Biomaterials, Biomimetics and Biophotonics B3, King's College London Dental Institute, Guy's Dental Hospital, London, UK.
J Biomater Sci Polym Ed. 2013;24(8):940-56. doi: 10.1080/09205063.2012.727377. Epub 2012 Oct 1.
This study aimed at evaluating the therapeutic remineralising effects of innovative light-curable materials (LCMs) containing two experimental calcium silicate-based micro-fillers (TCS) modified with β-TCP only or β-TCP, zinc oxide (ZnO)/polyacrylic acid (PAA) on mineral-depleted bonded-dentine interfaces in simulated body fluids (SBFS). Three experimental LCMs were formulated: (1) resin A, containing a β-TCP-modified TCS (βTCS) micro-filler; (2) resin B, containing a polycarboxylated β-TCP/ZnO-modified TCS (βZn-TCS) micro-filler; and 3) resin C, containing no filler (control). Acid-etched (35% H3PO4) dentine specimens were bonded using the three LCMs and submitted to atomic force microscope (AFM)/nano-indentation analysis to evaluate the modulus of elasticity (Ei) and hardness (Hi) across the interface after SBFS storage (24 h/1 m/3 m). The ultramorphology and micropermeability of the resin-dentine interface were evaluated using confocal laser microscopy. Resin-dentine sticks were created and submitted to microtensile bond strength (μTBS) test (SBFS: 24 h/3 m). Scanning electron microscopy (SEM) was performed after de-bonding. The LCMs containing the experimental bioactive micro-fillers reduced the micropermeability and induced a significant increase of the Ei and Hi along the bonding interface. The specimens created using the resin B (βZn-TCS) attained the highest μTBS values both after 24 h and 3 m of SBFS storage. In conclusion, the innovative bioactive light-curable materials tested in this study are able to induce a therapeutic remineralising effect on the nano-mechanical properties and on the sealing ability of mineral-depleted resin-dentine interfaces. The contemporary idea of minimally invasive operative treatment, where therapeutic restorations are performed to combat the carious process and remineralise the dental hard tissues, may be satisfied by using such resin-base systems, containing βTCS or βZn-TCS bioactive micro-fillers.
本研究旨在评估含有两种实验性硅酸钙基微填料（TCS）的新型光固化材料（LCM）的治疗再矿化效果，这两种微填料分别经β-TCP 改性（仅含β-TCP）或β-TCP、氧化锌（ZnO）/聚丙烯酸（PAA）改性，用于模拟体液（SBFS）中脱矿粘结牙本质界面。本研究制备了三种实验性 LCM：（1）树脂 A，含经β-TCP 改性的 TCS（βTCS）微填料；（2）树脂 B，含经多羧基化β-TCP/ZnO 改性的 TCS（βZn-TCS）微填料；（3）树脂 C，不含填料（对照）。采用三种 LCM 酸蚀（35% H3PO4）牙本质试件，进行原子力显微镜（AFM）/纳米压痕分析，评估 SBFS 储存（24 h/1 m/3 m）后界面的弹性模量（Ei）和硬度（Hi）。采用共聚焦激光显微镜评估树脂-牙本质界面的超微形态和微渗透性。制作树脂-牙本质棒，进行微拉伸粘结强度（μTBS）测试（SBFS：24 h/3 m）。随后进行去粘结，采用扫描电子显微镜（SEM）进行检测。含有实验性生物活性微填料的 LCM 降低了微渗透性，并沿粘结界面显著提高了 Ei 和 Hi。在 SBFS 储存 24 h 和 3 m 后，使用树脂 B（βZn-TCS）制作的试件获得了最高的 μTBS 值。总之，本研究中测试的新型生物活性光固化材料能够对纳米力学性能和脱矿树脂-牙本质界面的密封能力产生治疗再矿化作用。使用这种含有βTCS 或βZn-TCS 生物活性微填料的树脂基系统进行微创治疗操作的当代理念，可以满足治疗修复以对抗龋齿过程和再矿化牙体硬组织的需求。
