Efficacy of a desensitizing toothpaste containing arginine and calcium carbonate on dentin surface pore structure and dentin morphology.

PURPOSE: To investigate the laboratory changes in dentin tubule occlusion morphology during short term use of desensitizing products as evaluated by electron microscopy and an image analysis.

METHODS: Freshly extracted human third molar teeth were collected at random and 40 dentin discs were prepared. These dentin samples were then divided in to four groups (n=10). The test treatment consisted of undiluted Colgate Sensitive Pro-Relief Toothpaste containing 8.0% arginine and calcium carbonate that was applied on the dentin surface under a brushing cycle of 200 strokes, 2 times/day, for 10 days and then soaked in the filtrated human saliva. The two other test products were a commercial toothpaste, Sensodyne Original, containing 10% strontium chloride and a professional re-mineralizing treatment paste (GC Tooth Mousse). The negative control group was soaked in human saliva that had been sterilized by filtration. The occluding ability of the dentin tubules, using the dentin disc model, was evaluated using scanning electron microscopy (SEM). The degree of occlusion of the dentin tubules was quantified using an image analyzer and the results were analyzed by ANOVA and a Tukey's test.

RESULTS: All test products created a smear layer on the dentin surface that significantly reduced the diameter of dentin tubules after treatment. Compared to the dentin tubule area on disks treated with the negative control (72.02 +/- 7.23 microm2), disks treated with Colgate Sensitive Pro-Relief, Sensodyne Original, and GC Mousse had dentin tubule areas of 2.10 +/- 0.42 microm2, 10.11 +/- 2.83 microm2, and 30.40 +/- 4.04 microm2 respectively. These differences were statistically significant.