IN VITRO EFFICACY OF DIFFERENT DESENSITIZING TOOTHPASTES ON DENTINAL TUBULE OCCLUSION: Dentinal tubule occlusion and depth of penetration of toothpaste

Dentinal hypersensitivity is a common complaint encountered by dentists. In this study, we aimed to assess the efficacy of selected desensitizing toothpastes on the percent of dentinal tubules occluded and the depth of dentinal tubule penetration in order to select the best toothpaste to treat dentinal hypersensitivity. Thirty extracted healthy human premolar teeth were used to prepare 60 dentin blocks with a uniform dimension of 2 mm x 5 mm x 5 mm each. The blocks were divided into 4 (1 control and 3 test) groups, each consisting of 15 samples: 1) saliva control group (CG), 2) Apagard Premio toothpaste (AP), 3) Tooth Builder toothpaste (TB) and 4) Elsenz toothpaste (EZ). The tested toothpastes and control were applied to the respective dentin blocks for two minutes twice daily for 15 days. Postapplication, all dentin blocks were examined with scanning electron microscopy (SEM) to detect the percentage of occluded dentinal tubules and the depth of penetration at 2000x and 1500x magnification, respectively. SEM revealed the AP group caused a significantly (p <0.001) greater (mean ± SD) depth of penetration of tubules (200 ± 15 μm) than the EZ (145 ± 26 μm), TB (94 ± 9 μm) and control (0 ± 0 μm) groups. In summary, all the tested commercial toothpastes were significantly more effective in occluding and penetrating dentinal tubules than the control and AP toothpaste had a significantly greater percentages of tubules occluded and a deeper penetration depth of dentinal tubules than the TB and EZ groups. Our results suggest AP toothpaste is likely to be more effective in treating dentinal hypersensitivity than the other tested toothpastes. Further in vivo studies among human subjects are needed to test this hypothesis.