Zhao Qing, Han Fei, Yuan Xiaojun, Chen Chen
Department of Endodontics, The Affiliated Stomatological Hospital of Nanjing Medical University, Jiangsu Province Key Laboratory of Oral Diseases, Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing 210029, China.
Department of Prosthodontics, The Affiliated Stomatological Hospital of Nanjing Medical University, Jiangsu Province Key Laboratory of Oral Diseases, Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing 210029, China.
ACS Omega. 2021 Jul 17;6(29):19183-19193. doi: 10.1021/acsomega.1c02521. eCollection 2021 Jul 27.
This study aimed to investigate the effects of solvents and pH values on the chemical interaction between 10-methacryloyloxydecyl dihydrogen phosphate (MDP) and hydroxyapatite (HAp). The chemical affinity of MDP toward HAp dissolved in different solvents (E-MDP: 10 wt % MDP and 90 wt % ethanol; E-W-MDP: 10 wt % MDP, 75 wt % ethanol, and 15 wt % water; A-W-MDP: 10 wt % MDP, 75 wt % acetone, and 15 wt % water; and E-W-MDP: 10 wt % MDP, 45 wt % ethanol, and 45 wt % water) was investigated. The pH of E-W-MDP was increased from 2.04 to 5 (E-W-MDP) and to 7 (E-W-MDP). The reaction products were characterized by Fourier transform infrared spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and nuclear magnetic resonance (NMR). XRD and NMR results revealed that no MDP-calcium salt formed in E-MDP. XRD, TGA, and XPS results indicated that MDP interacted with HAp, producing the MDP-calcium salt in all groups except E-MDP. NMR results revealed that the dicalcium salt of the MDP dimer (DCS-MD) and the MDP tripolymer (DCS-MT) and the monocalcium salt of the MDP monomer and the MDP dimer were formed in E-W-MDP. DCS-MD and DCS-MT were also formed in E-W-MDP and A-W-MDP. In E-W-MDP and E-W-MDP, DCS-MD was obtained. Both the solvents and pH values affect the chemical interactions between MDP and HAp and the types of reaction products formed. MDP and HAp do not form any MDP-calcium salt in pure ethanol; the structural stability of MDP-calcium salts is dependent on the solvent water content and the pH value. The ethanol/water mixture is recommended as the main solvent in an MDP-containing primer, and the ideal pH value is 2-7; if these conditions are satisfied, sufficient amounts of MDP-calcium salts with stable structures are expected to be formed, thus improving the longevity of dentin/enamel bonding.
本研究旨在探究溶剂和pH值对10 - 甲基丙烯酰氧基癸基磷酸二氢酯（MDP）与羟基磷灰石（HAp）之间化学相互作用的影响。研究了MDP对溶解于不同溶剂中的HAp的化学亲和力（E - MDP：10 wt% MDP和90 wt%乙醇；E - W - MDP：10 wt% MDP、75 wt%乙醇和15 wt%水；A - W - MDP：10 wt% MDP、75 wt%丙酮和15 wt%水；以及E - W - MDP：10 wt% MDP、45 wt%乙醇和45 wt%水）。将E - W - MDP的pH值从2.04分别调至5（E - W - MDP）和7（E - W - MDP）。通过傅里叶变换红外光谱、X射线衍射（XRD）、X射线光电子能谱（XPS）、热重分析（TGA）和核磁共振（NMR）对反应产物进行表征。XRD和NMR结果表明，在E - MDP中未形成MDP - 钙盐。XRD、TGA和XPS结果表明，MDP与HAp相互作用，除E - MDP外，在所有组中均生成了MDP - 钙盐。NMR结果显示，在E - W - MDP中形成了MDP二聚体的二钙盐（DCS - MD）和MDP三聚体（DCS - MT）以及MDP单体和MDP二聚体的单钙盐。在E - W - MDP和A - W - MDP中也形成了DCS - MD和DCS - MT。在E - W - MDP和E - W - MDP中获得了DCS - MD。溶剂和pH值均会影响MDP与HAp之间的化学相互作用以及所形成反应产物的类型。在纯乙醇中，MDP和HAp不会形成任何MDP - 钙盐；MDP - 钙盐的结构稳定性取决于溶剂中的水含量和pH值。建议在含MDP的底漆中使用乙醇/水混合物作为主要溶剂，理想的pH值为2 - 7；如果满足这些条件，预计会形成足够量的结构稳定的MDP - 钙盐，从而提高牙本质/牙釉质粘结的持久性。
