Abstract: Objective The study was carried out to evaluate In Vitro occlusion effect on dentinal tubule orifice by smearing or transparent pressureswage application of bioactive glass desensitizer using FESEM. To provide rationale and evidence for strengthening efficacy of bioactive glass desensitizing treatment. Methods 56 dentin slices were prepared from extracted teeth and treated with 6% citric acid solution to demineralization, then dentin slices were randomly divided into 7 groups according to different treating methods and durations: smearing 1day group (A1), smearing 3 day group (A2), smearing 7 day group (A3), pressureswage 1day group (B1), pressureswage 3day group (B2), pressureswage 7day group (B3) and negative control group. Occlusion effect was observed in dentinal tubule orifice in each group via Field emission scanning electron microscope (FESEM). Result FESEM results indicated that dentinal tubule was well occluded after smearing or transparent pressureswage application of bioactive glass desensitizer. Apparent mineral deposition was observed in dentinal tubule. Dentinal tubule exposure rates were A1(6.29±1.18)%、A2(3.40±0.84)%、A3(1.23±0.43)% 1、3、7 days after smearing method. Dentinal tubule exposure rates were B1(5.31±0.97)%、B2(1.4±0.30)%、B3(0.36±0.15)% 1、3、7 days after pressureswage method. The difference of dentinal tubule exposure between A1and B1 was not statistically significant (p value=0.42). While differences of exposure in A2/B2 and A3/B3 were statistically significant (p value=0.007 and 0.013). In negative control group, dentinal tubule was open with clear border and dentinal tubule exposure rate was (19.11±1.27)%. Conclusion transparent pressureswage method can improve occlusion effect of bioactive glass desensitizer in a short period of time. Compared with smearing method the improvement is significant.

Key words: bioactive glass, remineralization, transparent pressureswage method, field emission scanning electron microscope