A Randomized Non-Inferiority Clinical Study to Evaluate the Efficacy of Two Dentifrices for Dentin Hypersensitivity

Calcium sodium phosphosilicate (CSPS) is a particulate bioactive material incorporated into oral healthcare products for the treatment of dentin hypersensitivity (DH). This study aimed to determine whether a dentifrice containing 5% CSPS and fluoride as sodium fluoride (NaF; "Test dentifrice") was non-inferior to a dentifrice containing 5% CSPS and fluoride as sodium monofluorophosphate (SMFP; "Comparator dentifrice") in reducing DH after eight weeks' twice-daily brushing.

This was a randomized, examiner-blind, parallel-group, non-inferiority study in healthy adults with self-reported and clinically diagnosed DH. After an initial lead-in period, subjects were randomized to either the Test (n = 150) or Comparator dentifrice (n = 154) and instructed to brush twice daily for the next eight weeks. DH was assessed at baseline and following four and eight weeks of dentifrice use by response to a tactile stimulus (tactile threshold) and evaporative (air) stimulus (Schiff sensitivity score and 100 mm visual analog scale [VAS]). The non-inferiority margin was defined as 6 mm on the VAS.

Both dentifrices were associated with statistically significant reductions in DH from baseline after four and eight weeks' use for all efficacy parameters (all p < 0.0001). There were no statistically significant differences between the groups. After eight weeks' use, the between-treatment difference in VAS scores was 2.67 mm (per-protocol analysis) in favor of the Comparator dentifrice; the upper limit of the 95% confidence interval (CI) of the between-treatment difference in VAS scores exceeded the pre-specified non-inferiority margin of 6 mm (upper 95% CI = 7.4). The non-inferiority margin was also exceeded after four weeks. Both dentifrices were generally well tolerated.

The pre-defined non-inferiority margin of 6 mm was not met, thus it is not possible to conclude from the present analysis that the Test dentifrice is non-inferior to the Comparator. However, for all efficacy measures, a statistically significant reduction in DH was observed for both dentifrice groups. There were no statistically significant differences between dentifrice groups, suggesting that changing the source of fluoride from SMFP to NaF does not affect the overall efficacy of the dentifrice in alleviating DH.