BACKGROUND The resin bond strength of sclerotic dentine is significantly lower than that of the normal dentine, which paused a challenge for bonding procedures clinically. The aim of this study was to compare the effects of different surface pretreatments on the micro-tensile bond strength and microstructure between sclerotic dentine and normal dentine. METHODS Eighty teeth that were collected, forty premolars with typical wedge-shaped defects visually graded as class III were assigned as the sclerotic dentine group (SD), the other forty normal premolars with artificial wedge-shaped defects were assigned as the normal dentine group (ND). Each group was randomly subdivided into eight subgroups according to the solution used: 35% phosphoric acid, 15% EDTA, 5% or 10% NaClO. Then the dentine surface was examined using a scanning electron microscope (SEM). The lesions were restored using self-etching adhesive and the subsequent resin composite. The teeth were sectioned into sticks for the micro-tensile bond strength analysis, and the data were analysed using the SPSS17.0 software package (α = 0.05). RESULTS First, for the ND groups, after pretreatment using 35% phosphoric acid, and 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the normal dentine were higher than that of the other groups (P < 0.05). Second, for the SD groups, after pretreatment using 35% phosphoric acid, 15% EDTA, and 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the sclerotic dentine were higher than that of the other groups (P < 0.05). Third, the bond strengths of the sclerotic dentine were lower than that of the normal dentine without any pretreatment (P < 0.05). After pretreatment using 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the sclerotic dentine were higher than that of the normal dentine (P < 0.05). SEM observation showed that the appearances of dentine surface were changed after pretreatment using the above solutions, with the reduced smear layer, opened small groove and increased dentinal tubules. CONCLUSION Pretreatment of dentine using 35% phosphoric acid+ 5% or + 10% sodium hypochlorite changed the microstructure of the sclerotic dentine surface and subsequently increased the micro-tensile bond strength.

中文翻译：

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表面预处理后硬化和正常牙本质之间的微拉伸键强度和微结构差异的比较研究。

背景技术硬化性牙本质的树脂结合强度显着低于正常牙本质的树脂结合强度，这暂停了临床上对结合过程的挑战。这项研究的目的是比较不同表面预处理对硬化性牙本质和正常牙本质之间的微张力结合强度和微观结构的影响。方法收集80颗牙齿，将40个视觉上被分类为III类的典型楔形缺损的前磨牙指定为硬化性牙本质组（SD），将另外40个具有人工楔形缺损的正常前磨牙指定为正常牙本质组（SD）。 ND）。根据使用的溶液，将每组随机分为8个亚组：35％磷酸，15％EDTA，5％或10％NaClO。然后使用扫描电子显微镜（SEM）检查牙本质表面。使用自蚀刻粘合剂和随后的树脂复合物修复损伤。将牙齿切成棒状以进行微拉伸粘结强度分析，并使用SPSS17.0软件包（α= 0.05）分析数据。结果首先，对于ND组，使用35％磷酸和35％磷酸+ 5％或10％次氯酸钠的预处理后，正常牙本质的结合强度高于其他两组（P <0.05） 。其次，对于SD组，在使用35％磷酸，15％EDTA和35％磷酸+ 5％或10％次氯酸钠的预处理后，硬化性牙本质的结合强度高于其他组（P <0.05）。第三，未经任何预处理的硬化性牙本质的结合强度低于正常牙本质的结合强度（P <0.05）。用35％磷酸+ 5％或10％次氯酸钠预处理后，硬化性牙本质的结合强度高于正常牙本质的结合强度（P <0.05）。SEM观察表明，使用上述溶液预处理后，牙本质表面的外观发生了变化，涂片层减少，小槽开口，牙本质小管增加。结论使用35％磷酸+ 5％或+ 10％的次氯酸钠对牙本质进行预处理，改变了硬化性牙本质表面的微观结构，并随后增加了微拉伸粘合强度。用35％磷酸+ 5％或10％次氯酸钠预处理后，硬化性牙本质的结合强度高于正常牙本质的结合强度（P <0.05）。SEM观察表明，使用上述溶液预处理后，牙本质表面的外观发生了变化，涂片层减少，小槽开口，牙本质小管增加。结论使用35％磷酸+ 5％或+ 10％的次氯酸钠对牙本质进行预处理，改变了硬化性牙本质表面的微观结构，并随后增加了微拉伸粘合强度。用35％磷酸+ 5％或10％次氯酸钠预处理后，硬化性牙本质的结合强度高于正常牙本质的结合强度（P <0.05）。SEM观察表明，使用上述溶液预处理后，牙本质表面的外观发生了变化，涂片层减少，小槽开口，牙本质小管增加。结论使用35％磷酸+ 5％或+ 10％的次氯酸钠对牙本质进行预处理，改变了硬化性牙本质表面的微观结构，并随后增加了微拉伸粘合强度。SEM观察表明，使用上述溶液预处理后，牙本质表面的外观发生了变化，涂片层减少，小槽开口，牙本质小管增加。结论使用35％磷酸+ 5％或+ 10％的次氯酸钠对牙本质进行预处理，改变了硬化性牙本质表面的微观结构，并随后增加了微拉伸粘合强度。SEM观察表明，使用上述溶液预处理后，牙本质表面的外观发生了变化，涂片层减少，小槽开口，牙本质小管增加。结论使用35％磷酸+ 5％或+ 10％的次氯酸钠对牙本质进行预处理，改变了硬化性牙本质表面的微观结构，并随后增加了微拉伸粘合强度。