Influence of the type of silane prior to the use of a universal adhesive on lithium disilicate

Silanes and universal adhesives are alternatives for chemical adhesion to ceramics. These materials may share some components, so it is worth studying their performance and synergy. The objective of this study was to compare the association of a universal adhesive with two types of silane on lithium disilicate. Lithium disilicate sheets were made by lost-wax method and divided into 5 groups: silane, silane with phosphate monomers (MDP), universal adhesive, silane + universal adhesive and silane with MDP + universal adhesive. The ceramic was previously etched with hydrofluoric acid in all groups. Ten composite resin cylinders of 0.75mm diameter were attached for each group, the samples were stored 90 days in distilled water at 37C. A micro-shear test was performed by pulling with a wire loop. The highest values of the study were obtained by the groups where silanes were used prior to the universal adhesive. Within the limitations of this study, it was concluded that the application of a silane followed by a universal adhesive is essential. Silane with MDP appears to be less efficient compared to a silane without this monomer in promoting chemical adhesion to lithium disilicate (LDS).