Tooth—A natural biocomposite

Abstract

The inorganic content of human tooth is predominantly hydroxyapatite. The content varies in enamel and dentin. A reversible thermal transformation at 157 C is observed and has correspondence in the dielectric measurements. The dental decay is related to the piezoelectric property of tooth, which is similar to a polar glassceramic. The toughness of tooth is higher than hotpressed hydroxyapatite and owes it to the microstruct ure signifying the importance of a weak, pliable interface. The hardness is graded, higher for enamel in the crown and very much lower for dentin, to suit their function and environment. The relevance of biomimics in designing materials for advanced performance is discussed.