Comparison of surface layer properties of composite resins by ESCA, SEM and X-ray diffractometry

Hyperfine surface layer properties of three types of dental composite resins, highly-filled, conventional, and micro-filled resins, were studied using X-ray photoelectron spectroscopy (ESCA) by a combination of X-ray diffractometry and scanning electron microscopy (SEM). X-ray diffraction and SEM analysis showed clearly that each resin has different characteristics of SiO2 particle size and distribution. ESCA depth resolution with argon ion etching indicated that, in contrast to conventional and microfilled resins, carbon due to polymers of highly-filled resin decreases dramatically with increasing depth in the nanometer range of the resin-rich surface layer.