ABSTRACT
Bonding agents with acceptable mechanical properties are required for a persistent bond between dental composites and tooth substrate. The purpose of this study was to investigate the effects of formulation of the resin on the mechanical properties and bond strength to the enamel. Experimental resins containing Bis-GMA and TEGDMA at the ratios [w/w] of 60/40, 50/50, 40/60 were prepared. Specimens [n=10] were prepared and tested after 24 h exposure to 37°C water for flexural strength [FS], micro-tensile strength [MTS] and micro-shear bond strength [MSBS] to the enamel. A proprietary bonding agent [Heliobond, Ivoclar Vivadent] was used as control. Data were analyzed by one-way ANOVA and Tukey HSD tests [alpha=0. 05]. The results showed that there were significant statistical differences between flexural strength of the adhesives [p<0.05]. The adhesive which contained 60% BisGMA showed the highest flexural strength [57.42 Mpa], while the adhesive containing 40% BisGMA showed the lowest flexural strength [31.82 Mpa]. MTS and MSBS did not differ significantly [p>0.05]. Based on the results of this study, although the content of BisGMA did not affect the microtensile strength and microshear bond strength to the enamel, the flexural strength tended to increase by the increase in BisGMA content