Biomechanics Group, Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
J Prosthet Dent. 2010 Nov;104(5):306-17. doi: 10.1016/S0022-3913(10)60146-1.
Unresolved controversy exists concerning the remaining coronal tooth structure of anterior endodontically treated teeth and the best treatment option for restoring them.
The purpose of this study was to evaluate the effect of post, core, crown type, and ferrule presence on the deformation, fracture resistance, and fracture mode of endodontically treated bovine incisors.
One hundred and eighty bovine incisors were selected and divided into 12 treatment groups (n=15). The treatment variations were: with or without ferrule, restored with cast post and core, glass fiber post with composite resin core, or glass fiber post with fiber-reinforced core, and metal- or alumina-reinforced ceramic crown (n=15). The restored incisors were loaded at a 135-degree angle, and the deformation was measured using strain gauges placed on the buccal and proximal root surfaces. Specimens were subsequently loaded to the point of fracture. Strain and fracture resistance results were analyzed by 3-way ANOVA and Tukey HSD tests (α=.05).
Ferrule presence did not significantly influence the buccal strain and fracture resistance for the ceramic crown groups, irrespective of core and crown type. Ferrule presence resulted in lower strains and higher fracture resistance in the metal crown groups, irrespective of core. The cast post and core showed lower strain values than groups with glass fiber posts when restored with metal crowns.
Core type did not affect the deformation and fracture resistance of endodontically treated incisors restored with alumina-reinforced ceramic crowns. The presence of a ferrule improved the mechanical behavior of teeth restored with metal crowns, irrespective of core type.
关于根管治疗后的前牙剩余冠部牙体结构以及最佳修复方法，仍存在争议。
本研究旨在评估桩核、冠类型和 （或） 全瓷冠基底的存在对根管治疗后的牛切牙变形、抗折力和断裂模式的影响。
选择 180 颗牛切牙，分为 12 个治疗组（n=15）。处理方式包括：有或无基底，采用铸造桩核、玻璃纤维桩复合树脂核、玻璃纤维桩纤维增强核修复，以及金属或氧化铝增强陶瓷冠修复（n=15）。将修复后的切牙以 135°角加载，通过放置在颊侧和近中根表面的应变计测量变形。随后将标本加载至断裂点。通过三因素方差分析和 Tukey HSD 检验（α=.05）分析应变和抗折力结果。
无论核和冠类型如何，基底的存在均未显著影响陶瓷冠组的颊侧应变和抗折力。基底的存在使金属冠组的应变降低，抗折力增加，无论核的类型如何。当用金属冠修复时，铸造桩核的应变值低于玻璃纤维桩组。
核心类型不会影响氧化铝增强陶瓷冠修复的根管治疗后切牙的变形和抗折力。无论核的类型如何，基底的存在均改善了金属冠修复的牙齿的力学性能。
