表没食子儿没食子酸酯对牙本质基质拼接面的生物改性作用

Sun Qiurong, Gu Lisha, Wu Shiyu, Huang Zihua, Mai Sui

Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University & Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China.

Zhonghua Kou Qiang Yi Xue Za Zhi. 2016 Mar;51(3):148-53. doi: 10.3760/cma.j.issn.1002-0098.2016.03.005.

OBJECTIVE

To investigate the effect of epigallocatechin-3-gallate (EGCG) on biomodification of demineralized dentine substrate, in its permeability, hydrophobicity, and inhibition ability to collagen enzymatic degradation.

METHODS

The dentine substrates were treated with simulated pulpal pressure created by mixtures of 0.02%, 0.1% EGCG/bovine serum albumin (BSA) in acidic environment (pH4.4) for 48 h. A fluid-transport model was used to measure the fluid permeability through demineralized dentine substrate. Positive replicas of dentine substrate were fabricated before and after being subjected to acidic environment for scanning electron microscope (SEM) examination. The blank group contained no EGCG and the positive group were treated with Gluma desensitizer. Static contact angle measurements on demineralized dentin and 0.1% EGCG primed dentin were performed by contact angle analyzer. The priming time were 60 s, 120 s, 0.5 h, 1 h. Dentine specimens bonded with Adper single bond 2 were subjected to 100 mg/L collagenase and observed under SEM. Resin-bonded specimens (with 0.02%, 0.1%, 0.5% EGCG priming, or without EGCG priming) were created for micro-tensile bond strength evaluation (MTBS). Resin-bonded specimens after thermol cycling were created for MTBS evaluation.

RESULTS

The fluid permeability in the blank control group increased ([151.3±22.3]%), the fluid permeability in 0.1% EGCG/BSA group decreased ([23.7±6.3]%). Compared to the blank control group, the contact angle of 120 s, 0.5 h, 1 h groups increased by 31.0%, 53.5%, 57.8% in deep dentin and 37.4%, 59.3%, 62.4% in shallow dentin. The SEM examination showed that 0.1% and 0.5% EGCG priming for 120 s significantly increased dentin collagen's resistance to collagenase. The immediate MTBS of 0.1% and 0.5% EGCG groups were (29.4±4.8) and (19.8± 4.9) MPa. After thermol cycling, the MTBS of 0.1% and 0.5% EGCG groups were (19.9±5.1) and (15.3± 6.3) MPa.

CONCLUSIONS

Under acidic environment (pH4.4), the 0.1% EGCG can reduce dentine permeability under acidic environment. The 0.1% EGCG can increase hydrophobicity of dentin substrate, and strengthen dentin substrate's resistance to collagenase hydrolysis, thus increased the resin-dentin bonding durability.

目的

研究表没食子儿茶素-3-没食子酸酯（EGCG）对脱矿牙本质基质生物改性的影响，包括其渗透性、疏水性以及对胶原酶降解的抑制能力。

方法

在酸性环境（pH4.4）中，用0.02%、0.1%的EGCG/牛血清白蛋白（BSA）混合物产生模拟牙髓压力处理牙本质基质48小时。采用流体传输模型测量脱矿牙本质基质的流体渗透性。在牙本质基质经受酸性环境前后制作正性复制品，用于扫描电子显微镜（SEM）检查。空白组不含EGCG，阳性组用Gluma脱敏剂处理。通过接触角分析仪测量脱矿牙本质和用0.1%EGCG预处理的牙本质的静态接触角。预处理时间分别为60秒、120秒、0.5小时、1小时。用Adper单组分粘结剂2粘结的牙本质标本用100mg/L胶原酶处理，并在SEM下观察。制作树脂粘结标本（用0.02%、0.1%、0.5%EGCG预处理或未用EGCG预处理）用于微拉伸粘结强度评估（MTBS）。制作热循环后的树脂粘结标本用于MTBS评估。

结果

空白对照组的流体渗透性增加（[151.3±22.3]%），0.1%EGCG/BSA组的流体渗透性降低（[23.7±6.3]%）。与空白对照组相比，120秒组、0.5小时组、1小时组在深层牙本质中的接触角分别增加31.0%、53.5%、57.8%，在浅层牙本质中分别增加37.4%、59.3%、62.4%。SEM检查显示，0.1%和0.5%EGCG预处理120秒可显著提高牙本质胶原对胶原酶的抗性。0.1%和0.5%EGCG组的即时MTBS分别为（29.4±4.8）和（19.8±4.9）MPa。热循环后，0.1%和0.5%EGCG组的MTBS分别为（19.9±5.1）和（15.3±6.3）MPa。