THE USE OF TOPICAL GUANETHIDINE IN THE RELIEF OF DENTIN HYPERSENSITIVITY - A CONTROLLED-STUDY

After a pilot study had indicated that the topical application of guanethidine might be of value in the treatment of tooth dentine hypersensitivity, a double-blind study was undertaken to investigate whether guanethidine was more effective than a distilled water control in alleviating dentinal pain. In 39 adult subjects, who had complained of dentine hypersensitivity, a 1 sec blast of air from a dental 3-in-1 syringe was directed onto sensitive root dentine at an angle of 90-degrees from a distance of 1 cm. The severity of the resulting pain was indicated by the subject on a 10 cm visual analogue scale (VAS). One droplet of either 1% guanethidine monosulphate (Ismelin, Ciba-Geigy) or distilled water, allocated at random, was applied to the dentine for 1 min. The tooth was re-tested with the standardised air blast and a second VAS was marked by the subject. In total, 19 patients received guanethidine and 20 received water. VAS scores before treatment in the 2 groups treated with either guanethidine or water (means: 6.5 +/- 2.2 and 6.0 +/- 2.5, respectively) were not significantly different (Mann-Whitney, P = 0.48) whereas the VAS scores in the 2 groups after treatment with guanethidine or water (means: 2.7 +/- 2.4 and 4.8 +/- 2.9, respectively) were significantly different (Mann-Whitney, P < 0.02). It was concluded that guanethidine reduced dentinal hypersensitivity more effectively than distilled water. Within-group comparison of the pre- and post-treatment VAS scores, using the Wilcoxon matched-pairs test, showed that distilled water had also produced a significant improvement (P < 0.01), probably attesting the operation of a placebo effect; the improvement produced by guanethidine reached a greater level of significance (P < 0.001). This beneficial analgesic action of guanethidine may offer a novel, simple method of relieving the discomforts of dental conservation and restoration and lead to a better understanding of the hitherto obscure aetiology of dentinal pain.