Degree of conversion of composites measured by DTA and FTIR

摘要

Objective. Differential thermal analysis (DTA) using a split fiber optic light source has been reported to be a convenient method of measuring the degree of conversion (DC) of light-activated composites. The purpose of this study was to compare the results by DTA and Fourier transformation infrared spectroscopy (FTIR), and evaluate the usefulness of the DTA method. Methods. Experimental 2,2-bis[4-3-methacryloyloxy-2-hydroxypropoxy]phyenyl]propane-based composites containing SiO_2 filler and Various amounts of triethyleneglycol dimethacrylate (TEGDMA) were prepared, and the DC of each composite was determned by DTA Or FTIR with 60 s irradiation. The DC of three proprietary composites containing hybrid filler or prepolymerized resin filler were also Measured by both methods with 20 or 60 s irradiation. The results were analyzed by ANOVA and Fisher's protected least significant Difference test.