ABSTRACT
Tabassom Hooshmand a,∗, Alireza Keshvad b and Richard van Noort c a Department of Dental Materials, School of Dentistry/Research Center for Science and Technology
in Medicine, Tehran University of Medical Sciences, Ghods Street, Tehran 14174, Iran b Department of Prosthodontics, School of Dentistry, University of Shahed, Italia Street,
Tehran 14317, Iran c Department of Adult Dental Care, School of Clinical Dentistry, University of Sheffield,
Claremont Crescent, Sheffield S10 2TA, UK
Abstract This study was designed to investigate the surface properties and the thickness of organofunctional silane films formed on leucite-reinforced feldspathic (LRF) ceramic surfaces after different methods of silane application using X-ray photoelectron spectroscopy (XPS). Six LRF ceramic discs (Mirage®, Myron Intl., Kansas City, KS, USA) were produced according to the manufacturer’s instructions and polished to a 1 µm finish. A silane coupling agent was applied to five ceramic discs using different application methods: (A) immersion in silane solution for 60 s and dried with compressed air spray for 15 s; (B) as method A but heat treated with hot air at 50 ± 5◦C for 15 s; (C) silane was applied with a brush for 60 s and dried with compressed air spray for 15 s; (D) as method C but heat treated with hot air at 50±5◦C for 15 s; (E) as method C followed by rinsing the specimens with hot water (15 s) and drying with hot air for 30 s. The ceramic surfaces were then analyzed by XPS at 15◦–60◦ take-off angles. The results showed the highest and the lowest increase of C1s (C in the structure of silane) for treatments A and E, respectively. Signals of COO or C-COO in the high resolution spectra of C1s were observed for all silane-treated ceramic surfaces. The proportion of C-Si groups on the silane-treated surfaces compared with the untreated surface was significantly increased. XPS analysis indicates that the thickness of the silane film on a leucite-reinforced feldspathic ceramic surface is a function of the mode of application. The lowest film thickness of silane was found for treatment E, which more closely matches that of a monolayer.
