Spatial summation of pre-pain and pain in human teeth

Pain. 1985 Jan;21(1):1-16. doi: 10.1016/0304-3959(85)90071-5.


The purpose of this work was to investigate the relation between the sensations of pain and 'pre-pain' evoked by stimulation of teeth in human subjects. Electrical pulses of progressively increasing amplitude, generated by a computer-controlled stimulator, were applied to 1 or 2 teeth, and the subjects responded by indicating the nature of the resulting sensation. Pre-pain and pain could be readily and rapidly distinguished by all 11 subjects (response latency about 0.4 sec). Both sensations had stable thresholds with relatively small variance (S.D. 10-15% of threshold value) for a given subject. Subjects characterized the stimuli as indifferent or unpleasant, localized, and brief. By using special stimulation strategies (termed 'optimal trajectories') for exciting 2 teeth simultaneously, spatial summation for pre-pain was demonstrated in most subjects and for pain in almost all subjects. Spatial summation of pre-pain resulted in pain rather than in more intense pre-pain. These results are consistent with both the dual modality (separate afferent fibers for pre-pain and pain) and the single modality hypotheses (single type of afferent fibers) of tooth pulp sensibility, but favor single modality innervation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Afferent Pathways
  • Autonomic Fibers, Preganglionic / physiology
  • Electric Stimulation
  • Female
  • Humans
  • Male
  • Nerve Fibers / physiology
  • Pain / physiopathology*
  • Sensation
  • Sensory Thresholds
  • Tooth / innervation
  • Tooth / physiology*