可切削硅酸锂全瓷冠的力学差异性研究

发布时间：2018-08-19 19:25

【摘要】：可切削硅酸锂陶瓷具有很好的色泽和较高的抗弯强度,它既可用于单层冠,也可以用作氧化锆基底冠的饰面瓷,再通过烧结或者粘接方式合成全瓷冠。本文研究了单层冠、烧结双层冠和粘接双层冠等3种结构形式的全瓷冠修复体在典型载荷作用下应力分布差异。建立了下颌第一磨牙单层冠、烧结双层冠和粘接双层冠等3种全瓷冠的三维数值模型,分别对其施加垂直集中载荷和八点均布载荷两种典型载荷,通过数值计算分析3种全瓷冠各部分的应力极值和应力分布。结果表明,3种瓷冠在两种载荷作用下的最大应力均小于材料的弯曲强度。烧结双层冠和粘接双层冠应力分布形式大体相同,与单层冠应力分布趋势不同。粘接双层冠与烧结双层冠相比,饰面瓷应力更大。在采用可切削硅酸锂陶瓷单层冠作为磨牙修复体时,在多次咀嚼载荷作用下高应力区可能导致全瓷冠的使用寿命缩短。与烧结双层冠相比,粘接双层冠的饰面瓷可能存在更大崩瓷的风险。本文结论可为可切削硅酸锂陶瓷材料在实际全瓷冠修复临床应用中提供参考意见。
[Abstract]:The machinable lithium silicate ceramic has good color and high flexural strength. It can be used not only for monolayer crown, but also for decorative porcelain of zirconia substrate crown. All ceramic crowns can be synthesized by sintering or bonding. In this paper, the stress distribution of three types of all-ceramic crown restorations, such as monolayer crown, sintered double-layer crown and bonded double-layer crown, were studied under typical load. Three-dimensional numerical models of three kinds of all-ceramic crowns, such as monolayer crown, sintered double-layer crown and bonded double-layer crown, were established, and two typical loads, vertical concentrated load and eight-point uniform load, were applied to them. The stress extremum and stress distribution of three kinds of all-ceramic crowns were analyzed by numerical calculation. The results show that the maximum stress of the three ceramic crowns under two loads is less than the bending strength of the materials. The stress distribution of sintered double crown and bonded double crown is approximately the same, which is different from that of monolayer crown. Compared with sintered double-layer crowns, the stress of veneer porcelain is greater than that of bonded double-layer crowns. When the machinable lithium silicate ceramic monolayer crown is used as the molar restoration, the high stress region under multiple masticatory loads may shorten the service life of the all-ceramic crown. Compared with sintered double-layer crowns, there may be a greater risk of porcelain collapsing by bonding double-layer crowns. Conclusion this paper can provide reference for the clinical application of machinable lithium silicate ceramic material in practical all-ceramic crowns.
【作者单位】：上海市应用数学和力学所;同济大学附属第十人民医院口腔科;上海大学力学系;
【基金】：国家自然科学基金(11372173)
【分类号】：R783.1

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