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

Abstract

A B S T R A C T T he effect of nanoparticle diamond incorporated in an experimental dental adhesive formulation is evaluated by examining the mechanical properties and shear bond strength of the system. Diamond nanoparticles were incor- porated into 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 facilitate the 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 the adhesive system were measured. The adhesive-dentin interface was then observed by scanning electron microscopy. The results were analyzed using one-way ANOVA at a significant level of P>0.05. No significant difference was observed between the di- ametral 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 modulus were observed. Microshear bond strength test revealed 70% and 79% improvements of adhesion force in systems containing 0.1% and 0.2% nanoparticles, respectively. Although the neat diamond nanoparticles revealed antibacterial activity, the adhesive containing different percentages of the nano particles did not show any antibacterial activities when tested against, Staphilococcus Aureus, Staphilococcus Streptococcus, Staphilococcus ephidermidis, Saprophyticus, Enterococcus faecalis bacteries.