Oper Dent. 2020 Sep 1;45(5):556-566. doi: 10.2341/19-165-L.
The degree of conversion of contemporary universal adhesives positively correlates with the bond strength to dentin. The correlation is more marked after thermocycling, suggesting that a high degree of conversion is required for long-term dentin bonding durability.
Purpose: The objectives of this study were to evaluate the micro-tensile bond strength (μTBS) of five contemporary universal adhesives to dentin after 24 hours and thermocycling (TC), to measure their degrees of conversion (DC) and to test the correlation between μTBS and DC.Methods and Materials: Four commercially available universal adhesives, Prime&Bond universal (PBU), Ecosite Bond (EB), G-Premio Bond (GPB), and Clearfil Universal Bond Quick (UBQ), and one experimental adhesive, UBQ without an amide monomer (UBQ-A), were used in this study. For the μTBS test, midcoronal dentin of 50 human molars was exposed, ground using 600-grit SiC paper, and the adhesives were applied according to the manufacturers' instructions. After resin-composite buildup and 24-hour water storage, one-half of the specimens were subjected to 15,000 thermal cycles. The specimens were sectioned into beams and stressed in tension at a crosshead speed of 1 mm/min until failure. The DC of adhesives applied to dentin was evaluated using attenuated total reflectance Fourier-transform infrared spectroscopy immediately after light-curing. All data were statistically analyzed at a significance level of 0.05.Results: The highest μTBSs were obtained with UBQ, UBQ-A, and PBU, which were not significantly different from each other both after 24 hours and TC. The μTBS of GPB was lower compared with the aforementioned adhesives, but significantly only after TC, and the lowest μTBSs were obtained with EB. TC did not affect the μTBSs of UBQ, UBQ-A, and PBU significantly, but a significant decrease was observed with GPB and EB. The highest DC was obtained with PBU and UBQ, followed by 2-hydroxyethyl methacrylate-rich adhesives UBQ-A and EB, which exhibited significantly lower DCs. The DC of GPB could not be determined because the reference peak at 1608 cm-1 was not detected in its spectra. A significant positive correlation was shown between μTBS and DC after 24 hours (r=0.716) and TC (r=0.856).Conclusion: μTBS and DC were positively correlated, more markedly after TC, which suggests that DC may be an important factor for bond durability.
当代通用型胶粘剂的转化率与牙本质的粘结强度呈正相关。热循环后相关性更明显，表明长期牙本质粘结耐久性需要高转化率。
目的：本研究的目的是评估五种通用型胶粘剂在 24 小时和热循环后（TC）对牙本质的微拉伸粘结强度（μTBS），测量其转化率（DC），并测试 μTBS 与 DC 之间的相关性。
本研究使用了四种市售的通用型胶粘剂，分别是 Prime&Bond universal（PBU）、Ecosite Bond（EB）、G-Premio Bond（GPB）和 Clearfil Universal Bond Quick（UBQ），以及一种实验性的胶粘剂 UBQ 无酰胺单体（UBQ-A）。对于 μTBS 测试，使用 50 个人类磨牙的中冠部牙本质，用 600 目 SiC 砂纸打磨，按照制造商的说明涂敷胶粘剂。树脂复合材料堆积后，水储存 24 小时，一半的标本进行 15000 次热循环。将标本切成梁状，在十字头速度为 1mm/min 的情况下进行拉伸，直至破坏。在光固化后立即使用衰减全反射傅里叶变换红外光谱法评估涂在牙本质上的胶粘剂的 DC。所有数据均在 0.05 的显著水平上进行统计分析。
在 24 小时和 TC 后，UBQ、UBQ-A 和 PBU 的 μTBS 最高，彼此之间没有显著差异。GPB 的 μTBS 低于上述胶粘剂，但仅在 TC 后有显著差异，而 EB 的 μTBS 最低。TC 对 UBQ、UBQ-A 和 PBU 的 μTBS 没有显著影响，但对 GPB 和 EB 的 μTBS 有显著降低。PBU 和 UBQ 的 DC 最高，其次是富含 2-羟乙基甲基丙烯酸酯的胶粘剂 UBQ-A 和 EB，其 DC 明显较低。GPB 的 DC 无法确定，因为其光谱中未检测到 1608cm-1 的参考峰。24 小时后（r=0.716）和 TC 后（r=0.856），μTBS 与 DC 呈显著正相关。
μTBS 和 DC 呈正相关，TC 后相关性更明显，这表明 DC 可能是粘结耐久性的一个重要因素。
