• Martin, Richard A.
• Nicolae, Laura C.
• Shelton, Richard M.
• Cooper, Paul R.
• Palin, William M.

Abstract

<p>Light curable dimethacrylate resin composites undergo free radical photopolymerisation in response to blue light (wavelength 450-500 nm) and may offer superior handling and setting characteristics for novel hard tissue repair materials. The current investigation aims to determine the optimum formulation of bisphenol-A glycidyl methacrylate and triethyleneglycoldimethacrylate (bisGMA/TEGDMA) or urethane dimethacrylate (UDMA)/TEGDMA resin mixtures and the effect of Bioglass incorporation on the rate of polymerisation (RP), degree of conversion (DC) and flexural strength (FS) of light-curable filled resin composites (FRCs). Experimental photoactive resins containing a range of bisGMA, UDMA and TEGDMA ratios and/or filled with non-silanised irregular or spherical 45S5-Bioglass (50 μm; 5-40 wt%) and/or silanised silicate glass filler particulates (0.7 μm; 50-70 wt%) were tested. RP and DC were analysed in real-time using nearinfrared spectroscopy. FS of resins and FRCs were determined using three-point flexural strength tests. UDMA/TEGDMA resins exhibited increased DC compared with bisGMA/TEGDMA resins (p&lt;0.05). The addition of spherical particles of Bioglass had a detrimental effect on the FS (p&gt;0.05), whereas they increased DC of UDMA/TEGDMA resins (p&lt;0.05). Addition of irregular shaped Bioglass particles increased the FS of UDMA/TEGDMA resins up to 20 wt% Bioglass (p&lt;0.05). The flexibility and strength conferred by the urethane group in UDMA may result in enhanced physical and mechanical properties compared with conventional resins containing bulky (bisGMA) molecules. Addition of 45S5-Bioglass with specific filler content, size and morphology resulted in enhanced mechanical and physical properties of UDMA/TEGDMA composites.</p>

Topics

• glass
• glass
• strength
• composite
• flexural strength
• resin
• spectroscopy