Remote measurement of in-vivo toothbrushing forces as a clinical tool for dental hygiene purposes

The design of an electric pressure-sensitive toothbrush, capable of measuring the forces applied to the head of the brush, through the bristle axis, during toothbrushing is described. Brushing forces are measured by a differential strain gauge cantilever bridge. Acquired data are processed through a programmable microcontroller for relay by a miniature UHF radio transmitter to a remote personal computer for graphical display. Modern microelectronic manufacturing allows the force-measuring apparatus, radio transmitter and power source to be fitted within the casing of a commercially-available electric toothbrush. The graphical display is a plot of absolute force (g) with time over a 2 min brushing period. The instrument was conceived to aid dental care personnel in patient education and instruction in oral hygiene, with the particular aim of preventing tissue damage from excessive brushing pressures.