Pai Swathi, Bhat Vishal, Patil Vathsala, Naik Nithesh, Awasthi Swetank, Nayak Nithin
Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal, Manipal, Karnataka, India.
Department of Pharmacology, Melaka Manipal Medical College, Manipal, Karnataka, India.
J Int Soc Prev Community Dent. 2020 Jun 15;10(3):279-285. doi: 10.4103/jispcd.JISPCD_75_20. eCollection 2020 May-Jun.
Adhesive restoration does not depend primarily on the configuration of the shape of the cavity. Under varying loading conditions, it is essential to know the stress concentration and load transfer mechanism for distinct cavity shapes. The aim of this study was to evaluate and compare the biomechanical characteristics of various cavity shapes, namely oval, elliptical, trapezoidal, and rectangular shapes of class V cavities on mandibular premolars restored with amalgam, glass ionomer cement, and Cention N using three-dimensional (3D) finite element analysis.
A 3D prototype of a mandibular premolar was generated by Digital Imaging and Communications in Medicine (DICOM) images obtained from the cone beam computed tomography and imported to 3D modeling software tool, SpaceClaim. The four distinct load magnitudes of 100, 150, 200, and 250N were applied as a pressure load perpendicular to the lingual plane of the lingual cusp of the occlusal surface (normal load) and at 45° to same (oblique load). The stress distribution patterns and the maximum von Mises stresses were analyzed and compared.
The occlusal stresses were distributed from the force loading point in an approximate actinomorphic pattern, and when the force load was close to the margin, the stress was much greater.
Ovoid cavity showed lesser stress concentration and deformation for each of the tested restorative material.
粘结修复并不主要取决于窝洞的形状结构。在不同的加载条件下，了解不同窝洞形状的应力集中和载荷传递机制至关重要。本研究的目的是使用三维（3D）有限元分析，评估和比较用汞合金、玻璃离子水门汀和Cention N修复的下颌前磨牙V类洞的各种窝洞形状（即椭圆形、椭圆形、梯形和矩形）的生物力学特性。
通过从锥束计算机断层扫描获得的医学数字成像和通信（DICOM）图像生成下颌前磨牙的3D原型，并导入到3D建模软件工具SpaceClaim中。将100、150、200和250N这四种不同的载荷大小作为垂直于咬合面舌尖舌平面的压力载荷（法向载荷）以及与该平面成45°角的载荷（斜向载荷）施加。分析并比较应力分布模式和最大冯·米塞斯应力。
咬合应力从力加载点以近似辐射对称的模式分布，并且当力载荷靠近边缘时，应力要大得多。
对于每种测试的修复材料，卵形窝洞显示出较小的应力集中和变形。
