In situ randomised trial to investigate the occluding properties of two desensitising toothpastes on dentine after subsequent acid challenge

The aim of the study was to determine in situ the relative abilities of two desensitising toothpastes to occlude dentinal tubules with or without acid challenge.

The study design was a single centre, randomised, split mouth crossover model examining four treatments over two periods. The primary outcome was the degree of occlusion proffered by two desensitising toothpastes [Sensodyne(A (R)) Rapid Relief (8% strontium acetate, 1040 ppm sodium fluoride) and Colgate(A (R)) Sensitive Pro-Relief(TM) daily (8% arginine, 1450 ppm sodium monofluorophosphate)], a standard toothpaste (1450 ppm sodium fluoride) and water, after acid challenge. Healthy adult volunteers wore bi-lateral lower buccal appliances each with two dentine sections, receiving two treatments per study period. Samples were brushed twice a day with treatment, with two additional 3-min extra-oral acidic challenges applied ex vivo on days 3 and 4. A secondary outcome was the degree of occlusion attained in the absence of acid challenge. Examiners blinded to the study assessed occlusion by visual score of post-treatment scanning electron microscope images.

All 28 participants completed the study. In the absence of acid challenge, occlusion scores for both desensitising toothpastes were similar and significantly better than control scores (p <0.02). After acid challenge both desensitising toothpastes occluded more effectively than controls; however, occlusion scores for the strontium acetate paste were significantly greater than those of the arginine paste (p <0.02).

The occluding properties of the strontium acetate toothpaste were significantly more robust after acid challenge than those of the arginine toothpaste.

Patients with hypersensitivity, regularly imbibing dietary acidic drinks, should be advised that Sensodyne(A (R)) Rapid Relief provides robust tubule occlusion despite repeated acidic challenges.