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 mu 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 (KO 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 degrees C at 2 degrees /min and 1 Hz. Storage and loss modulus, T-g and tan delta, 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. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 428-434, 2010