Enamel: From brittle to ductile like tribological response

The wear behaviour of enamel at the nano-level resembles that obtained with glass at low loads (50 μN) and that obtained with metal mono-crystals at high load (100 μN). The role of the microstructural heterogeneity in the wear behaviour of enamel is considered in the discussion. The relevance to clinical wear of enamel is also considered.