Srirekha A, Bashetty Kusum
Department of Conservative Dentistry and Endodontics, The Oxford Dental College, Hospital and Research Centre, Bangalore, Karnataka, India.
J Conserv Dent. 2013 Mar;16(2):157-61. doi: 10.4103/0972-0707.108200.
The present comparative analysis aimed at evaluating the mechanical behavior of various restorative materials in abfraction lesion in the presence and absence of occlusal restoration.
A three-dimensional finite-element analysis was performed. Six experimental models of mandibular first premolar were generated and divided into two groups (groups A and B) of three each. All the groups had cervical abfraction lesion restored with materials and in addition group A had class I occlusal restoration. A load of 90 N, 200 N, and 400 N were applied at 45° loading angle on the buccal inclines of buccal cusp and Von Mises stresses was chosen for analysis.
In all the models, the values of stress recorded at the cervical margin of the restorations were at their maxima. Irrespective of the occlusal restoration, all the materials performed well at 90 N and 200 N. At 400 N, only low-shrink composite showed stresses lesser than its tensile strength indicating its success even at higher load.
Irrespective of occlusal restoration, restorative materials with low modulus of elasticity are successful in abfraction lesions at moderate tensile stresses; whereas materials with higher modulus of elasticity and mechanical properties can support higher loads and resist wear.
The model allows comparison of different restorative materials for restoration of abfraction lesions in the presence and absence of occlusal restoration. The model can be used to validate more sophisticated computational models as well as to conduct various optimization studies.
本比较分析旨在评估在存在和不存在咬合修复的情况下,各种修复材料在牙体楔状缺损病变中的力学行为。
进行三维有限元分析。生成下颌第一前磨牙的六个实验模型,并分为两组(A组和B组),每组三个。所有组的颈部楔状缺损病变均用材料修复,此外,A组进行I类咬合修复。在颊尖的颊斜面以45°加载角施加90 N、200 N和400 N的载荷,并选择冯·米塞斯应力进行分析。
在所有模型中,修复体颈部边缘记录的应力值均为最大值。无论是否有咬合修复,所有材料在90 N和200 N时表现良好。在400 N时,只有低收缩复合材料的应力小于其拉伸强度,表明即使在较高载荷下也能成功。
无论是否有咬合修复,低弹性模量的修复材料在中等拉应力下对牙体楔状缺损病变修复成功;而具有较高弹性模量和力学性能的材料可以承受更高的载荷并抵抗磨损。
该模型允许比较在存在和不存在咬合修复的情况下用于修复牙体楔状缺损病变的不同修复材料。该模型可用于验证更复杂的计算模型以及进行各种优化研究。