title: Composition, reactivity and surface interactions of three dental silane primers.
abstract: Three commercially available dental silane primers, two single-phase prehydrolyzed and one two-component system were investigated for their composition, extent of hydrolysis, surface interactions, bond strength and interfacial topography when used on three representative porcelain alloys (Au-Pd, high-Pd, Ni-Cr). Five tests, 1H FT-NMR, FTIR, GPC, ESCA and EPMA, were used to determine the composition and the surface interaction profiles. Shear tests were performed to assess the bond strength values. According to the results, all the primers contain gamma-methacryloxypropyltrimethoxysilane (gamma-MPTS) at concentrations of 1.15-18.86 g/100 mL, two in ethanol and one in isopropanol. Traces of acetic acid were found in the prehydrolyzed primers. All the primers demonstrated partial hydrolysis of the methoxy groups. Prehydrolyzed primers exhibited a higher rate of hydrolysis and better orientation of hydrolyzed methoxy groups towards the Ni-Cr alloy surface. Due to the extent of surface oxidation, the Ni-Cr alloy provided more bonding sites for silanols than the other two types of alloys. The Ni-Cr alloy demonstrated the highest shear bond strength values on smooth surfaces regardless of the type of primer used. The results of the present study suggest that active prepolymerized primers may provide significant advantages over two-component systems in the repair of Ni-Cr porcelain fractures involving removal of the metal oxide layer.
authors.forename: T
authors.initials: T
authors.lastname: Anagnostopoulos
authors.forename: G
authors.initials: G
authors.lastname: Eliades
authors.forename: G
authors.initials: G
authors.lastname: Palaghias
mesh_terms: D000704:Analysis of Variance; D002858:Chromium Alloys; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D017269:Dental Prosthesis Repair; D003801:Dental Veneers; D004577:Electron Probe Microanalysis; D006047:Gold Alloys; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D009532:Nickel; D010165:Palladium; D012044:Regression Analysis; D019279:Resin Cements; D012821:Silanes / Q000737:chemistry*; D012826:Silicone Elastomers / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013329:Structure-Activity Relationship; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D002858:Chromium Alloys; D003188:Composite Resins; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D008689:Methacrylates; D019279:Resin Cements; D012821:Silanes; D012826:Silicone Elastomers; C082343:silanol; C061501:Scotchprime; C017492:methacryloxypropyltrimethoxysilane; D010165:Palladium; D009532:Nickel