An in-situ study investigating dentine tubule occlusion

Objectives: This study investigated the dentine occlusion properties of dentifrices developed to treat dentine hypersensitivity; one containing 8% Strontium Acetate, 1040ppm Sodium Fluoride (Sensodyne® Rapid Relief) and the other containing 8% Arginine, Calcium Carbonate, 1450ppm Sodium Monofluorophosphate (Colgate Sensitive Pro-Relief® ) to a control paste (1450ppm sodium fluoride) and water. The influence of a dietary acid challenge was also investigated. Methods: This clinical study was a single centre, randomised, crossover, single blind design. Twenty-eight healthy participants wore two intra-oral appliances each retaining four dentine samples for two periods of four days. Samples were power brushed twice daily with test products and subjected to an agitated acid challenge on days three and four. Samples were removed daily for scanning electron microscopy (SEM) and graded on a categorical visual scale.  Results: On days one and two, strontium acetate and arginine-based dentifrices demonstrated significantly better dentine tubule occlusion than both water and control paste:

After three and four days of twice daily brushing with acid challenges on days three and four, the strontium-based dentifrice demonstrated significantly better dentine occlusion than all other treatments (p<0.0001). While tubule occlusion was maintained for the strontium-based dentifrice following acid challenges, a statistically significant loss of tubule occlusion was observed for the arginine-based dentifrice (p<0.0001). Conclusion: Both strontium acetate and arginine-based dentifrices result in statistically significant dentine tubular occlusion compared to controls, but the arginine-based dentifrice is more susceptible to acid challenge. This study was supported by GlaxoSmithKline Consumer Healthcare.