Aspects of FUDMA as a matrix resin for dental resin composite

Abstract

For years, bis-phenol A glycidyl methacrylate (bis-GMA) has been extensively used as the resin matrix in dental restorative resin composites. However, it is believed the presence of bis-phenol A (BPA) may be leached from bis-GMA containing materials and possibly act as an oestrogen-like agent that may have potential health risks. As such, it is necessary to develop BPA-free monomers to replace bis-GMA in dental composites. Recently, a novel fluorinated urethane dimethacrylate (FUDMA) monomer was synthesised which has shown comparable physicochemical properties with bis-GMA-based resins. However, information on the performance and potential use of this FUDMA resin remains limited and requires further evaluation. The aim of this project was to evaluate the mechanical properties as well as cytotoxicity of FUDMA-based resin matrix polymer compared with bis-GMA resins. In addition, glass fibres were incorporated into the FUDMA resin to evaluate its potential as a fibre-reinforced composite material for clinical application. A systematic review was conducted to garner information on the biological properties of fibre-reinforced composites (FRCs) by assessing the existing literature. A systematic search of four databases (PubMed/MEDLINE, Scopus, Web of Science and Cochrane library) was performed from which a total 10 papers were included. The findings of the review concluded that FRCs are biocompatible materials, but there is the need for more information to better understand biological and clinical application. The second part of this project investigated the photopolymeization, nanoindentation elastic modulus, water sorption and ageing effects on the Vickers hardness of the FUDMA-based resin in comparison with bis-GMA resin-based matrix. The FUDMA resin demonstrated a higher degree of conversion, greater hardness and lower elastic modulus. However, it absorbed more water than the bis-GMA resin. Accordingly, the FUDMA resin showed good potential as a replacement of bis-GMA. The third part examined the cytotoxicity and antibacterial properties of the FUDMA resin and bis-GMA resin. The FUDMA resin system possessed superior cytocompatibility properties when tested with the MC3T3-E1 cell line. However, the results were comparable between the two resin when S. mutans bacterial adherence and viability was examined. In fourth study, the mechanical properties of fibre-reinforced different combinations of FUDMA/TEGDMA (30/70wt%, 50/50wt%, 70/30wt%) were investigated. Compared with fibre-reinforced bis-GMA composites, the 70wt% FUDMA-FRC demonstrated the greatest surface hardness among all groups, and possessed a comparable flexural strength, water sorption and solubility to the 70wt% bis-GMA-based FRC. The last part of this research project investigated the biocompatibility of different ratios of FUDMA/TEGDMA (30/70wt%, 50/50wt%, 70/30wt%) based FRCs. The viability of MC3TC-E1 cells in all FUDMA-FRC groups was better than those for the bis-GMA groups. The groups containing a higher concentration of FUDMA showed a positive effect on cell proliferation. FUDMA-based FRCs possess a superior cytocompatibility compared with the bis-GMA-FRCs. In conclusion, the FUDMA resin was demonstrated to show a good capability of being a suitable alternative resin matrix monomer for the replacement of bis-GMA. When combined with glass fibres, again the FUDMA resin was observed to create a suitable FRC, displaying comparable mechanical properties and cytocompatibility findings to the bis-GMA-based FRC.