Thermal, mechanical, and biocompatibility properties of cured multi-methacrylates derived from propoxylated, enzyme oligomerized BPA neat resins

In a previous study, we showed that the methacrylate derivatives of propoxy lated bisphenol-A oligomers (EPBPA) have potential application for formulat ing visible light-curable (VLC)composites for dental restoratives. The purp ose of this study was to evaluate the thermal, mechanical and biocompatibil ity properties of the EPBPA oligomers. The EPBPA oligomer multi-methacrylat e: triethylene glycol dimethacrylate (TEGDMA) (50:50/wt:wt) blends were com bined with 0.5 wt% camphorquinone (CQ) and 1.0 wt% N,N-di-methyl-aminoethyl methacrylate (DMAEMA). The control was 2,2-bis[4-(2-hydroxy-3-methacryloyl oxpoxy) phenyl] propane (BisGMA:TEGDMA) (50:50/wt:wt) blends having the sam e levels of CQ/DMAEMA. The glass transition temperature (T-g) and the therm al expansion coefficient (alpha) were obtained for all materials studies, u sing a thermomechanical analyzer (TMA, TA Instruments 2940 with an expansio n probe (heating rate 10 degrees C/min, N-2). The compressive (CS) and diam etral tensile strength(DTS) tests were carried out using a screw-driven mec hanical testing machine (Model 4204 screw-driven mechanical testing machine (Model 4204, Instron Corp., Canton, MA) at 25 degrees C, with a constant c rosshead speed of 0.5 mm/min. The biocompatibility test of the polymerized oligomers (EPBPA) was done, and compared with the conventional BisGMA/ TEGD MA neat resins and blank controls, using cellculture techniques. Human ging ival fibroblasts were used for the initial evaluation of the biocompatibili ty of the EPBPA based resins. One-way ANOVA and Tukey multiple comparison (p < 0.05) results show that th e cured EPBPA neat resins have better thermal and mechanical properties tha n the BisGMA/TEGDMA neat resin control. The results also revealed that the EPBPA oligomer significantly favored the cell growth of the human gingival fibroblasts, compared to the control. Thus, the conclusion is reached that EPBPA oligomers have potential application in formulating dental composites as direct esthetic restorative materials with improved properties.