Dental Biomaterials Dep., Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
Dental Biomaterials Dep., Faculty of Oral and Dental Medicine, Zagazig University, Zagazig, Egypt.
J Mech Behav Biomed Mater. 2021 Sep;121:104590. doi: 10.1016/j.jmbbm.2021.104590. Epub 2021 May 19.
Treatment the deeper and remineralizable carious zone (DRCZ) in dentin with various remineralizing methods, either with classic top-down or biomimetic bottom-up remineralization approaches, has remained a constant main issue to enhance dentin substrate bonding quality. The concern of remineralizing the remaining, partially demineralized and physiologically re-mineralizable collagen fibrils was the optimum target. However, applying already mineralized type I collage fibrils which have the ability to chemically cross-link with remaining collagen and minerals did not gain much interest. Synthesis of collagen/hydroxyapatite (Col/Hap) nanocomposite was done with self-assembling Hap in situ onto Col fibrils with different % (70/30, 50/50, 30/70% of Col/Hap, respectively). Micro-tensile bond strength (μTBS) was evaluated after pre-treatment of artificially demineralized dentin with these suggested protocols [nanocomposite together with grape seed extract (GSE; 6.5%) cross-linker for two periods, 10min and 1 h] then applying self-adhesive bonding system. Applied Col/Hap (30/70%) together with GSE (6.5%) gave the significantly highest μTBS (25.04 ± 5.47 and 25.53 ± 7.64 MPa, for 10min and 1 h application times, respectively). After thermocycling for 10,000 cycles at 5 and 55 °C, μTBS for all protocols and both application times substantially decreased especially for the two control groups. Using the suggested dentin pre-treatment protocols, in chair-side, may possibly enhance the bond strength to DRCZ and its durability.
用各种再矿化方法治疗牙本质的更深和可再矿化的龋坏区（DRCZ），无论是经典的自上而下还是仿生的自下而上的再矿化方法，一直是提高牙本质基质粘结质量的主要问题。再矿化剩余的、部分脱矿和生理上可再矿化的胶原纤维的关注点是最佳目标。然而，应用已经矿化的 I 型胶原纤维，其具有与剩余的胶原和矿物质化学交联的能力，并没有引起太多的兴趣。通过在 Col 纤维上原位自组装 Hap，合成了 Col/羟基磷灰石（Col/Hap）纳米复合材料，Col/Hap 的比例分别为 70/30、50/50、30/70%。在用这些建议的方案（纳米复合材料与葡萄籽提取物（GSE；6.5%）交联剂一起预处理人工脱矿牙本质两个周期，10min 和 1h）后，评估了微拉伸粘结强度（μTBS），然后应用自粘结粘结系统。应用 Col/Hap（30/70%）与 GSE（6.5%）一起，给出了明显最高的 μTBS（25.04±5.47 和 25.53±7.64MPa，分别为 10min 和 1h 的应用时间）。在 5 和 55°C 下进行 10000 次热循环后，所有方案和两种应用时间的 μTBS 都显著降低，特别是对于两个对照组。在椅旁使用建议的牙本质预处理方案，可能会增强对 DRCZ 的粘结强度及其耐久性。
