The study of a commercial dental resin by H-1 stray-field magnetic resonance imaging

A dentine/enamel resin containing methacrylate monomers, included in a new generation adhesive system, was used to evaluate the potentialities of rece nt nuclear magnetic resonance imaging (MRI) techniques to obtain spatially- resolved information on photo-polymerization reaction and subsequent polyme rization shrinkage. H-1 stray-field (STRAFI)-MRI one-dimensional images (ID profiles) of visible-light cured resins were obtained in the presence of o xygen from the atmosphere, and the variation of magnetization with irradiat ion time was recorded for each resin slice. The polymerization shrinkage wa s obtained from 1D profiles. The spatial distribution of the unreacted meth yl methacrylate groups was obtained from 3D STRAFI experiments. In particul ar, the thickness of the surface remaining unpolymerised was measured. (C) 2001 Elsevier Science Ltd. All rights reserved.