No abstract

Our experience suggests that the management of MSI should be more aggressive when the above risk factors are present, in order to avoid life-threatening complications. In addition, considering the poor medical conditions in the rural areas of West China, standard dental care and services should be provided in the future to replace self-medication.

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 we report on new bioinspired ceramic-polymer composites with nacre-mimetic lamellar and brick-and-mortar architectures 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. We demonstrate that these composites are promising candidates for dental applications, such as new-generation tooth replacements. Finally, we believe 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.

Biological material systems have evolved unique combinations of mechanical properties to fulfill their specific function through a series of ingenious designs. Seeking lessons from Nature by replicating the underlying principles of such biological materials offers new promise for creating unique combinations of properties in man-made systems. One case in point is Nature's means of attack and defense. During the long-term evolutionary "arms race," naturally evolved weapons have achieved exceptional mechanical efficiency with a synergy of effective offense and persistence-two characteristics that often tend to be mutually exclusive in many synthetic systems-which may present a notable source of new materials science knowledge and inspiration. This review categorizes Nature's weapons into ten distinct groups, and discusses the unique structural and mechanical designs of each group by taking representative systems as examples. The approach described is to extract the common principles underlying such designs that could be translated into man-made materials. Further, recent advances in replicating the design principles of natural weapons at differing lengthscales in artificial materials, devices and tools to tackle practical problems are revisited, and the challenges associated with biological and bioinspired materials research in terms of both processing and properties are discussed.