Dentine hypersensitivity--a review. Clinical and in vitro evaluation of treatment agents.

A large number of compounds have been employed in the management of dentine hypersensitivity. The symptomatic nature of the condition and its variability poses many problems to any evaluation of effect. Several semi-quantitative methods of response have been used; however, at this time it is uncertain what advantages they hold over the patients' subjective assessment of improvement. A review of the clinical studies reveals that a positive result for every agent tested to date may be found. Nevertheless considerable placebo responses have been obtained and equivocal results are occasionally reported. The fluorides and metal salts, particularly of strontium, have been most studied when used either in solution or delivered in toothpaste formulations. For these compounds the literature contains considerable information concerning the reaction with dental hard tissues which can be extrapolated into hypotheses for the modes of action in relieving dentine hypersensitivity. Moreover, some in vitro studies provide useful information concerning the effects of certain compounds on dentine, and are consistent with the clinical data. Unfortunately, contradictory findings and anomalies between clinical and in vitro effects still prevent the development of a sound clinical basis for the treatment of the condition. Moreover, there is a need to recognise those factors which predispose to dentine exposure, if the prevention of the occurrence or re-occurrence of hypersensitivity is to be achieved.