Stain control with two experimental dentin hypersensitivity toothpastes containing spherical silica: a randomised, early-phase development study

AIMS: To determine in human participants whether toothpastes containing small quantities of a novel spherical silica, added to provide enhanced cleaning properties, could achieve similar or greater extrinsic dental stain removal compared to toothpastes containing standard dental abrasive silica concentrations. MATERIALS AND METHODS: One hundred and twenty-three adults with extrinsic dental stain were randomised to one of four parallel groups for 8 weeks’ twice-daily brushing with an experimental toothpaste containing either 0.5% or 1% spherical silica (with relative dentin abrasivity [RDA] of ~38 and ~58, respectively), or marketed toothpastes containing either 6% (RDA ~ 36) or 16% (RDA ~ 166) standard abrasive silica. The objective was to evaluate the ranking order in extrinsic dental stain removal at Week 8, as measured by MacPherson modification of Lobene stain index Area × Intensity. RESULTS: Small treatment differences were observed between toothpaste formulations. The ranking order in extrinsic dental stain removal was: experimental 1% spherical silica toothpaste >16% standard abrasive silica toothpaste >6% standard abrasive silica toothpaste >experimental 0.5% spherical silica toothpaste. Toothpastes were generally well tolerated. CONCLUSION: This early-phase development study suggests that toothpaste formulations with low concentrations of a novel spherical silica abrasive with high-cleaning capability are generally well tolerated and appropriate for further development.