Mandava Jyothi, Pamidimukkala Sahithi, Karumuri Srujana, Ravi Ravichandra, Borugadda Roopesh, Afraaz Abdul
Department of Conservative Dentistry and Endodontics, Gandhi Institute of Technology and Management (GITAM) Dental College and Hospital, Visakhapatnam, IND.
Cureus. 2020 Apr 4;12(4):e7536. doi: 10.7759/cureus.7536.
Background To obtain prolonged clinical success with composite restorations, better bonding of resin to the tooth substrate is crucial. Aim The study was aimed to evaluate the microtensile bond strength (µTBS) of bulk-fill composite resin restorations when bonded to a cavity previously restored with amalgam, comparing with that of freshly prepared dentin. Materials and method Mesio-occlusal cavity preparations were done on 80 extracted human mandibular molars with a buccolingual width of 4 mm and a 1.5 mm axial depth by placing the gingival seat 0.5 mm coronal to the cementoenamel junction (CEJ) and were restored with fine-grain amalgam alloy. After thermocycling, the amalgam restorations were removed. Disto-occlusal cavities with similar dimensions of mesial cavities were prepared, and both the proximal surfaces were filled with bulk-fill composite using either etch-and-rinse or self-etch adhesives. Following thermomechanical cyclic loading, all the teeth were sectioned for µTBS testing. Bond strength data expressed in megapascals (MPa) were subjected to statistical analyses using analysis of variance (ANOVA) and Tukey's multiple post-hoc tests. Results The total-etch adhesive exhibited statistically higher bond strength values to both dentin substrates compared to self-etch adhesives (p<0.05). Failure mode analysis reported more of adhesive failures. Conclusion The µTBS of bulk-fill composite resin restorations bonded to a cavity previously restored with amalgam was significantly lower than that of freshly prepared dentin. Total-etch adhesives bond strength was higher than self-etch adhesives to both the substrates tested.
背景 为了使复合树脂修复体获得长期的临床成功，树脂与牙齿基质更好的粘结至关重要。目的 本研究旨在评估大块充填复合树脂修复体粘结到先前用汞合金修复的窝洞时的微拉伸粘结强度（µTBS），并与新鲜制备的牙本质进行比较。材料与方法 在80颗拔除的人类下颌磨牙上制备近中咬合面窝洞，颊舌宽度为4mm，轴向深度为1.5mm，龈壁位于牙骨质釉质界（CEJ）冠方0.5mm处，并用细粒度汞合金修复。热循环后，去除汞合金修复体。制备尺寸与近中窝洞相似的远中咬合面窝洞，近中面均使用酸蚀冲洗或自酸蚀粘结剂充填大块充填复合树脂。经过热机械循环加载后，将所有牙齿切片进行µTBS测试。以兆帕（MPa）表示的粘结强度数据采用方差分析（ANOVA）和Tukey多重事后检验进行统计分析。结果 与自酸蚀粘结剂相比，全酸蚀粘结剂对两种牙本质基质的粘结强度值在统计学上更高（p<0.05）。失败模式分析显示更多的是粘结失败。结论 大块充填复合树脂修复体粘结到先前用汞合金修复的窝洞时的µTBS显著低于新鲜制备的牙本质。在测试的两种基质上，全酸蚀粘结剂的粘结强度均高于自酸蚀粘结剂。
