International Journal of Nanomedicine (Jul 2016)
Sol–gel dip coating of yttria-stabilized tetragonal zirconia dental ceramic by aluminosilicate nanocomposite as a novel technique to improve the bonding of veneering porcelain
Abstract
Azamsadat Madani,1 Mohammadreza Nakhaei,2 Parisa Karami,3 Ghadir Rajabzadeh,4 Sahar Salehi,4,5 Hossein Bagheri6 1Dental Research Center, Department of Prosthodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, 2Dental Materials Research Center, Department of Prosthodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, 3Department of Prosthodontics, Faculty of Dentistry, Zanjan University of Medical Sciences, Zanjan, 4Department of Nanotechnology, Research Institute of Food Science and Technology, Mashhad, 5Department of Material and Metallurgical Engineering, University of Semnan, Semnan, 6Dental Materials Research Center, Department of Operative Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran Abstract: The aim of this in vitro study was to evaluate the effect of silica and aluminosilicate nanocomposite coating of zirconia-based dental ceramic by a sol–gel dip-coating technique on the bond strength of veneering porcelain to the yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) in vitro. Thirty Y-TZP blocks (10 mm ×10 mm ×3 mm) were prepared and were assigned to four experimental groups (n=10/group): C, without any further surface treatment as the control group; S, sandblasted using 110 µm alumina powder; Si, silica sol dip coating + calcination; and Si/Al, aluminosilicate sol dip coating + calcination. After preparing Y-TZP samples, a 3 mm thick layer of the recommended porcelain was fired on the coated Y-TZP surface. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis were used to characterize the coating and the nature of the bonding between the coating and zirconia. To examine the zirconia–porcelain bond strength, a microtensile bond strength (µTBS) approach was chosen. FT-IR study showed the formation of silica and aluminosilicate materials. XRD pattern showed the formation of new phases consisting of Si, Al, and Zr in coated samples. SEM showed the formation of a uniform coating on Y-TZP samples. Maximum µTBS values were obtained in aluminosilicate samples, which were significantly increased compared to control and sandblasted groups (P=0.013 and P<0.001, respectively). This study showed that aluminosilicate sol–gel dip coating can be considered as a convenient, less expensive reliable method for improving the bond strength between dental Y-TZP ceramics and veneering porcelain. Keywords: dip coating, zirconia, porcelain, bond strength
