Santos-Filho Paulo César Freitas, Veríssimo Crisnicaw, Soares Paulo Vinícius, Saltarelo Rebeca Carniello, Soares Carlos José, Marcondes Martins Luis Roberto
Department of Restorative Dentistry and Dental Materials, Dentistry School, Federal University of Uberlandia, Minas Gerais, Brazil.
Department of Restorative Dentistry and Dental Materials, Dentistry School, Federal University of Uberlandia, Minas Gerais, Brazil.
J Endod. 2014 Jan;40(1):119-23. doi: 10.1016/j.joen.2013.09.034. Epub 2013 Oct 27.
The aim of this study was to evaluate the influence of post system, length, and ferrule on biomechanical behavior of endodontically treated anterior teeth.
The investigation was conducted by using laboratory tests and 3-dimensional finite element analysis. Eighty bovine incisors were selected and divided into 8 treatment groups (n = 10) with absence of ferrule and 2.0 mm of ferrule, restored with glass fiber post or cast post and core, and 12.0 and 7.0 mm of post length. The specimens were loaded at 135° angle, and the strain was measured by using strain gauge method. Specimens were subsequently loaded until fracture. Strain and fracture resistance results were analyzed by 3-way analysis of variance and Tukey honestly significant difference tests (α = 0.05). Three-dimensional models of a maxillary central incisor were generated with the same treatment variations used in laboratory tests. Each model was subjected to 100 N oblique loads. Results were evaluated by von Mises criterion.
Ferrule was a determining factor in the strain, fracture resistance, and fracture pattern. In the absence of ferrule, the use of fiberglass posts represents a conservative choice from the standpoint of the fracture patterns observed. The length of 7 mm for cast post and cores produced high rates of root fractures. Finite element analysis showed that glass fiber post showed homogeneous stress distribution, whereas cast post showed stress concentration into root canal.
Post length influenced only the cast post strain and stress distribution. The ferrule groups always showed more satisfactory stress distribution and fracture resistance.
本研究的目的是评估桩系统、长度和桩核冠对经根管治疗的前牙生物力学行为的影响。
采用实验室测试和三维有限元分析进行研究。选取80颗牛切牙，分为8个治疗组（n = 10），分别有无桩核冠以及桩核冠为2.0 mm，用玻璃纤维桩或铸造桩核修复，桩长度分别为12.0 mm和7.0 mm。标本以135°角加载，采用应变片法测量应变。随后对标本加载直至断裂。通过三因素方差分析和Tukey真实显著性差异检验（α = 0.05）分析应变和抗折强度结果。使用与实验室测试相同的治疗变量生成上颌中切牙的三维模型。每个模型承受100 N的斜向载荷。根据冯·米塞斯准则评估结果。
桩核冠是应变、抗折强度和骨折模式的决定因素。在没有桩核冠的情况下，从观察到的骨折模式来看，使用玻璃纤维桩是一种保守的选择。铸造桩核长度为7 mm时产生较高的牙根骨折率。有限元分析表明，玻璃纤维桩应力分布均匀，而铸造桩应力集中在根管内。
桩长度仅影响铸造桩的应变和应力分布。桩核冠组始终显示出更令人满意的应力分布和抗折强度。
