properties of dental adhesives incorporated with boehmite nano-particles

the incorporation of boehmite nano-particles and its effects on the mechanical properties and bond strength of an experimental dental adhesive were studied.an adhesive solution containing ethanol, bis-gma, tmptma, hema and photo-initiator system (camphorquinone and dmaema) was prepared. silanized boehmite nano-particles were incorporated into the adhesive in different concentrations of 0, 0.2, 0.5, 1, 2, and 5 weight percentages. the suspensions were ultrasonocated to facilitate the nano-particle dispersion. degree of conversion of the adhesive under visible light irradiation was determined using ft-ir spectroscopy. depth of cure, diametral tensile strength, flexural strength, and micro-shear bond strength of the adhesives were measured. scanning electron electron microscopy was utilized to observe the fracture surface topography. the results were compared using one-way anovaand tukey posthoc test at the significance level of 0.05. the results indicated that the diametral tensile strength, flexural strength, and micro-shear bond strength increased at nano-particle contents of 0.2-0.5 wt.% and beyond this range  there was a declining trend (p<0.05) observed in all these properties because of the nano-particle agglomeration.  no significant difference was observed in flexural moduli of the adhesives with different filler contents. the study revealed that the incorporation of boehmite nanoparticles may improve the properties of dental adhesives.