A Randomized Clinical Trial Investigating the Effect of Particle Size of Calcium Sodium Phosphosilicate (CSPS) on the Efficacy of CSPS-containing Dentifrices for the Relief of Dentin Hypersensitivity.

OBJECTIVES: To investigate the effect of reducing the particle size of calcium sodium phosphosilicate (CSPS) bioactive glass from ~14 µm (NovaMin®) to ~4 µm (Vitryxx®), and of changing the fluoride source in a 5% CSPS dentifrice from sodium monofluorophosphate (SMFP) to sodium fluoride (NaF) on the efficacy of CSPS-containing dentifrices in dentin hypersensitivity (DH) relief.

METHODS: A randomized, controlled, examiner-blind, five-treatment arm, parallel group, stratified, exploratory study of NaF dentifrices containing 2.5% or 5% small particle size CSPS (~4 µm), NaF or SMFP dentifrices containing 5% CSPS (~14 µm), and a regular fluoride dentifrice in healthy subjects with DH. Sensitivity to tactile stimulus (Yeaple probe) and evaporative (air) stimulus (Schiff Sensitivity Scale, visual analogue scale) was assessed at baseline and after one, two, four, and eight weeks' twice-daily treatment. The study was not statistically powered to detect significant between-treatment differences.

RESULTS: One hundred thirty-three of 134 randomized subjects completed the study. All treatments showed similar, statistically significant (p < 0.007) improvements in DH compared to baseline at Weeks 2, 4, and 8. No trends favoring any specific treatment were observed. Treatments were generally well tolerated.

CONCLUSIONS: The apparent absence of a positive treatment effect for the CSPS-containing dentifrices compared to the regular fluoride dentifrice is inconsistent with other previously reported efficacy studies for CSPS dentifrices.