Department of Conservative Dentistry, Dental College, Wonkwang University, Iksan, Korea.
J Endod. 2010 Feb;36(2):297-301. doi: 10.1016/j.joen.2009.10.010. Epub 2009 Dec 10.
This study compared the fracture resistances and the failure patterns of 100 simulated mandibular premolars of a different number of coronal walls (zero to four walls) with or without fiber-reinforced composite (FRC) posts. In addition, the photoelastic stress distribution was analyzed.
The fracture resistance was measured at a 45 degrees angle with a crosshead speed of 1mm/min, and the failure patterns were observed. The photoelastic stress distribution of specimens with or without FRC posts was also evaluated. The fracture resistance was analyzed by analysis of variance and a Duncan's multiple range test (p<0.05).
In the no post groups, the fracture resistances decreased significantly in groups with two or fewer walls. The FRC post increased fracture resistances significantly, except for the zero-wall group, and optimized the failure patterns. A high stress concentration was observed along the canal space in the no post groups; stress seemed to be distributed in post groups in photoelasticity.
Within the limitation of the experimental methods of this study, the FRC post was advantageous in lower premolars, especially with two or more walls in terms of the fracture resistance and stress distribution.
本研究比较了 100 个具有不同数量（0-4 个）牙冠壁的模拟下颌前磨牙的抗折强度和破坏模式，有无纤维增强复合材料（FRC）桩。此外，还分析了光弹应力分布。
以 45 度角、十字头速度为 1mm/min 测量抗折强度，观察破坏模式。还评估了有无 FRC 桩的试件的光弹应力分布。采用方差分析和邓肯多重范围检验（p<0.05）对抗折强度进行分析。
在无桩组中，两壁或更少壁的组的抗折强度显著降低。FRC 桩显著提高了抗折强度，除了零壁组，并且优化了破坏模式。无桩组中沿根管空间观察到高的应力集中；光弹性中似乎在桩组中分布了应力。
在本研究的实验方法的限制内，FRC 桩在较低的前磨牙中具有优势，特别是在两个或更多壁的情况下，在抗折强度和应力分布方面。
