IN-SITU OBSERVATION OF FRACTAL STRUCTURES AND ELECTRICAL-CONDUCTIVITYIN HUMAN TOOTH ENAMEL

In this paper we present two phenomena observed in situ when human too th enamel is heated in the transmission electron microscope. One is th e deposition of hydrocarbon molecules on the enamel surface, forming f ractal structures ('bushes'), and the other is the dielectric-to-condu ctive transition that this material presents. The explanation of the f ractal phenomenon is the reaching of an umbral energy after which an e lectrical field appears, producing these structures, whereas the condu ctivity phenomenon is a behaviour which enamel presents with increasin g temperature. It seems that for the fractal phenomenon the electron b eam and a high temperature are necessary elements for its appearance: for the electrical conductivity, a high temperature is the only requir ement. All this opens some potential technological applications for hy droxyapatite, the principal component of tooth enamel.