مرکز منطقه ای اطلاع رساني علوم و فناوري - Evaluation of microhardness and Bis-GMA release of a new composite restorative material

Abstract :

OBJECTIVE: The aim of this study is to compare the microhardness, the degree of conversion and the elution of Bis-GMA of a new microhybrid composite for posterior restoration with a commonly used microhybrid composite material. MATERIALS AND METHOD: In this study, a newly manufactured composite resin material with a microhybrid filler content (NOVA Compo-HS, Imicryl, Konya, Turkey) and another commercially available composite resin material containing microhybrid filler (Filtek Z-250, 3M ESPE, St. Paul, MN, USA) were used. 20 samples of each material were prepared in cylindrical form (2x2x2 mm). The amount of the eluted Bis-GMA from ten of the 20 samples for each material was analyzed by high performance liquid chromatography (HPLC) (Shimadzu, Model SPD 20A, Shimadzu Corporation, Kyoto, Japan). The Vickers surface microhardness of the other remaining ten of 20 samples for each material was measured and the polymerization depth was evaluated by calculating the Vickers hardness ratio. The statistical analysis was performed with two independent samples t-test. RESULTS: There were differences between NOVA Compo-HS and Filtek Z250 in hardness values recorded on the upper and lower surfaces (p 0.001). The amount of eluted Bis-GMA monomer from NOVA Compo-HS and Filtek Z250 was 1.28 mg/L and 0.78 mg/L. There was a statistically difference between the groups (p 0.001). CONCLUSION: NOVA Compo-HS, a new composite resin material with microfiller, was not found as sufficient as the other microfiller composite for the mechanical properties (surface microhardness and the ratio of bottom/top surface hardness values). The amount of eluted Bis-GMA monomers was higher in the NOVA Compo-HS composite than the Filtek Z250.