This study was carried out to prepare an experimental dental adhesive as well as to evaluate the effect of addition of silicone dioxide nanoparticles on its microtensile bond strength (µTBS), viscosity and degree of conversion (DC).Samples were divided into five groups (1, 2, 3, 4 and 5) according to the material used: Group 1; experimentally prepared unfilled adhesive, Group 2; experimentally prepared adhesive filled with 0.1 wt% nano-silica, Group 3; experimentally prepared adhesive filled with 0.5 wt% nano-silica, Group 4; experimentally prepared adhesive filled with 1 wt% nano-silica, Group 5 (control); a commercially available adhesive "Solobond M, Voco, Germany".A volume of 16 ml of unfilled adhesive resin was prepared for each of the four experimental groups, to suffice the experimental testing. Steps of preparation of the experimental adhesive resin in this study involved preparation of the mixture of monomers, preparation of the photo-initiator system and addition of acetone and ethanol solvents.Silicon dioxide nanoparticles were added to the experimentally prepared unfilled adhesive resin in three different concentrations; 0.1, 0.5 and 1 wt%. These nanoparticles were silanized prior to addition to the experimental adhesive resin using the hydrolyzed trimethoxysilane as a silane coupling agent. Furthermore, the silanization process of silica nanoparticles as well as their chemical analysis; before and after silanization were evaluated by transmission electron microscopy (TEM) and Fourier Transform Infrared (FTIR) spectroscopy, respectively.Chemical analysis of the experimentally prepared unfilled adhesive and the commercially available adhesive (Solobond M) was carried out by means of FTIR spectroscopy. Evaluation of the experimental adhesives involved measuring their degree of conversion, viscosity and their dentin microtensile bond strength.Results of the DC revealed that all the four experimental adhesives had a higher mean DC (P ≤ 0.05) compared to that of the commercial control one. Pair-wise comparisons by Duncan's Multiple Range Test between the groups revealed that the experimentally prepared adhesive filled with 0.5 wt% nano-silica (group 3) had the highest DC (30.677%) with a statistically significant difference compared to the other tested groups. The average viscosity of the five tested groups ranged from 0.1471 Pa• s. to 0.0456 Pa• s. Results of the µTBS test revealed that group 4 had the highest µTBS (34.134 MPa) with a statistically significant difference. Results of the chemical analysis revealed a similarity in the chemical composition of both the experimentally prepared unfilled adhesive and the control group. Regarding the silanization process of silica nanoparticles, TEM micrographs revealed that the silanized nanosilica appeared as evenly dispersed slightly apart nanoparticles. FTIR spectra revealed an increased intensity of the Si–O functional group.