Residual monomer content and its release into water from the denture base nanocomposite using organic montmorillonite as reinforcement

Abstract

A novel kind of denture base nanocomposite was prepared by polymethyl methyacrylate(PMMA) and cethyltrimethylammonium bromide modified organic montmorillonite (OMMT). The dispersion of montmorillonite in the polymer matrix was characterized by x-ray diffraction (XRD) and transimission electron microscope (TEM).The content of residual MMA in nanocomposites and the amount of MMA released to water from nanocomposites were determined by gas chromatography (GC). The analysis of TEM and XRD showed that exfoliated-intercalated and intercalated nanocomposites were formed when the content of OMMT was 3% and 5% in the PMMA powder respectively. The results of GC showed that the residual MMA increased with the increase of OMMT content in the polymer matrix. After 7 days in water, the amount of MMA released into water from the nanocomposites tended to be stable. The results of one-way ANOVA and t-test showed that OMMT gave a significant increase of residual MMA concentration (p<0.05) in nanocomposites.