Novel experimental methods to investigate the effects of plant phytoliths on tooth enamel wear.

Dental enamel is one of the strongest biomaterials found in nature, making its mechanical failure of significant interest to the biomaterials and dental communities. Recent studies on the mechanisms of enamel wear have yielded conflicting results, highlighting the need for more realistic experimental approaches. Here, we introduce a novel experimental methodology based on nanotechnology techniques and micromechanical/materials testing to simulate and characterize, for the first time, in vitro microwear caused by the sliding of artificial models of soft leaves containing phytolith particles against human dental enamel. While embedded phytoliths undergo mechanical degradation upon cyclic contacts, they increase the extent of pre-existing wear in enamel and decrease its mineral content. Surprisingly, the primary wear mechanism of enamel is 'quasi-plastic' (i.e. permanent) deformation enabled by failure of weak interphases, dominated at the microstructural scale. Mechanisms responsible for material removal in enamel at different length scales are identified and discussed. This research offers new insights into enamel failure that can further reveal information about an animal's biology, behaviour, biomechanics and ecology, offering an interdisciplinary approach to the interface between the physical and life sciences.