Abstract:

BACKGROUND: Fluoride nano-hydroxyapatite has acid resistance, which is similar to the composition of tooth tissues. The fluoride nano-hydroxyapatite has good biocompatibility and has functional characteristics of remineralization on enamel.
OBJECTIVE: To observe the closed effect of fluoride nano-hydroxyapatite on dentinal tubules.
METHODS: Fifty-six healthy extracted teeth were randomly divided into four groups: fluoride nano-hydroxyapatite, nano-hydroxyapatite, sodium fluoride and blank control groups. Materials in each group were used to coat outer dentinal tubules twice on every morning and evening respectively (2 minutes/time), and then were saved in artificial saliva in a 37 ℃ thermostat. The teeth were longitudinal split as immediate group at 7 days after experiment. Teeth were longitudinal split again as wear group which using deionized water to simulate daily brushing 100 times on experimental area. Experimental area of dentin surface, blocking rate and closed depth of the section of dentinal tubules were observed using scanning electron microscope.
RESULTS AND CONCLUSION: The dentinal tubules were open fully in the blank control group. Scanning electron microscope results showed that sealing effect of the dentinal tubules in the fluoride nano-hydroxyapatite group was better than that in the other three groups. Sealing effect of the dentinal tubules in the immediate and wear groups were fluoride nano-hydroxyapatite > nano-hydroxyapatite > sodium fluoride. It is indicated that blocking effect and sealing depth of the fluoride nano-hydroxyapatite are higher than those of the nano-hydroxyapatite and sodium fluoride.