Enamel-inspired materials for tooth restorations
TOOTH ENAMEL, serving as barrier against chewing wear, is the hardest, stiffest and most mineralized tissue of the human body. It is remarkably resilient and damage-resistant to cumulative deformation over extended lifetime, protecting the enclosed dentin and pulp. Synthetic dental materials however rarely match the performance of natural teeth. Irrespective of being metal, ceramic or polymer based, they generally have performance TRADE-OFFs between stiffness, toughness and translucency. Bioinspired materials, mimicking the specific hierarchical structures of natural materials, have shown to be promising solutions, but the potential of tooth enamel has to date been overlooked with little or no attempt to mimic its multiple energydissipating and crack-shielding mechanisms. Therefore, we will use ADDITIVE MANUFACTURING, more specifically direct-ink-writing (DIW), to make dental ceramics (zirconia, alumina) and resin-based composites that mimic the functional gradients and textured structures of tooth enamel. Zirconia with varied yttria contents, forming a tough core and translucent surface will be printed. Reinforcing flakes and fibers will be aligned in alumina and resinbased composites, respectively, and printed, prompting crack-arrest mechanisms. The targeted materials are expected to overcome or at least minimize the performance trade-offs and obtain unprecedented damage-tolerance and durability combined with high strength, stiffness, toughness and aesthetic appearance.