Efficacy of an experimental 3% potassium nitrate mouthwash in providing long-term relief from dentin hypersensitivity:An 8-week randomized controlled study (Study 1).

PURPOSE

To evaluate the efficacy of an experimental mouthwash containing 3% potassium nitrate (KNO3) in relieving dentin hypersensitivity when used as an adjunct to brushing with fluoride toothpaste compared with use of the same toothpaste alone.

METHODS

This was one of three randomized, two-treatment, examiner-blind, parallel-design, single-site, 8-week studies in healthy subjects with self-reported and clinically diagnosed dentin hypersensitivity. Subjects were randomized to receive either fluoride toothpaste plus 3% KNO3 mouthwash or the same fluoride toothpaste alone, and instructed to use their allocated treatment twice daily for the next 8 weeks. Dentin hypersensitivity was evaluated at baseline and following 4 and 8 weeks of treatment through assessment of responses to evaporative (air) and tactile stimuli [measured by the Schiff Sensitivity Scale, a visual rating scale (VRS), and tactile threshold, respectively], and using the Dentin Hypersensitivity Experience Questionnaire (DHEQ; a validated quality-of-life instrument for dentin hypersensitivity).

RESULTS

A total of 216 subjects were randomized and 214 completed the study. Both treatment groups demonstrated statistically significant reductions from baseline for each clinical measure of sensitivity (P≤ 0.01) at Weeks 4 and 8. Use of the 3% KNO3 mouthwash after brushing with fluoride toothpaste resulted in statistically significantly greater reductions in sensitivity to an evaporative (air) stimulus (mean Schiff score and mean VRS, P< 0.001; primary objective mean Schiff score at Week 8, P< 0.0001) and statistically significantly higher tactile threshold (P< 0.001) at Weeks 4 and 8 compared with toothpaste alone. The DHEQ responses reflected the clinical outcomes for several parameters, indicating a significant improvement in oral health-related quality of life after 8 weeks' use of the 3% KNO3 mouthwash.

CLINICAL SIGNIFICANCE

The results of this study suggest that daily use of a 3% KNO3 mouthwash as an adjunct to brushing with fluoride toothpaste provides clinically relevant improvements in dentin hypersensitivity after 8 weeks' twice-daily use.