Time-resolved study of the photo-curing process of dental resins with the NMR-MOUSE

Abstract

The photo-curing reaction of dental resins has been examined with unilateral nuclear magnetic resonance (NMR-MOUSE) allowing nondestructive high-resolution measurement of depth profiles as a function of time and space. The NMR signal is sensitive to both the monomer concentration and changes in molecular mobility. Upon irradiation with blue light, it first increases due to molecular mobility enhanced by the reaction heat and then decreases exponentially with the monomer concentration as the polymer signal is lost in the dead time of the instrument upon curing. The space and time dependence of the NMR signal can be described by the photo-polymerization reaction kinetics together with a heuristic approximation of the temperature dependence. © 2013 Springer-Verlag Wien.