Silane coupling agents are routinely used to improve adhesion of inorganic particles to the polymer matrix in resin composites. In resorbable resin composites for bone surgery, the silanization of bioactive glass fillers enhances mechanical properties before leaching begins. This study aimed to characterize the physicochemical and biological effects of silanization on bioactive glass S53P4 (BG) using three γ-MPS concentrations (3-(methacryloyloxy)propyltrimethoxysilane).

The starting solution for silanization consisted of 95 % ethanol (pH 4.5, adjusted with acetic acid). Different γ-MPS concentrations (1, 1.5 and 2 %) were obtained by diluting γ-MPS in the starting solution and used to treat micro-sized BG particles. Physicochemical characterizations were performed using ATR-FTIR and SEM. Particles were dissolved in cell culture medium for 7 days and during the dissolution period, the pH change of medium was continuously measured, and quantity of released Si ions was measured at the end. Biocompatibility of γ-MPS treated BG particles was assessed using MC3T3-E1 pre-osteoblastic cells.

During dissolution, the pH varied slightly between the γ-MPS treated and untreated BG, although at the end point of the dissolution period no differences were observed in Si ion release (∼55 mg/L for all groups). No differences were observed in in vitro biomineralization of BG surfaces after γ-MPS treatment. Furthermore, γ-MPS treatment of BG did not influence viability of pre-osteoblastic cells (p > 0.05).

Silanization of BG particles with γ-MPS allowed in vitro biomineralization, indicating bioactivity. Biological in vitro tests with pre-osteoblastic cells showed good cell viability in both γ-MPS treated and untreated BG groups.