An exploratory randomised controlled clinical trial to evaluate the efficacy of an experimental toothpaste in the relief of dentine hypersensitivity

Objectives
Investigate efficacy of an experimental 3% polyvinyl methyl ether/maleic anhydride co-polymer (PVM/MA)+5% potassium nitrate (KNO3) toothpaste (Test), to reduce dentine hypersensitivity (DH), compared to toothpastes containing: 3% PVM/MA (Comparator-1) or 5% KNO₃ (Comparator-2) or fluoride (Negative control), following twice-daily use over 8 weeks.

Methods
A single-centre, 8-week, randomised, controlled, examiner-blind, parallel design, stratified study in healthy participants with >2 sensitive teeth. Evaporative air and Yeaple tactile stimuli were measured by Schiff sensitivity score and tactile force. Participants completed a DH experience questionnaire (DHEQ-15) and self-perceived pain numeric rating scale (NRS). Participants were stratified by maximum test teeth baseline Schiff score and randomised to one of four treatments. Mean change from baseline in test teeth for Schiff and tactile force, at 3 days and 2, 4 and 8 weeks, were analysed using analysis of covariance.

Results
118 participants completed the study. By week 2 the Test paste reduced DH significantly more from baseline compared to Comparator-1, -2 and Negative control for Schiff sensitivity (-0.3 p=0.009, -0.67 p<0.001; -1.44 p<0.001) and tactile force (8.97 p<0.001; 17.71 p<0.001; 32.81 p<0.001) respectively. DH continued to decrease for Test and Comparator-1 to week 8. Significant between group differences were not seen for NRS or DHEQ, baseline imbalances confounding analysis.

Conclusion
The Test toothpaste containing 3% PVM/MA + 5% KNO₃ was superior to the other 3 toothpaste treatments in reducing DH at all time points for both DH stimuli over an 8 week period apart from Comparator 1 at Day 3 for the evaporative stimulus.