Nature-Inspired Nacre-Like Composites Combining Human Tooth-Matching Elasticity and Hardness with Exceptional Damage Tolerance.

Abstract

Making replacements for the human body similar to natural tissue offers significant advantages but remains a key challenge. This is pertinent for synthetic dental materials, which rarely reproduce the actual properties of human teeth and generally demonstrate relatively poor damage tolerance. Here new bioinspired ceramic-polymer composites with nacre-mimetic lamellar and brick-and-mortar architectures are reported, which resemble, respectively, human dentin and enamel in hardness, stiffness, and strength and exhibit exceptional fracture toughness. These composites are additionally distinguished by outstanding machinability, energy-dissipating capability under cyclic loading, and diminished abrasion to antagonist teeth. The underlying design principles and toughening mechanisms of these materials are elucidated in terms of their distinct architectures. It is demonstrated that these composites are promising candidates for dental applications, such as new-generation tooth replacements. Finally, it is believed that this notion of bioinspired design of new materials with unprecedented biologically comparable properties can be extended to a wide range of material systems for improved mechanical performance.