Effectiveness of pre-silanization in improving bond performance of universal adhesives or self-adhesive resin cements to silica-based ceramics: Chemical and in vitro evidences

•Self-condensation of silane consumes the active silane in multipurpose products.•Reaction between silane and 10-MDP consumes active silane in multipurpose products.•Pre-silanization enhances bond improvement of multipurpose products to glass ceramic. To examine effectiveness of pre-silanization in improving bond performance of multipurpose products such as universal adhesives or self-adhesive resin cements to silica-based ceramics. The present study investigated reactions between silanol groups of γ-methacryloxypropyltrimethoxysilane (γ-MPS) and silica, dehydration self-condensation of γ-MPS, and condensation polymerization between γ-MPS and 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) by using thermodynamic calculations. Shear bond strength (SBS) tests were used to evaluate the influence of pre-silanization on resin bonding when a silane-containing universal adhesive, a silane-unknown universal adhesive, or two self-adhesive resin cements were applied for bonding lithium disilicate to resin. In addition, reactions between silane and lithium disilicate were analyzed using X-ray photoelectric spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Acquired thermodynamic data indicated formation of siloxane between γ-MPS and silica. However, self-condensation of γ-MPS and reaction between γ-MPS and 10-MDP consumed the silanol. Pre-silanization enhanced SBS for self-adhesive resin cements or universal adhesives when applied for bonding silica-based ceramics. Thermocycling and aging decreased SBS in most groups. XPS and FTIR supported formation of siloxane between the employed silane coupling agent and two universal adhesives and lithium disilicate. Pre-silanization is beneficial in further enhancing bond performance of universal adhesives or self-adhesive resin cements to silica-based ceramics.