Psychophysiological assessment of transcutaneous electric nerve stimulation (TENS) effects upon orofacial pain.

Fear of pain in dentistry may be one reason why preventive care is avoided by a number of individuals. Therefore, measures which reduce painful experiences may be beneficial for patients' attitudes towards medical interventions. Using conservative dental treatment as a model situation, we studied effects of transcutaneous electric nerve stimulation (TENS) upon acute orofacial pain in three experiments. In the first experiment, pain thresholds (electric tooth stimulation) were found to be increased under TENS. In the second experiment, electric brain potentials (ERP) were evoked by electric tooth stimulation. The ERP amplitude is intensity-dependent and revealed a marked decrease as a consequence of TENS. Finally, TENS was applied during real treatment, and subjective estimates confirm its beneficial effect upon pain and stress.