Molar teeth. Polarised light micrograph (PLM) of a section through molar teeth. These teeth, at the sides of the mouth, are used for grinding up and chewing food. They are capped with enamel (orange/pink, across top), the hardest substance in the body, which limits mechanical wear. Each tooth is anchored in the gum by two roots (dark vertical strips). These run down from the pulp cavities (solid purple areas), which contain a pulp of nerves and blood vessels. The pulp is surrounded by dentine (many colours), which forms the bulk of each tooth. Dentine is similar to, but harder than, bone. Magnification: x1.7 at 35mm size.