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61 6. Read and translate the following word-combinations: A visible structure, a visible part of the tooth, a visible rod, a visible surface, is covered by cementum, to cover the roots, to cover the cavity, the outer covering of the crown, a hard surface, a hard substance, a hard part, sensitive to cold, sensitive to antibiotics, to undergo some changes, to un‑ dergo repair, called enamel prisms, to cause tooth decay, at a right angle, to cause injury of a tooth, soft tissue, soft palate, blood vessels, apical foramen, pulp chamber, the inner layer, a thin layer, the outer layer, unlike other body tissues, the junction of crown and root, a bundle of vessels, a bundle of fb‑ ers, the process of growth, the process of repair, alveolar process. Reading 1 7. Read and translate the text. Structure of the Teeth. Supporting Structures Dentistry or stomatology is the science which deals with human teeth, gums, and dental arches, mucous, fbrous and periodontal membranes of the oral cavity. But still the central «fgure» of dentistry is a tooth. Each tooth has a crown, a neck and a root (or roots). The crown is the part visible in the mouth and the root is the part hid‑ den inside the jaw. The junction of crown and root is called the neck and the end of the root is called the apex. Every tooth is composed of enamel, dentine, cementum and pulp. Enamel. This is the outer covering of the crown and is the hardest sub‑ stance in the body. It is insensitive to pain. Unlike most other body tissues it cannot undergo repair; thus any damage caused by decay or injury is perma‑ nent. The microscope shows that it consists of long solid rods, called enamel prisms, cemented together by the interprismatic substance. The prisms run roughly at right angles to the surface. Cementum. This is the outer covering of the root and is similar in struc‑ ture to bone. Cementum meets enamel at the neck of the tooth. Dentine. This occupies the interior of the crown and root, and is very sensitive to pain. Dentine from elephants’ tusks is commonly known as  ivo- ry but is exactly the same dentine as that found in human teeth. Pulp. Unlike enamel, dentine and cementum, the pulp is purely soft tis‑ sue. It contains blood vessels and nerves, and occupies the centre of the dentine. Vessels and nerves of the pulp enter the root apex through the api- cal foramen and pass up the root canal  into the crown, where the space