Mechanical and Anti-bacterial Properties of Dental Adhesive Containing Diamond Nanoparticles

The effect of nanoparticle diamond incorporated in an experimental dentaladhesive formulation is evaluated by examining the mechanical propertiesand shear bond strength of the system. Diamond nanoparticles were incorporatedinto the dentin adhesive system in different concentrations of 0, 0.05, 0.1,0.2, 0.5, and 1.0 weight percentages. The suspensions were ultrasonicated to facilitatethe nano-particle dispersion in an adhesive solution containing ethanol, bis-GMA,UDMA, TMPTMA, HEMA and photo-initiator system. Diametral tensile strength,flexural strength, flexural modulus, depth of cure and microshear bond strength of theadhesive system were measured. The adhesive-dentin interface was then observed byscanning electron microscopy. The results were analyzed using one-way ANOVA ata significant level of P>0.05. No significant difference was observed between the diametral tensile strength of the adhesive. At nanoparticle content level of 0.1% (by wt),however, 85% increase in flexural strength and 13% enhancement in flexural moduluswere observed. Microshear bond strength test revealed 70% and 79% improvementsof adhesion force in systems containing 0.1% and 0.2% nanoparticles, respectively.Although the neat diamond nanoparticles revealed antibacterial activity, the adhesivecontaining different percentages of the nano particles did not show any antibacterialactivities when tested against, Staphilococcus Aureus, Staphilococcus Streptococcus,Staphilococcus ephidermidis, Saprophyticus, Enterococcus faecalis bacteries