Department of Restorative Dentistry and Endodontics, Research Center TADERP, Faculty of Dentistry, "Victor Babeș" U.M.Ph.-Timisoara, 300041 Timisoara, Romania.
Faculty of Dentistry, "Victor Babeș" U.M.Ph.-Timisoara, 300041 Timisoara, Romania.
Medicina (Kaunas). 2023 Oct 9;59(10):1797. doi: 10.3390/medicina59101797.
Although fiber posts are widely used in the restoration of endodontically treated teeth (ETT), their ideal cementation depth into the root canal is still debated in literature. The aim of the present study was to evaluate whether the different intra-radicular insertion lengths of the fiber posts influence the fracture strength of ETT. A total of 10 permanent human lower incisors with straight roots of similar length and volume extracted for periodontal reason were sectioned 2 mm above the cement-enamel junction (CEJ) to a total length of 18 mm and endodontically treated in the same manner, then randomly divided into two groups of five each (Groups 1 and 2, = 5). Two sound incisors, with no endodontic treatment, were used as the control group (Group 3, = 2). After one week of storage in a humid environment, spaces for fiber post no. 1 (Reforpost, Angelus, Londrina, PR, Brazil) were prepared in the first two groups at a depth of 5 mm (Group 1) and 7 mm (Group 2), and the fiber posts were adhesively cemented using self-adhesive resin cement (Maxcem Elite, Kerr GmbH, Herzogenrath, Germany). After 7 days, the samples were vertically positioned and fixed in a self-curing transparent acrylic resin, up to 2 mm below the CEJ level, and mechanically tested in compression after another week of storage using a displacement-controlled testing machine up to each sample's fracture. The force-displacement curves were recorded for each sample, the means were calculated for each group and a statistical comparative analysis between groups was conducted. Although no statistically significant differences between groups were observed, the highest mean fracture force (N) was recorded in Group 2 (1099.41 ± 481.89) in comparison to Group 1 (985.09 ± 330.28), even when compared to the sound, non-treated teeth (1045.69 ± 146.19). Within the limitations of this in vitro study, teeth where fiber posts were placed deeper into the root canal (7 mm) recorded slightly higher fracture forces in comparison with shorter lengths (5 mm). However, similar biomechanical performances obtained in the mechanical tests showed no statistical differences between the 7 mm and the 5 mm inserted posts.
尽管纤维桩在根管治疗牙（ETT）的修复中被广泛应用，但它们在根管内的理想粘结深度在文献中仍存在争议。本研究旨在评估纤维桩的不同根管内插入长度是否会影响 ETT 的断裂强度。
总共从因牙周原因而拔出的 10 颗具有相似长度和体积的直根的人恒下前牙中，每颗牙在釉牙骨质界（CEJ）上方 2mm 处截断，总长度为 18mm，并以相同的方式进行根管治疗，然后随机分为两组，每组 5 颗牙（组 1 和组 2，n=5）。另外 2 颗未经根管治疗的健康切牙作为对照组（组 3，n=2）。在潮湿环境中储存一周后，在第一组和第二组制备纤维桩 1 号（Reforpost，Angelus，Londrina，PR，巴西）的空间，深度为 5mm（组 1）和 7mm（组 2），并使用自粘结树脂粘结剂（Maxcem Elite，Kerr GmbH，Herzogenrath，德国）将纤维桩粘结。7 天后，将样本垂直定位并固定在自固化透明丙烯酸树脂中，低于 CEJ 水平 2mm，在另一个星期的储存后，使用位移控制试验机以每个样本的断裂为基础对其进行机械压缩测试。记录每个样本的力-位移曲线，计算每组的平均值，并对组间进行统计比较分析。
虽然组间没有观察到统计学上的显著差异，但与组 1（985.09±330.28）相比，组 2（1099.41±481.89）的平均断裂力（N）最高，甚至与未经处理的健康牙齿（1045.69±146.19）相比也是如此。
在这项体外研究的限制范围内，纤维桩在根管内插入更深（7mm）的牙齿记录的断裂力略高于插入较短长度（5mm）的牙齿。然而，机械测试中获得的类似生物力学性能显示，7mm 和 5mm 插入的纤维桩之间没有统计学差异。
