An exploratory clinical trial to evaluate the efficacy of an experimental dentifrice formulation in the relief of dentine hypersensitivity

Abstract Objectives This study aimed to investigate whether addition of an octadecene/maleic anhydride copolymer (O/MA) to a potassium nitrate (KNO 3 ) dentifrice could facilitate delivery of potassium to dentine and enhance its efficacy in dentine hypersensitivity relief. Methods This was a randomised, examiner-blind, controlled, parallel group study in 139 healthy subjects with at ≥2 sensitive teeth. Assessment of dentine hypersensitivity to tactile (Yeaple probe) and evaporative (air) stimuli (Schiff Sensitivity Scale, visual analogue scale [VAS]) was carried out at baseline and after 1, 2, 4 and 8 weeks twice daily treatment with an experimental 5% KNO 3 /3% O/MA dentifrice, a comparator 5% KNO 3 dentifrice (active comparator), a 0% KNO 3 /3% O/MA dentifrice (placebo) and a regular fluoride dentifrice (negative control). This study was not powered to detect statistically significant differences between treatments. Results Across the treatment period an improvement in sensitivity to evaporative air stimulus was observed for all products and to a tactile stimulus for the potassium-containing treatments, with the greatest reductions for the experimental dentifrice (5% KNO 3 /3% O/MA). Reductions in sensitivity observed for the potassium-containing dentifrices compared to the placebo and negative control dentifrices were statistically significantly for Schiff sensitivity score and tactile threshold at all time-points and for VAS at Weeks 4 and 8. Trends in the study data also favoured the experimental dentifrice, compared to the active comparator dentifrice, for all clinical measures. Study treatments were generally well tolerated. Conclusion This study provides initial clinical evidence to suggest that addition of a polymer excipient may enhance the anti-sensitivity efficacy of potassium-containing dentifrices. Clinical significance Daily use potassium-containing dentifrices are established as efficacious for the relief of dentine hypersensitivity. Inclusion of a polymer excipient in such formulations may facilitate delivery of potassium to the dentine surface and so enhance clinical efficacy. Further clinical studies are required to confirm this hypothesis.