Objectives

The purpose of this study was to estimate the fatigue life of premolars restored with two dental ceramics, lithium disilicate (LD) and polymer infiltrated ceramic (PIC) using the numerical method and compare it with the published in vitro data.

Methods

A premolar restored with full-coverage crown was digitized. The volumetric shape of tooth tissues and crowns were created in Mimics^®. They were transferred to IA-FEMesh for mesh generation and the model was analyzed with Abaqus. By combining the stress distribution results with fatigue stress–life (S–N) approach, the lifetime of restored premolars was predicted.

Results

The predicted lifetime was 1,231,318 cycles for LD with fatigue load of 1400 N, while the one for PIC was 475,063 cycles with the load of 870 N. The peak value of maximum principal stress occurred at the contact area (LD: 172 MPa and PIC: 96 MPa) and central fossa (LD: 100 MPa and PIC: 64 MPa) for both ceramics which were the most seen failure areas in the experiment. In the adhesive layer, the maximum shear stress was observed at the shoulder area (LD: 53.6 MPa and PIC: 29 MPa).

Significance

The fatigue life and failure modes of all-ceramic crown determined by the numerical method seem to correlate well with the previous experimental study.

中文翻译：

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CAD / CAM陶瓷冠修复前磨牙的数值疲劳分析

目标

这项研究的目的是使用数值方法评估用两种牙科陶瓷二硅酸锂（LD）和聚合物浸润陶瓷（PIC）修复的前磨牙的疲劳寿命，并将其与已发表的体外数据进行比较。

方法

用全覆盖冠修复的前磨牙被数字化。牙体硬组织和冠的体积形状是在模仿创建^®。将它们转移到IA-FEMesh进行网格生成，并使用Abaqus分析模型。通过将应力分布结果与疲劳应力-寿命（SN）方法相结合，可以预测恢复的前磨牙的寿命。

结果

LD的预期寿命为1,231,318个循环，疲劳载荷为1400 N，而PIC的预测寿命为475,063个循环，载荷为870N。最大主应力的峰值出现在接触区域（LD：172 MPa和PIC：两种陶瓷均为96 MPa）和中央窝（LD：100 MPa，PIC：64 MPa），这是实验中最常见的破坏区域。在粘合剂层中，在肩部区域观察到最大剪切应力（LD：53.6 MPa，PIC：29 MPa）。

意义

用数值方法确定的全瓷冠的疲劳寿命和失效模式似乎与以前的实验研究很好地相关。