Microtensile bond strength to a glass ceramic and properties of experimental resin cements containing a diphenyliodonium derived salt

Abstract

The aim of this study will be to evaluate the properties of experimental resin cements (ERCs) containing different concentrations of Diphenyliodonium Hexafluorphosphate (DPIHFP) salt, as well as the immediate and one year after storage bond strength to a lithium disilicate ceramic. For this purpose, five ERCs will be prepared using a Bis-GMA/TEGDMA (1:1 molar ratio) base compound and different DPIHFP concentrations of 0, 0.25, 0.5, 1 or 2 mol% added to this compound. For the microtensile bond strength test, 84 blocks of IPS E.max Press ceramic (Ivoclar Vivadent, Schaan, Liechtenstein; 10 mm x 10 mm wide x 3 mm thick) will be made according to the manufacture's advice. Microhybrid composite resin blocks (10 mm x 10 mm wide x 5 mm thick) will be fixed to the ceramic blocks under a 500g static load for one minute and the light activation will be performed through the ceramic, for 1 minute, with a LED source Bluephase G2(Ivoclar Vivadent, Schaan, Liechtenstein). After the microtensile bond strength tests (immediate an after one year), the failure mode of the specimens will be analyzed by a stereomicroscope (Leica MZ75) at 40x magnification and one example of each type of failure mode will be made in scanning electron microscopy. In addition, it will be performed the ultimate microtensile strength of ERCs using hourglass specimens. Also, degree of conversion measure by Fourier transform infrared spectroscopy (Spectrum 100 Optica; PerkinElmer, MA, USA) and water sorption and solubility test will be performed at ERCs disc shape specimens. The values of each test will be tabulated and submitted to an appropriate statistical test. (AU)