title: Alkaline nanoparticle coatings improve resin bonding of 10-methacryloyloxydecyldihydrogenphosphate-conditioned zirconia.
abstract: Creating an alkaline environment prior to 10-methacryloyloxydecyldihydrogenphosphate (MDP) conditioning improves the resin bonding of zirconia. The present study evaluated the effects of four alkaline coatings with different water solubilities and pH values on resin bonding of MDP-conditioned zirconia. Two alkaline nanoparticle coatings were studied in particular. Thermodynamics calculations were performed to evaluate the strengths of MDP-tetragonal phase zirconia chemical bonds at different pH values. Zirconia surfaces with and without alkaline coatings were characterized by scanning electron microscope (SEM)/energy dispersive spectrometer and Fourier transform infrared spectroscopy; alkaline coatings included NaOH, Ca(OH)2, nano-MgO, and nano-Zr(OH)4. A shear bond strength (SBS) test was performed to evaluate the effects of the four alkaline coatings on bonding; the alkaline coatings were applied to the surfaces prior to conditioning the zirconia with MDP-containing primers. Gibbs free energies of the MDP-tetragonal zirconia crystal model coordination reaction in different pH environments were -583.892 (NaOH), -569.048 [Ca(OH)2], -547.393 (MgO), and -530.279 kJ/mol [Zr(OH)4]. Thermodynamic calculations indicated that the alkaline coatings improved bonding in the following order: NaOH > Ca(OH)2> MgO > Zr(OH)4. Statistical analysis of SBS tests showed a different result. SBSs were significantly different in groups that had different alkaline coatings, but it was not influenced by different primers. All four alkaline coatings increased SBS compared to control groups. Of the four coatings, nano-Zr(OH)4and -MgO showed higher SBS. Therefore, preparing nano-Zr(OH)4or -MgO coatings prior to conditioning with MDP-containing primers may potentially improve resin bonding of zirconia in the clinic.
authors: Department of Prosthodontics.
authors: Mengke
authors: M
authors: Qian
authors: Department of Prosthodontics.
authors: Zhicen
authors: Z
authors: Lu
authors: Department of Endodontics, Jiangsu Key Laboratory of Oral Diseases, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, People's Republic of China.
authors: Chen
authors: C
authors: Chen
authors: Department of Prosthodontics.
authors: Huaiqin
authors: H
authors: Zhang
authors: Department of Prosthodontics.
authors: Haifeng
authors: H
authors: Xie
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D001840:Dental Bonding; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000468:Alkalies; D020099:Coated Materials, Biocompatible; D008689:Methacrylates; D019279:Resin Cements; D015040:Zirconium; C028541:zirconium oxide
keywords: MDP; T-YZP; adhesion; bond strength; surface conditioning; zirconia primer