[复合树脂厚度对磨牙牙尖劈裂后牙体修复的影响]
The Effect of Composite Thickness on the Stress Distribution Pattern of Restored Premolar Teeth with Cusp Reduction.
机构信息
Dental Research Center, Research Institute of Dental Sciences, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Iranian Center for Endodontic Research, Research Institute of Dental Sciences, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
出版信息
J Prosthodont. 2017 Jul;26(5):440-445. doi: 10.1111/jopr.12422. Epub 2015 Dec 8.
PURPOSE
Different thicknesses of restorative material can alter the stress distribution pattern in remaining tooth structure. The assumption is that a thicker composite restoration will induce a higher fracture resistance. Therefore, the present study evaluated the effect of composite thickness on stress distribution in a restored premolar with cusp reduction.
MATERIALS AND METHODS
A 3D solid model of a maxillary second premolar was prepared and meshed. MOD cavities were designed with different cusp reduction thicknesses (0, 0.5, 1, 1.5, 2.5 mm). Cavities were restored with Valux Plus composite. They were loaded with 200 N force on the occlusal surface in the direction of the long axis. Von Mises stresses were evaluated with Abaqus software.
RESULTS
Stress increased from occlusal to gingival and was maximum in the cervical region. The stressed area in the palatal cusp was more than that of the buccal cusp. Increasing the thickness of composite altered the shear stress to compressive stress in the occlusal area of the teeth.
CONCLUSION
The model with 2.5 mm cusp reduction exhibited the most even stress distribution.
目的
修复材料的不同厚度会改变剩余牙体结构的应力分布模式。假设较厚的复合树脂修复体将产生更高的抗断裂能力。因此，本研究评估了在磨牙颊尖和舌尖少量磨除后，复合树脂厚度对前磨牙牙体应力分布的影响。
材料与方法
制备并网格化上颌第二前磨牙的三维实体模型。设计 MOD 窝洞，颊尖和舌尖少量磨除的厚度分别为 0、0.5、1、1.5 和 2.5mm。使用 Valux Plus 复合树脂进行窝洞修复。在长轴方向的牙合面施加 200N 的力。使用 Abaqus 软件评估 Von Mises 应力。
结果
应力从牙合面到龈方逐渐增加，在颈缘区达到最大值。腭尖的受力区域大于颊尖。增加复合树脂的厚度会改变牙合面区域的剪切应力为压应力。
结论
颊尖和舌尖磨除 2.5mm 的模型显示出最均匀的应力分布。
Zotero 插件