Laboratory evaluation of dentin tubule occlusion after use of dentifrices containing stannous fluoride

The purpose of this study was to examine the effect of desensitizing dentifrices containing stannous fluoride (SnF₂) on dentinal tubule occlusion. Two experimental dentifrices with the same ingredients but different SnF₂ concentrations (Group II, 0.4% w/w; Group III, 0.454% w/w) were used; distilled water was used in the control group (Group I). Third molars were collected from Japanese and American dental patients. The crowns were removed and sectioned to obtain dentin discs, which were further cut into quarters. Thirty-six specimens each from Japanese and American patients were divided into three sets (n = 12 each) and assigned to each of the three treatment groups. The specimens were brushed for 10 s twice per day for 4 days. After treatment, the discs were observed by scanning electron microscopy, and the extent of dentinal tubule occlusion in the images was expressed on a five-point categorical scale. Group II and III specimens from Japanese and American patients showed greater dentinal tube occlusion than those from Group I, but the differences were not statistically significant. The present results suggest that both SnF₂ concentrations mitigate dentin hypersensitivity, regardless of patient ethnicity.