Physical characterization of a self‐healing dental restorative material

The objectives of this study were to determine the efficacy of self‐healing a highly filled composite and to investigate the physical properties of a model dental compound formulated to autonomically heal cracks. A visible light cured model resin consisting of TEGMA : UDMA : BisGMA (1 : 1 : 1) at 45% w/w with silane 0.7 μ glass was formulated with a self‐healing system consisting of encapsulated dicyclopentadiene and Grubbs' catalyst. The base resin was also formulated and characterized with the microcapsules alone, Grubbs' catalyst alone, and no healing additives. Fracture toughness ( K Ic ) was assessed using single edge notch specimens in three‐point bend ( n = 12). Data was analyzed with ANOVA/Tukey's at p ≤ 0.05. DMA was performed from −140 to 250°C at 2°/min and 1 Hz. Storage and loss modulus, T g and tan δ, was recorded for each material. The self‐healing material was loaded to failure, was left to sit for 7 days and then loaded a second time to failure to determine healing in the material. These specimens had a K Ic = 0.69 ± 0.072 for a 57% average recovery rate of the original fracture toughness. The fracture toughness of the self‐healing material was statistically similar to the control. The modulus decreased in the composites with encapsulated dicyclopentadiene. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010