Chemical Bond of Silane Coupling Agents to Reinforced Porcelains

Objectives: The purpose of this study was to evaluate the bond strength between polymer cements and porcelain structures by chemical means of silane coupling
Methods: 40 samples, 5x10 mm of porcelains, Emax Press and Emax CAD lithium disilicate based and ZirCAD zirconia based (Ivoclar Vivadent) were sinterized following manufacturer’s instructions before being imbibed in acrylic and then polished with 600 grit SiC paper under water. Each group was divided into 4 sub-groups of 10 specimens each to receive silanes: Monobond (Ivoclar/Vivadent), Silane (Ultradent Prods), Bis Silane (BISCO) y Clearfil Ceramic Primer (Kuraray), all following manufacturer’s instructions.
2 mm diameter prefabricated composite cilinders (Brilliant, Coltene) were roughened and cemented on each sample with Variolink II (Ivoclar Vivadent) after a previous coat of Tetric N-Bond (Ivoclar Vivadent), applying a 500gr force and eliminating excess before light curing. 24 hrs. after all specimens were made; they were tested in shear at 0.1 cm/min speed until failure. Data were stored in MPa and analyzed with a two-way ANOVA and means were compared with Tukey-Kramer test, both calculated at a 0.05 significance level. Extra set of specimens was made to analyze its surfaces with Raman spectroscopy and SEM.
Results: Means and standard deviation in MPa are shown on table.
Clearfil CP showed a statistically significant higher bond strength than other silanes for ZirCAD and EmaxCAD. None silane showed a statistical higher bond strength on EmaxPress
Conclusions: Silane chemical bond to zirconia is weaker than lithium disilicate; different silanes produce variations on the chemical bonding between ceramics and organic resin cements