Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8525, Japan.
J Dent Res. 2012 Apr;91(4):376-81. doi: 10.1177/0022034512437375. Epub 2012 Feb 1.
According to the 'Adhesion-Decalcification' concept, specific functional monomers within dental adhesives can ionically interact with hydroxyapatite (HAp). Such ionic bonding has been demonstrated for 10-methacryloyloxydecyl dihydrogen phosphate (MDP) to manifest in the form of self-assembled 'nano-layering'. However, it remained to be explored if such nano-layering also occurs on tooth tissue when commercial MDP-containing adhesives (Clearfil SE Bond, Kuraray; Scotchbond Universal, 3M ESPE) were applied following common clinical application protocols. We therefore characterized adhesive-dentin interfaces chemically, using x-ray diffraction (XRD) and energy-dispersive x-ray spectroscopy (EDS), and ultrastructurally, using (scanning) transmission electron microscopy (TEM/STEM). Both adhesives revealed nano-layering at the adhesive interface, not only within the hybrid layer but also, particularly for Clearfil SE Bond (Kuraray), extending into the adhesive layer. Since such self-assembled nano-layering of two 10-MDP molecules, joined by stable MDP-Ca salt formation, must make the adhesive interface more resistant to biodegradation, it may well explain the documented favorable clinical longevity of bonds produced by 10-MDP-based adhesives.
根据“黏附-脱矿”概念，牙本质黏结剂中的特定功能单体可以与羟磷灰石（HAp）发生离子相互作用。已经证明，10-甲基丙烯酰氧癸基二氢磷酸酯（MDP）以自组装“纳米层”的形式表现出这种离子键合。然而，当商业 MDP 基黏结剂（Clearfil SE Bond，Kuraray； Scotchbond Universal，3M ESPE）按照常见的临床应用方案应用时，这种纳米层是否也会出现在牙本质组织上，仍有待探索。因此，我们使用 X 射线衍射（XRD）和能量色散 X 射线光谱（EDS）从化学角度，以及使用（扫描）透射电子显微镜（TEM/STEM）从超微结构角度对黏结-牙本质界面进行了表征。两种黏结剂均在黏结界面处显示出纳米层，不仅在混合层内，而且特别是对于 Clearfil SE Bond（Kuraray），纳米层延伸到黏结层内。由于这种由两个 10-MDP 分子自组装形成的稳定 MDP-Ca 盐的连接，必然使黏结界面更能抵抗生物降解，这很可能解释了基于 10-MDP 的黏结剂所产生的粘结的良好临床耐久性。
