Assessment of Dipotassium Oxalate Mouthrinse for Relief of Dentinal Hypersensitivity

Objectives: To evaluate the efficacy of a dipotassium oxalate mouthrinse (“experimental”) in reducing/controlling dentinal hypersensitivity compared to a placebo mouthrinse (“placebo”) in a multi-center, double-blind, parallel-group, randomized and controlled four-week clinical study.
Methods: At least two teeth, no more than two per quadrant, with scores at Screening and Baseline of Cold Air Stimulus (CAS) Visual Analog Scale (VAS) scores 40 – 80, tactile (Yeaple probe) sensitivity 10 –30 grams and tactile VAS score of 40 – 80, were needed for enrollment. After screening, subjects entered two-week, pre-study period using provided dentifrice and toothbrush. At baseline, eligible subjects were randomized into two twice-daily treatment groups – brushing, rinsing with water, then rinsing with 10 mL of either experimental or placebo for 60 seconds. Evaluations included above scoring and Global Subjective VAS. Primary efficacy variable was success (yes/no) for subject based on mean CAS VAS score >30% lower than subject mean baseline CAS VAS score at Week 4.
Results: 375 subjects were enrolled (186 placebo; 189 experimental); 361 completed. Primary endpoint: experimental had statistically significantly higher success rate compared to placebo (69.3% vs. 44.6%; p < 0.001); success rate difference between treatments was 24.7%, exceeding 20% needed to conclude superiority. There were no serious adverse events during the study. AEs in this study were considered to be within normal expectations for participation in a mouth rinse study.
Conclusions: Clinical superiority of experimental treatment over placebo treatment for both primary and four key secondary efficacy endpoints was jointly demonstrated at an overall, family-wise error rate at 5%. This study demonstrated that experimental dipotassium oxalate mouthrinse, when used twice daily as adjunct to tooth brushing provided a clinically meaningful benefit in reducing and controlling dentinal hypersensitivity compared to placebo. No safety issues were identified in this study.
ClinicalTrials.gov identifier: NCT02113579.