restorative material showed higher contribution in dentin. The lowest stress values were obtained in models with cusp coverage and indirect restorations. Cavity isthmus width had minimal influence on stress values in tooth structures. None of the investigated factors determined stress values in the restoration. In conclusion, the use of ceramic restoration covering both palatal and buccal cusp provided the most favourable stress distribution of premolars with MOD cavity. Graphical abstract ᅟ.
为了研究牙尖削减、窝沟峡部宽度和修复材料对上颌第二前磨牙近中-颊舌-远中（MOD）窝洞的应力值的影响，使用计算机断层扫描（CT）图像设计的上颌第二前磨牙三维（3D）模型进行了数值模拟。模拟了四种修复材料（直接树脂复合材料、直接树脂复合材料基底为树脂改性玻璃离子水门汀、间接树脂复合材料、陶瓷）、三种窝洞制备设计（无牙尖覆盖、2mm 腭牙尖覆盖、2mm 腭牙尖和颊牙尖覆盖）和两种窝沟峡部宽度（1/2 和 2/3 牙尖间宽度）。在牙的咬合面上施加 200N 的静态载荷后，使用有限元分析（FEA）计算釉质、牙本质和修复体中的 von Mises 应力。釉质中的应力值主要受窝洞制备设计的影响，而修复材料对牙本质的贡献更高。牙尖覆盖和间接修复模型的应力值最低。窝沟峡部宽度对牙体结构的应力值影响最小。在所研究的因素中，没有一个因素决定修复体的应力值。总之，使用覆盖颊侧和腭侧牙尖的陶瓷修复体可提供 MOD 窝洞的前磨牙最有利的应力分布。
