Fatigue Characterization of In-Situ Self-Healing Dental Composites

Abstract

The short-term failures of dental composites are a common limitation of these materials. Oral conditions apply fatigue load cycles in the form of chewing and thermal loads, and the damage due to fatigue loads plays a major role in restorative failures in the form of cracks. A lab-based fatigue test is a suitable technique to characterize the crack propagation in dental composites. In this paper, we investigate the ability of a self-healing material to repair or arrest propagating fatigue cracks. In-situ self-healing resin composites were prepared using 15 wt% of activator resin microcapsules and 5 wt% of initiator microcapsules, and equal amounts of 40 wt% each of dental filler and dental resin. Compact Tapered Double Cantilever Beam (cTDCB) specimens of self-healing dental resin composites were prepared by integrating two sets of microcapsules of diameter 45 ± 10 μm containing an acrylate monomer and a polymerization initiator (BPO). Samples were tested in a servo-hydraulic load frame in air at room temperature. Three specimen types are investigated, dental composite without microcapsules, dental composite with non-healing microcapsules, and dental composite with in-situ self-healing microcapsules. The results show that the in-situ self-healing dental composite successfully extended the life of the composite compared to the control samples.