目的

构建牙本质混合层原位再矿化诱导模型，并从微观形态学角度探讨其矿化效果，为仿生再矿化技术的临床应用提供实验依据。

方法

采用5 mm×5 mm Ⅰ型胶原海绵块作为3D胶原支架，结合电镜观察和傅里叶红外光谱分析技术，快速评估成核诱导物多聚磷酸钠（STTP）和硅酸盐水门汀树脂的仿生矿化诱导潜能。 在此基础上，将仿生矿化技术与牙本质粘接程序结合，以STTP作为治疗性底剂应用于酸蚀脱矿牙本质面，在完成常规粘接处理后以硅酸盐水门汀树脂为洞衬剂，构建临床相关的混合层原位再矿化模型。 采用透射电子显微镜观察矿化1 ～3 个月后树脂牙本质粘接界面再矿化区域的分布和再矿化程度。

结果

矿化诱导28 d 后的3D 胶原样本，纤维内可见磷灰石纳米晶体的有序沉积，纤维重现了与天然矿化胶原结构类似的横纹特征。 红外光谱分析结果显示，在900 ～1200 cm^-1 和500 ～600 cm^-1 区域，矿化胶原基质出现与纯羟基磷灰石特征峰相吻合的吸收峰，提示矿化胶原中形成的无机物是磷灰石。 混合层原位矿化诱导1 ～3 个月后，混合层内可见纤维内再矿化现象的存在，纳米晶体在胶原纤维内呈现迭序排列特征。

结论

在牙体粘接修复过程中，以矿化诱导物STTP 和硅酸盐水门汀树脂作为治疗性底剂和洞衬剂，能使混合层内树脂渗透不良的胶原基质发生纤维内矿化。 通过混合层原位再矿化模型的成功构建，初步证实仿生矿化技术应用于临床树脂牙本质粘接界面损伤修复的可行性，建立了研究方法学，为仿生再矿化技术的最终临床应用提供充分的科学依据。

Objective

To test the hypothesis that the application of asodium tripolyphosphate（STTP） primer and a Portland cement-based lining composite on hybrid layers can induce intrafibrillar remineralization in the presence of the amorphous calcium phosphate （ACP）-stabilization analog supplied in simulated body fluid （SBF）.

Methods

Together with Portland cement-based composite， biomimetic remineralization system was built by phosphorylating collagen with 0.245 mol/L STTP for 5 min and by adding polyacrylic acid （PAA） to SBF. Based on these results， a in-situ mineralization scheme was developed for chemical phosphorylation of acid-etched dentin with 0.245 mol/L STTP， followed by infiltration of the STTP-treated collagen matrix with One-Step. Resin dentin interfaces were then capped with a Portland cement-based hydrophilic composite a liner， and remineralized in SBF with the use of PAA as an ACP-stabilization analog. Remineralized resin-dentin interfaces were examined unstained using transmission electron microscopy （TEM）.

Results

Periodic nanocomposite assembly with collagen sponge as a template was demonstrated with TEM using a Portland cement-based resin composite and a 5-minute STTP phosphorylation. Apatite was detected within the collagen at 72 h， and heavily deposited in collagen fibrils with periodically arranged intrafibrillar apatite platelets at 28 d. Infrared spectrum of the mineralized collagen sponge demonstrated characteristic hydroxyl apatite peaks at 900 ～1200 cm ^-1 and 500 ～600 cm^-1. The results of that model were further validated by complete remineralization of the hybrid layers treated with 0.245 mol/L STTP as a therapeutic primer and lined with a Portland cementbased lining composite， and with the ACP-stabilization analog supplied in SBF.

Conclusions

The STTP primer and the Portland cement-based lining composite employed in this study may be used with the ACP-stabilization analogy for in-situ remineralization of hybrid layer. This provides a potential delivery system for realization of the goal of biomimetic remineralization of dentin hybrid layer.