In Situ Abrasive Effects of an Experimental Low Abrasive Dentifrice

Objectives: To compare the abrasive wear of an experimental low abrasive dentifrice on human dentine with an experimental ultra-low abrasive dentifrice, a higher abrasive daily use whitening dentifrice and water, as reference controls, using non-contact profilometry in an in situ model.
Methods: This was a single-centre, single-blind, randomised, split-mouth, four-treatment, two-period, crossover, in situ study in healthy subjects who wore two intra-oral buccal appliances, lower left and lower right, each fitted with four dentine specimens. Appliances were worn for approximately 5–7 hours each treatment day, but removed for ex vivo treatment 3x/day and during lunch. Treatments were: an experimental low-abrasive 1% alumina/5% sodium tripolyphosphate (STP) dentifrice (relative dentine abrasivity [RDA] ~40); an experimental ultra-low abrasive 0% alumina/5% STP dentifrice (RDA ~13); a whitening dentifrice (RDA ~142) and water (RDA ~8). Dentine loss was assessed using non-contact profilometry for dentine specimens removed after 5, 10 and 15 days treatment.
Results: Twenty-nine subjects were randomised. The higher abrasive dentifrice group showed the greatest dentine tissue loss at all timepoints, followed by the low abrasive dentifrice, the ultra-low abrasive dentifrice and water (3.89 ±0.382 mm, 2.48 ±0.382 mm, 1.35 ±0.375 mm, and 1.29 ±0.390 mm respectively at Day 15). Between-treatment differences were statistically significant at all timepoints post-baseline (p<0.05) for all treatment comparisons except between the ultra-low abrasive dentifrice and water.
Conclusions: Use of an experimental low abrasive 1% alumina/5% STP dentifrice resulted in significantly lower dentine tissue loss in situ compared to a commercially-available higher abrasive whitening dentifrice. There was no significant difference in dentine tissue loss following use of the experimental ultra-low abrasive dentifrice compared to treatment with water alone. All products were generally well-tolerated. This study was funded by GSK Consumer Healthcare.