Characterization of composite resins by NMR and TEM

This investigation demonstrated that the monomer composition of the investigated restorative resins varied from brand to brand. The NMR analysis showed that most filling materials contained the bis-GMA, iso-bis-GMA, and TEDMA monomers in varying concentrations. The high TEDMA monomer concentration in the smooth-surface composites and, in one case (Isopast and Isocap), the total absence of the bis-GMA system are clearly evident. We can, therefore, expect that the clinical properties of the microfilled, smooth-surface materials cannot be generalized inside the group, and that they will differ from those of the conventional composites. The use of submicron filling particles in the matrix phase is also present in some conventional materials.