Cytotoxicity evaluation of new resin matrix system on fiber-reinforced composites

Abstract

PURPOSE: Recent commercial resin matrix systems use bis-GMA as the basic matrix. A previous studies showed that bis-GMA affected the vitality of dental pulp and induced pulpal inflammation (Engelmann J, et al. Biomaterials 2004;25:4573), was able to disturb normal differentiation procedures of pulp fibroblasts (Imazato S, et al. J Biomed Mater Res Part B: Appl Biomater 2009;88B:378), and induced allergic contact stomatitis (Stoeva et al. J IMAB-Ann Proc 2008;book 2:45). A monomer alternative to bis-GMA, such as 1,6-hexanediol dimethacrylate (HDMA), is under current research. The purpose of this study was to determine the cytotoxicity property of HDMA on fibroblast cells by MTT method. METHODS AND MATERIALS: The materials used were bis-GMA (Sigma–Aldrich, USA), MMA (ProSciTech, Australia), HDMA (Esstech, USA), CQ (Esstech, USA), CEMA (Esstech, USA), Eglass fibers (Stick Tech, Finland), Vero fibroblast cell line (UGM, Indonesia). Fifteen specimens of FRCs (2×2×25)mm were prepared and divided into 3 groups. The experiment groups were 78.4%HDMA +19.6%MMA+ 1.0%CQ + 1.0%CEMA (Exp-1 group) and 49.0%HDMA +49.0%MMA+ 1.0%CQ + 1.0%CEMA Exp-2 group), whilst the control group was 78.4%bis-GMA+19.6%MMA+ 1.0%CQ + 1.0%CEMA. Specimens were milled and diluted in culture medium (0.1mg powder/1mL medium). Specimen solution of 100µL was added into 96-well plate containing fibroblast cells of 2×104 cells/100µL and incubated for 24 h. MTT of 10µL was added to the well, incubated for 4h, then 100µL stop solution was added. The OD of the cells viability was determined by a ELISA reader with a wavelength of 550 nm. Cells viability was calculated in percentage and analyzed by ANOVA and LSD. RESULTS: Analysis by one way ANOVA revealed significant differences of cells viability among the groups (p < 0.01). The LSD test showed a significant difference between exp-1 group and control group and also between exp-2 group and control group (p < 0.01), whilst no significant difference between exp-1 group and exp-2 group was found (p > 0.05). CONCLUSION: A resin matrix system based on HDMA–MMA (exp-1 group and exp-2 group) revealed a significant difference of fibroblast cells viability compared to a bis-GMA–MMA matrix system. The HDMA–MMA matrix systemwas less cytotoxic than bis-GMA–MMA matrix system.