Statement of problem

The limited durability of resin-dentin bonds is considered a major disadvantage of adhesive restorations. Therefore, clinical strategies have been developed to improve hybrid layer stability over time. These strategies require testing.

Purpose

The purpose of this in vitro study was to evaluate the influence of preheating and the inclusion of a bioactive glass in a unidose 3-step etch-and-rinse adhesive system on the adhesion of direct composite resin restorations.

Material and methods

Dentin disks from 80 molars were assigned to 8 groups (n=10): CG-T1/CG-T2: control group; PG-T1/PG-T2: adhesive preheated to 68 °C; BG-T1/BG-T2: 0.05 mg of Bioglass 45S5 (BAG) (particle size: 3 μm) added to primer; PBG-T1/PBG-T2: adhesive and BAG-modified primer preheated to 68 °C. Sticks were fabricated for microtensile bond strength (μTBS) testing and were tested at 1 week (T1) and after 6 months (T2) of storage. μTBS data were analyzed by using 2-way ANOVA and the Tukey-Kramer post hoc test (α=.05). Scanning electron microscopy was used to analyze the failure mode. Attenuated total reflection Fourier transform infrared spectroscopy was used to quantitatively analyze the modifications to the chemical structure of the adhesive system from preheating and BAG inclusion.

Results

The mean bond strength values at 1 week were statistically different, with PG-T1 (69.8 ±7.8 MPa) superior to all other groups. CG-T1 (58.2 ±6.7 MPa), BG-T1 (60.7 ±4.4 MPa), and PBG-T1 (61.0 ±4.6 MPa) were not statistically different (P>.05). PG-T2 maintained the highest bond strength at 6 months (68.3 ±3.7 MPa), with no decrease in μTBS observed over time. Failure modes were mostly adhesive. Attenuated total reflection Fourier transform infrared spectroscopy analysis reported that primer preheating caused solvent evaporation and revealed that preheating the bonding agent promoted the condensation reaction between the silane and adhesive fillers.

Conclusions

No decrease in μTBS was observed for any group after 6 months. Preheating the adhesive system (primer and bonding resin) significantly increased the 1-week and 6-month μTBS. Inclusion of BAG did not affect the bond strength.

中文翻译：

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热和生物活性优化的单剂量三步蚀刻和冲洗牙本质粘合剂。

问题陈述

树脂-牙本质键的有限耐久性被认为是粘合剂修复的主要缺点。因此，已经开发出临床策略来改善混合层随时间的稳定性。这些策略需要测试。

目的

这项体外研究的目的是评估预加热以及在单剂量3步蚀刻和冲洗粘合系统中加入生物活性玻璃对直接复合树脂修复体粘合的影响。

材料与方法

将来自80颗磨牙的牙本质牙盘分为8组（n = 10）：CG-T1 / CG-T2：对照组； d-对照组。PG-T1 / PG-T2：粘合剂预热至68°C；BG-T1 / BG-T2：将0.05 mg Bioglass 45S5（BAG）（粒径：3μm）添加到底漆中; PBG-T1 / PBG-T2：粘合剂和经BAG改性的底漆预热至68°C。制备棒以进行微拉伸粘合强度（μTBS）测试，并在储存1周（T1）和6个月（T2）后进行测试。使用2通方差分析和Tukey-Kramer事后检验（α= .05）分析μTBS数据。使用扫描电子显微镜分析故障模式。使用衰减全反射傅里叶变换红外光谱法定量分析了预热和BAG夹杂对胶粘剂体系化学结构的影响。

结果

1周时的平均粘结强度值在统计学上有所不同，其中PG-T1（69.8±7.8 MPa）优于所有其他组。CG-T1（58.2±6.7 MPa），BG-T1（60.7±4.4 MPa）和PBG-T1（61.0±4.6 MPa）在统计学上没有差异（P > .05）。PG-T2在6个月内保持了最高的粘结强度（68.3±3.7 MPa），但未观察到μTBS随时间下降。失效模式主要是粘性的。衰减全反射傅里叶变换红外光谱分析报告说，底漆预热会导致溶剂蒸发，并显示预热粘合剂会促进硅烷与粘合剂填料之间的缩合反应。

结论

6个月后任何组均未观察到μTBS降低。预热粘合剂体系（底漆和粘结树脂）会显着增加1周和6个月的μTBS。包含BAG不会影响粘结强度。