Abstract:

BACKGROUND: Various methods for closing dentinal tubules and reducing fluid flow in dentinal tubule have different treatment effects.
OBJECTIVE: To observe the occlusion effect of (NH4)2SiF6 solution on dentinal tubules, and to determine the possible mechanisms underlying (NH4)2SiF6 solution in dentin hypersensitivity treatment.
METHODS: Twelve free dentinal discs were made from free third molars, and divided into four pretreatment groups. The teeth were soaked in pretreatment solution for 2 minutes, namely 0.29 mol/L EDTA, 6% citric acid, 50% citric acid, and rinsed ultrasonically with deionized water 20 minutes, respectively. Every above-mentioned group was randomly assigned into experimental group, control group and blank group, respectively. The teeth of three groups were treated for 3 minutes by experimental solution, namely 0.476 mol/L (NH4)2SiF6, 2.36 mol/L Ag(NH3)2F solution and physiological saline, respectively. The opening on the dentinal tubules before and after treatment was observed using scanning electron microscope. The constituent ratio of fluorine, silicon, silver, phosphor and calcium distributing the premolars surface was analyzed by the photoelectron spectrometer.
RESULT AND CONCLUSION: Under scanning electron microscope, the opening area of dentinal tubules significantly decreased after the (NH4)2SiF6 and Ag(NH3)2F solution treatment; the sediments formed dentinal tubules contained silicon, calcium and phosphorus, presented as a complex of calcium phosphate silicon following (NH4)2SiF6 treatment, dentinal tubules remained open state after Ag(NH3)2F solution treatment and showed various levels of sediments on surface; there were significant differences in dentinal tubules open area between two kinds of fluorine-containing drugs treatments. The results suggest that the occlusion effect on dentin tubules is significant by using (NH4)2SiF6 solution, and reduced with reducing pH value of pretreatment solution.