Department of Clinical Sciences - Restorative, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
Department of Clinical Sciences - Restorative, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada; Department of Prosthodontics, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
Dent Mater. 2018 Nov;34(11):1625-1633. doi: 10.1016/j.dental.2018.08.297. Epub 2018 Sep 7.
We investigated the biostability of dentin organic matrices treated with epigallocatechin gallate (EGCG) in comparison to chlorhexidine (CHX), both extracted from functionalized copolymers.
Copolymers were prepared with bis-GMA:TEGDMA and incorporated with 1% of EGCG or CHX (w/w). Blank copolymers were used as control. Copolymer samples were individually stored in 1mL deionized water to produce copolymer extracts. Dentin matrices were obtained by demineralization of dentin disks in 10% phosphoric acid solution. Matrices were individually treated with 1mL of the copolymer extracts or distilled water for 48h. Collected extracts were analyzed by high-performance liquid chromatography (HPLC) for the presence and quantification of EGCG, CHX, and copolymer by-products. Treated dentin matrices were tested for ultimate tensile strength, gravimetric changes, and swelling ratio. The treatment media were tested for total protein concentration, and dentin protease activity through solubilized telopeptide (ICTP- and CTX-ELISA) assays. The treatment media were also submitted to proteomic analysis.
HPLC identified released unreacted copolymer species and showed higher release of CHX compared to EGCG from respective copolymer extracts. EGCG extract inhibited activity of dentin proteolytic enzymes and promoted collagen biomodification observed by the telopeptide assays and in the changes to dentin matrix properties. The proteomic results showed less collagenous peptide hits in the EGCG extract media compared to CHX, and suggest compound-specific dentin protein binding interactions.
This study demonstrates specific antiproteolytic effect and protein interactions of EGCG copolymer extract directly on dentin. This represents an advancement in dental materials which can impact the clinical procedures.
我们研究了从功能化共聚物中提取的表没食子儿茶素没食子酸酯（EGCG）和洗必泰（CHX）处理牙本质有机基质的生物稳定性。
采用双甲基丙烯酸甘油酯：三乙二醇二甲基丙烯酸酯合成共聚物，并分别掺入 1%的 EGCG 或 CHX（w/w）。空白共聚物用作对照。将共聚体样品单独储存在 1ml 去离子水中以产生共聚体提取物。通过将牙本质圆盘在 10%磷酸溶液中脱矿质来获得牙本质基质。将基质分别用 1ml 共聚体提取物或蒸馏水处理 48 小时。通过高效液相色谱法（HPLC）分析收集的提取物，以检测 EGCG、CHX 和共聚体副产物的存在和定量。对处理后的牙本质基质进行极限拉伸强度、重量变化和溶胀率测试。对处理介质进行总蛋白浓度测试，并通过可溶的末端肽（ICTP 和 CTX-ELISA）测定法测试牙本质蛋白酶活性。还对处理介质进行了蛋白质组学分析。
HPLC 鉴定出释放的未反应共聚体物质，并显示出从相应的共聚体提取物中释放出的 CHX 比 EGCG 更高。EGCG 提取物抑制牙本质蛋白水解酶的活性，并通过末端肽测定法和牙本质基质性质的变化来促进胶原蛋白的生物修饰。蛋白质组学结果表明，与 CHX 相比，EGCG 提取物介质中胶原肽的命中数较少，并且表明化合物特异性的牙本质蛋白结合相互作用。
本研究证明了 EGCG 共聚体提取物对牙本质具有直接的特定抗蛋白水解作用和蛋白质相互作用。这代表了牙科材料的进步，可以影响临床程序。
