The relationship between the surface area of the enamel crowns of human teeth and that of the dentine-enamel junction

Abstract The surface area of the enamel and that of the dentine-enamel junction and the volume of enamel were calculated using a computer-based three-dimensional reconstruction technique. The surface area of the dentine-enamel junction was compensated for its pitted nature. Different individual teeth had wide variation in surface areas but, for the same kind of tooth the ratio between the surface area of the enamel and that of the dentine-enamel junction was very similar. Only a small amount (8–17 per cent) need be added to the thickness of crystals emerging normal to the enamel surface to account for the difference in surface areas. If it is assumed that crystals have uniform width and thickness, the angle of emergence of the crystals observed is sufficient to provide the required increase in the enamel surface area.