The measurement of degree of conversion for BIS-GMA/silica composites by FT-IR spectroscopy

2'-bis[4-(methacryloxy-2-hydroxy-propoxyl-phenyl]-propane (BIS-GMA)/silica com- posites were fabricated by visible light cure. The degree of conversion IDC) of the dental composites were measured by Fourier transform infrared (FT-IR) spectroscopy. The effects of several factors on DC were examined. The chosen factors were filler content, diluent concentration, radiation time, posture effect, cure mode, initiator concentration, and inhibitor concentration. DC increased with increasing silica content, diluent concentration, and initiator concentration. Cure time, postcure and cure mode respectively caused significant DC increases. The DC of the same visible light cure mode was in proportion to dimetral tensile strength (DTS). Copyright (C) 1996 Elsevier Science Ltd