• Siriporn Chotipaibulpan
• Supathra Amatyakul
• Chonlada Rattanawiwatpong
• Chalida Nakalekha
• Piyanuch Chanchanglek

Objective  According to the hydrodynamic theory, anything that decreases fluid movement across dentine should cause a decrease in dentine sensitivity. This study was to investigate crystallization of desensitizing agents in dentifrice on dentinal tubule.

Materials and methods  24 extracted molars were longitudinally sectioned to expose the dentine. The specimens were divided into 6 groups; 1 control group (n=4) and 5 experimental groups (n=4 for each group). In control group; specimens were not brushed, but were soaked in distilled water. The specimens in each experimental group were brushed twice a day for 2 weeks (n=2 for each group) and for 4 weeks (n=2 for each group) with dentifrice containing different desensitizers as followed: brand 1 with no desensitizer, brand 2; containing 5% KHO₃ and 0.45% SnF₂, brand 3; containing 5% KHO₃ and 0.80% MFP, brand 4; containing 5% KHO₃ and 0.24% NaF, brand 5; containing 10% SrCI₂.6H₂O. All specimens were examined by a scanning electron microscope to evaluate size, amount and morphology of crystals occluding dentinal tubule and peritubular dentine.

Results  The results appeared to show that all dentifrice produced some occlusion on tubule with the level of coverage and occlusion varied between products. Of all the experimental groups; brand 2 produced crystal-like structures which occluded the highest proportion of the tubule. Whereas brand 3, 4 and 5 produced a higher level of occlusion than brand 1. More amount and larger size of crystals were found in 4-week groups compared to 2-week groups.

Conclusion  The dentifrice containing desensitizing agent produced a higher level of dentinal tubule occlusion than the dentifrice with no desensitizer.

(CU Dent J 2002;25:71-9)