Effect of monomer type on the C C degree of conversion, water sorption and solubility, and color stability of model dental composites

Autor: Luis Felipe Jochims Schneider, Carmem S. Pfeifer, Pedro Paulo A.C. Albuquerque, Allana Dutra Labruna Moreira, Lívia Rodrigues de Menezes, Andrea Soares Quirino da Silva Fonseca
Rok vydání: 2017
Předmět:
Zdroj: Dental Materials. 33:394-401
ISSN: 0109-5641
Popis: Objective This study has investigated the influence of BisGMA, BisEMA, BisEMA 30, and two UDMA-based monomers (UDMA and Fit 852), with TEGDMA as co-monomer, on the degree of conversion, water sorption, water solubility, and optical properties of experimental dental composites. Methods Materials were formulated at 70/30 molar rations using BisGMA, BisEMA, BisEMA 30, UDMA or FIT 852, as base monomers, combined with TEGDMA. 60 wt% of silanated-glass particles was added. Degree of conversion (DC) and polymerization kinetics were monitored using Fourier-transformed infrared spectroscopy in the near-IR range. Water sorption (Wsp) and solubility (Wsl) were assessed using mass variation after 60 days water storage. Color was evaluated using a digital spectrophotometer, applying the CIELab parameters 24 h after dry storage and 60 days after water immersion to calculate ΔE values. All data were analyzed using ANOVA and Tukey’s test (pre-set alpha = 0.05). Results The BisGMA-based co-monomer mixture presented the lowest DC (62 ± 1%), whereas BisEMA 30 had the highest DC value (95 ± 2%). The highest Wsp was observed for BisEMA 30 (12.2 ± 0.8%), and the lowest for BisEMA (0.4 ± 0.1%). BisEMA has shown the lowest Wsl (0.03 ± 0.01%) and BisEMA 30 the highest one (0.97 ± 0.1%). The ΔE values showed that BisEMA 30 (7.3 color units) and Fit 852 (3.8 color units) altered the color stability providing ΔE > 3.3, which is considered clinically unacceptable. Conclusions The chemical composition and structure of the base monomer influenced the degree of conversion, water sorption, water solubility, and color stability. Considering the overall results, it is possible to state that the base monomer BisEMA mixed with the co-monomer TEGDMA presented the best performance in terms of all the parameters tested. Significance The resin matrix composition might influence physical property degradation processes and color stability of dental resin composites. Formulations based on BisEMA seem most promising for materials’ development.
Databáze: OpenAIRE