Approach of an experimental resin cement containing a diphenyliodonium salt evaluating the influence of different tertiary amines and the microtensile bond strength to glass ceramic

Abstract

The aim of this study will be to evaluate the bond strength of experimental resin cements containing different concentrations of diphenyliodonium salt in its formulation to a lithium disilicate reinforced ceramic and the influence of two tertiary amines (added in its formulation) on the properties of these same experimental cements. A model Bis-GMA/TEGDMA comonomer blend (1:1 molar ratio) was obtained and DPI added at concentrations of 0 (control), 0.25, 0.5, 1 and 2 mol% resulting in five experimental resin cements. The photoinitiator system was composed of 1 mol% of camphorquinone and 2 mol% of dimethylaminoethyl methacrylate. 0.1 mol% of hydroxyl butyl toluene was used as an inhibitor and the cements were loaded with a 60% mass fraction of silanated Ba-Al-Si glass fillers. Lithium disilicate ceramic (e.max, Ivoclar Vivadent, Schaan, Liechtenstein) rectangular blocks will be made following the manufacturer's recommendations measuring 3mm x 10 mm x 6 mm of high, wide and thick respectively in order to cure the cement through ceramic. A light-cured resin Filtek Supreme XT (3M ESPE) measuring 5 mm x 10 mm x 6 mm will be used as basis for the procedure and the blocks will be made with a polyvinyl siloxane matrix measuring 10 mm x 10 mm x 6 mm. After the microtensile test, it will be analyzed the pattern of fractures and the values will be tabulated and submited to an appropriate statistical test. Ethyl 4-dimethylamino benzoate EDMAB and dimethylaminoethyl methacrylate (DMAEMA) will be evaluated in the following concentrations: 0% DFI G1 with 0.5% DMAEMA, G2 0% 1% DMAEMA with DFI,% DFI with G3 0 0 5% EDMAB, G4 0% to 1% EDMAB DFI,% DFI 0.5 G5 with 0.5% DMAEMA, G6 0.5% to 1% DMAEMA DFI, DFI G7 0.5% to 0.5% EDMAB , G8 0.5% to 1% EDMAB DFI, DFI G9 1% to 0.5% DMAEMA, G10 1% 1% DFI with DMAEMA, G11 1% to 0.5% EDMAB DFI, DFI G12 1% 1% EDMAB. Each test will have a specimen size according to protocol. The specimens will be made to perform the following tests: degree of conversion (5 mm x 0,5 mm), flexural strength modulus(6,5mm × 2 mm × 1 mm), water sorption and solubility (6mm x 1 mm). The results will be statistically analyzed for each of the tests. (AU)