Department of Operative and Esthetic Dentistry, Faculty of Dentistry, University of Szeged, Szeged, Hungary.
dicomLAB Dental Ltd., Szeged, Hungary.
Dent Mater. 2021 Mar;37(3):391-402. doi: 10.1016/j.dental.2020.11.026. Epub 2021 Jan 19.
The aim was to investigate the fatigue survival and marginal-gap inside the root-canal of endodontically treated (ET) premolars reinforced by various fiber-reinforced post-core composites (FRCs). Moreover, composite-curing at different depths in the canal was evaluated.
170 intact upper-premolars were collected and randomly divided into ten groups (n = 15). One group served as control (intact-teeth). After endodontic procedure standard MO cavities were prepared and restored with different post-core fiber-reinforced materials and designs. Three-group (A1-A3) were restored with either packable and flowable short fiber-reinforced composite (SFRC) core or conventional composite-core. Two-group (B1-B2) were restored with SFRCs as short post (3 mm) and core. Four-group (C1-C4) were restored with SFRCs as post (6 mm) and core with or without unidirectional FRC posts (individually-made or conventional). After completing the restorations, teeth from Group C1-C4 (n = 5/group) were sectioned and stained. Specimens were viewed under a stereo-microscope and the percentage of microgaps within the root-canal was calculated. Fatigue-survival was measured using a cyclic-loading machine in the rest of the specimens.
Application of flowable SFRC as luting-core material with individually-made FRC post (Group C3) did not differ from intact-teeth regarding fatigue-survival (p > 0.05). The rest of the groups produced significantly lower survival (p < 0.05) compared to intact-teeth. Post/core restorations made from packable SFRC (Group C1) had a lower microgap (19.1%) at the examined interphase in the root-canal than other groups.
The restoration of ET premolars with the use of individually-made FRC post and SFRC as luting-core material showed promising achievement regarding fatigue-resistance and survival.
研究不同纤维增强型桩核复合材料（FRC）增强的根管内牙本质的疲劳生存和边缘间隙。此外，还评估了在根管内不同深度进行的复合固化。
收集 170 颗完整的上颌前磨牙，随机分为十组（n = 15）。一组作为对照组（完整牙）。经过根管治疗程序，制备标准 MO 腔，并使用不同的桩核纤维增强材料和设计进行修复。三组（A1-A3）分别用可压实和可流动的短纤维增强复合材料（SFRC）核或常规复合核修复。两组（B1-B2）用 SFRC 作为短桩（3 毫米）和核修复。四组（C1-C4）用 SFRC 作为桩（6 毫米）和核修复，有或没有单向 FRC 桩（单独制作或常规）。完成修复后，将来自 C1-C4 组的牙齿（n = 5/组）进行切割和染色。在立体显微镜下观察标本，并计算根管内的微间隙百分比。其余标本在循环加载机上进行疲劳生存测试。
使用单独制作的 FRC 桩作为流动 SFRC 核（组 C3）的应用在疲劳生存方面与完整牙无差异（p > 0.05）。其余组的生存情况明显低于完整牙（p < 0.05）。用可压实 SFRC 制作的桩核修复（组 C1）在根管内的检查界面处具有较低的微间隙（19.1%）。
使用单独制作的 FRC 桩和 SFRC 作为核材料修复根管内的 ET 前磨牙，在抗疲劳性和生存方面显示出有前途的效果。
