The effect of adding a new monomer 'Phene' on the polymerization shrinkage reduction of a dental resin composite

摘要

Objective. A new photocurable monomer, "Phene" (N-methyl-bis(ethyl-carbamate-isoproply-alpha-methylstyryl)amine) was synthesized and incorporated into Bis-GMA/TEGDMA with the aim of reducing polymerization shrinkage swithout detriment to the physical properties and wearing of the resin composites.Methods. Phene was synthesized through a 2-step reaction route, and its structure was confirmed by FT-IR and H-1-NMR spectra. Phene was incorporated into Bis-GMA/TEGDMA (50/50, wt/wt) with a series of mass fraction (from 0 wt% to 40 wt%). Experimental resin composites were prepared by mixing 29 wt% of resin matrix to 71 wt% of particulate-fillers. Degree of conversion (DC) was determined by FT-IR analysis. The volumetric shrinkage (VS) was calculated as a buoyancy change in distilled water by means of the Archimedes principle. Polymerization shrinkage-stress (SS) was measured using the tensilometer technique. The flexural strength (FS), modulus (FM), and fracture toughness (FT) were measured using a three-point bending setup. A wear test was conducted with 15000 cycles using a dual-axis chewing simulator. Wear depth was measured by a three-dimensional (3D) non-contact optical-profilometer.Results. ANOVA analysis showed that when mass fraction of Phene in resin matrix was more than 10 wt%, the obtained resin composite formulation had lower DC, VS and SS than control resin composite (p 0.05). In general, the experimental resin composites had comparable FS and FM (p 0.05) when the mass fraction of Phene in resin matrix was not more than 20 wt %. Resin composite with 20 wt% Phene had the lowest wear depth and fracture toughness values.Significance. The overall tested properties prove that including Phene up to 20 wt% into Bis-GMA/TEGDMA resin could be potentially useful in the formulation of low-shrinkage resin composites. (C) 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.