Caption

Enamel. Coloured Scanning Electron Micrograph (SEM) of human tooth enamel. Enamel is the hard- est, most durable substance in the human body. It consists of parallel rods of translucent calcified material (mostly calcium phosphate and calcium carbonate) that cover the crown of the tooth. Enamel can deteriorate over a period of time if bacteria are allowed to build up on teeth in plaque. These decay-causing bacteria ferment the remains of food left on the teeth, producing acids that dissolve the minerals in enamel. Magnification unknown.