Carried out at the Faculty of Medicine of Marseilles, this placebo controlled study was designed to determine the effectiveness of Arnica 7C and Hypericum 15C for people suffering from dental neuralgia. 60 people received either 4 pilules of Arnica alternated with 4 pilules of Hypericum every 4 hours or placebo administered in the same way. Pain levels were assessed over 3 days from the beginning of the trial. From this assessment it was found that 12 of the 30 people who received the placebo had a positive response to this intervention, and 23 of the 30 people given the homeopathic medicines responded positively to these.
Albertini H, Goldberg W, Sanguy B, Toulza CL. Homeopathic treatment of dental neuralgia by Arnica and Hypericum. Journal of the American Institute of Homeopathy, 1985, 3, 126-129.