Abstract

This study aimed to evaluate the influence of cement type and mechanical cycling on the push-out bond strength (σ) of fiber posts luted to root canals. Eighty bovine single-root teeth were prepared and the roots were included with chemically cured acrylic resin. The specimens were allocated into 8 groups (n = 10) considering the factors ‘cement’ (glass ionomer cement – GIC, resin reinforced glass ionomer cement – RRGIC, conventional dual-cure resin cement – CRC, and self-adhesive resin cement – SARC) and ‘mechanical cycling’ (non-aged and aged – mc). The fiber posts and roots dentin were treated according to the cement type and luted to root canals. Composite-cores were made for the groups submitted to mechanical cycling (1,000,000 cycles, 84 N, 4 Hz). Each root were cut into 4 disk-samples of 1.8 mm (thickness) and submitted to push-out testing. Data (MPa) were analyzed using two-way ANOVA, Tukey test (5%), and Weibull analysis. ANOVA revealed that cement (p < 0.001) was significant; however, the mechanical cycling had no effect on bond strength (p = 0.895). The CRC (4.36 ± 1.15 MPa), CRCmc (4.13 ± 0.75 MPa), GIC (4.29 ± 2.14 MPa), and GICmc (4.04 ± 1.18 MPa) groups showed higher (σ) than RRGIC (2.36 ± 1.00 MPa). Weibull Characteristic strength of the CRC and CRCmc were significantly higher than RRGICmc, and RRGIC. The mixed type of failure was the most common. Conventional dual-cure resin cement and glass ionomer cement presented higher push-out bond strength to root dentin regardless of mechanical cycling.

摘要

本研究旨在评估水泥类型和机械循环对固定到根管的纤维桩的推出粘合强度 ( σ ) 的影响。制备了 80 颗牛单根牙齿，并用化学固化的丙烯酸树脂将牙根包括在内。将标本分为 8 组（n = 10) 考虑因素“水泥”（玻璃离子水门汀 – GIC、树脂增强玻璃离子水门汀 – RRGIC、传统双固化树脂水泥 – CRC 和自粘树脂水泥 – SARC）和“机械循环”（非老化和老化 - mc）。纤维桩和根牙本质根据水泥类型进行处理并固定到根管中。为接受机械循环（1,000,000 次循环，84 N，4 Hz）的组制作复合芯。每个根被切成 4 个 1.8 毫米（厚度）的圆盘样品并进行推出测试。数据 (MPa) 使用双向 ANOVA、Tukey 检验 (5%) 和 Weibull 分析进行分析。ANOVA 显示水泥 ( p  < 0.001) 显着；然而，机械循环对粘合强度没有影响（p = 0.895）。CRC (4.36 ± 1.15 MPa)、CRCmc (4.13 ± 0.75 MPa)、GIC (4.29 ± 2.14 MPa) 和 GICmc (4.04 ± 1.18 MPa) 组的 ( σ ) 高于 RRGIC (2.36 ± 1.00 MPa)。CRC 和 CRCmc 的 Weibull 特征强度显着高于 RRGICmc 和 RRGIC。混合型故障是最常见的。无论机械循环如何，传统的双固化树脂粘固剂和玻璃离子粘固剂对牙根的推出粘合强度更高。