Degree of Conversion, Bond Strength and Biocompatibility of the APTES@SiO2 Strengthened Experimental Dental Adhesive

The aim of this study was to investigate the effect of incorporation of the nano silica modified with (3-aminopropyl)triethoxysilane (APTES@SiO 2 ) on the degree of conversion, bond strength and biocompatibility of an experimental dental adhesive.An amphiphilic bonding system was used as the experimental dentin bonding system.The APTES@SiO 2 with diameter of 70 nm was prepared and added into the experimental dentin bonding system as nanofiller, and the effect of the modification on the stability of the nano APTES@SiO 2 dispersed in the experimental adhesive was studied.In addition, the morphology, degree of conversion, bond strength to dental restorative resin and biocompatibility of the experimental adhesives containing nanofiller were tested.After modification, the dispersion stability of the nano particles in the adhesive was improved.With increasing the content of the nano APTES@SiO 2 , the rate of light conversion increased significantly.However, the ultimate degree of conversion, bond strength to resin and bulk compressive strength was not significantly affected.Compared with the adhesive without nanofiller, the adhesive with 2 wt% APTES@SiO 2 showed better bond strength to dentin and lower polymerization shrinkage.In addition, the experimental adhesive showed slight cytotoxicity with the incorporation of APTES@SiO 2 , but it was attenuated at low concentration.