目的是研究用不同的后修复系统修复的根管治疗牙齿的垂直牙根断裂(VRF)抗性和裂纹形成。对相似大小的人类上颌侧切牙进行了装饰,分为五组(n=18,power=0.9),并嵌入带有人工牙周膜的丙烯酸块中。根管充填后,制备柱空间以放置相同形状和尺寸的涂覆的纤维增强复合材料(FRC)或喷砂钛(Ti)柱。一半的柱子是磷酸锌胶结的(C),而另一半被粘附(A)。未治疗的牙齿作为对照。在咀嚼模拟器中进行热循环和楼梯加载后,对牙根牙本质表面的裂纹形成进行了显微检查,并归类为无缺陷,crazeline,垂直裂纹,和水平裂缝。随后,加载样品直到根部断裂。数据采用单因素方差分析,Tukey\'stest,和费希尔的精确检验。所有样本都在没有VRF的咀嚼模拟中幸存下来,但两组间裂纹形成有显著差异(P=0.009)。对照显示出比FRC/C明显更少的缺陷,Ti/C,和Ti/A(分别为P=0.001,P=0.008,P=0.008)。FRC/C显示垂直裂纹的发生率最高。FRC/A的缺陷发生率最低。两组间VRF抵抗无显著差异(P=0.265)。粘附的FRC柱不会增加VRF阻力,但会降低缺陷的风险。大多数缺陷是裂纹线和垂直根部裂纹。
The aim was to investigate the vertical root fracture (VRF) resistance and crack formation of root canal-treated teeth restored with different post-luting systems. Human maxillary lateral incisors of similar size were decoronated, assigned to five groups (n = 18, power = 0.9) and embedded in acrylic blocks with artificial periodontal ligament. After root canal filling, post spaces were prepared to place coated fiber-reinforced composite (FRC) or sandblasted titanium (Ti) posts of the same shape and size. Half of the posts were zinc phosphate cemented (C), while the other half was adhesively luted (A). Untreated teeth served as control. After thermal cycling and staircase loading in a chewing simulator, the crack formation on the root dentin surface was microscopically examined and classified as no defect, craze line, vertical crack, and horizontal crack. Subsequently, the samples were loaded until root fracture. Data were analyzed by one-way ANOVA, Tukey\'s test, and Fisher\'s exact test. All samples survived the chewing simulation without VRF, but crack formation was significantly different between the groups (P = 0.009). The control showed significantly fewer defects than FRC/C, Ti/C, and Ti/A (P = 0.001, P = 0.008, P = 0.008, respectively). FRC/C showed the highest incidence of vertical cracks. FRC/A had the lowest incidence of defects. There was no significant difference in VRF resistance between the groups (P = 0.265). Adhesively luted FRC posts did not increase VRF resistance but reduced the risk of defects. Most defects were craze lines and vertical root cracks.