Dentine. Coloured scanning electron micrograph of dentine - the dense, calcified material that forms most of the body of a tooth under the enamel crown. Dentine is similar to bone in composition but is more highly mineralised and consequently much harder. It is riddled with microscopic pores called dentinal tubules (dark spaces). These run from the tooth's inner pulp cavity to the dentine- enamel border and contain cytoplasmic processes of dentine-forming odontoblast cells. Some of the tubules also contain nerve fibres. Dentine is highly sensitive to touch and extremes of temperature, both of which are perceived as pain. Magnification x1050 at 7x5cm size. x1400 at 4x5 inch size.