Instrument for measuring perimeter of tooth - has fine wire fixed to stud on rigid shaft passing round tooth to spool mounted in sleeve

摘要

The densimeter measures the perimeter of a tooth for fitting an artificial crown. The instrument has a main shaft with a length of fine wire passing alone one side. The wire is fixed at one end to a stud (3) and passes over a pair of aperture shoulders (5, 6) along the shaft to a spool of wire wound on a bobbin. The bobbin is seated in a rigid sleeve at one end of the shaft. The tooth is measured by forming a tight loop of wire round the perimeter then measuring the length of wire used.