Biomechanics Group, Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
J Prosthet Dent. 2013 Aug;110(2):116-26. doi: 10.1016/S0022-3913(13)60350-9.
Teeth restored with posts are more frequently associated with bone loss, but there is no evidence to suggest that the post type and the presence of bone loss influence biomechanical behavior.
The purpose of this study was to evaluate the effect of alveolar bone loss, post type, and ferrule presence on the biomechanical behavior of endodontically treated maxillary canines.
For the experimental analysis, 40 human canine teeth were selected and divided into 8 experimental groups (n=5) according to 3 treatment variations: with or without 5.0 mm of bone loss (bl), with or without a ferrule, and restored with cast post and cores or glass fiber post. The restored canines were loaded at 15 degrees, and deformation was measured with strain gauges placed on the buccal and proximal root surfaces. Strain results were analyzed by 3-way analysis of variance (ANOVA) and the Tukey HSD tests (α=.05). For the finite element analysis, eight 3D models were created by following the same variations of the experimental analysis. The models were analyzed by using the maximum principal stress criteria for stress distribution analysis.
The absence of a ferrule significantly increased the buccal and proximal strain values. The post type influenced the stress distribution, mainly at the interface of post and dentin. The bone loss significantly increased the stress concentration and strain values, mainly on root dentin and surrounding cortical bone.
The presence of a ferrule improved the mechanical behavior. The 5.0 mm of bone loss significantly increased the stress concentration and the strain on the root dentin.
用桩修复的牙齿更容易发生骨丢失，但没有证据表明桩的类型和骨丢失的存在会影响生物力学行为。
本研究的目的是评估牙槽骨丢失、桩类型和金属全冠的存在对上颌尖牙根管治疗后生物力学行为的影响。
在实验分析中，选择了 40 个人类尖牙，根据 3 种治疗变化分为 8 个实验组（n=5）：有无 5.0mm 的骨丢失（bl），有无金属全冠，以及用铸造桩核或玻璃纤维桩修复。用 15 度加载修复后的尖牙，并在颊侧和近中根表面放置应变片测量变形。应变结果用三因素方差分析（ANOVA）和 Tukey HSD 检验（α=.05）进行分析。对于有限元分析，根据实验分析的相同变化创建了 8 个 3D 模型。通过最大主应力准则对模型进行分析，以评估应力分布。
没有金属全冠会显著增加颊侧和近中侧的应变值。桩的类型影响了应力分布，主要在桩和牙本质的界面处。骨丢失显著增加了应力集中和根牙本质的应变值，主要在根牙本质和周围皮质骨上。
金属全冠的存在改善了力学行为。5.0mm 的骨丢失显著增加了根牙本质的应力集中和应变。
