| Objective 1 To observe the sealing effect of the bioactive glass with different concentrationson on dentinal tubules, in order to get the optimum concentration for the treatment of dentin hypersensitivity. 2 to compare the sealing effects on dentinal tubules and mechanical friction resistance of sealing effect of bioactive glass and three desensitizers. To provide experimental basis for treatment of dentin hypersensitivity by bioactive glass.Methods 1 25 hypersensitive dentin discs were made from fresh isolated third molars, and randomly divided into 5 groups(n=5). Group A to D were treated with 1%, 2%, 3%, 5%bioactive glass solution for 2min, and then immersed into the artificial saliva for 24 h, The models of group E were immersed into the normal saline. Then observe the sealing effects by SEM. 2 SEM observation: 50 hypersensitive dentin discs were made from fresh isolated third molars were randomly divided into A, B groups. Each group has 25 dentin discs were randomly divided into 5 small groups(n=5), then were treates with 3%bioactive glass(Group A1 and B1), 75%Na F glycerinum(Group A2 and B2), GC Tooth Mousse(Group A3 and B3), Deionized water(Group A5 and B5) for 2min, Group A4 and B4 were coated with Hybrid Coat, then all the discs were immersed into artificial saliva, the total treatment would last for 7 days separately except group A4 and B4. Group B were treated with brushing teeth, each test piece every time 3 min, 8 times a day, last for 2weeks. observe the sealing effects of the dentinal tubule by SEM. Group A1, A2, A3, A5 were analysised by the X-ray energy spectrum analyzer. Methylene blue penetration test:40 hypersensitive dentin models were made from fresh isolated third molars,and randomly divided into 5 groups(n=8), then were treated with 3% bioactive glass(C), 75%Na F glycerinum(D), GC Tooth Mousse(E), Deionized water(G) for 2min, group F were coated with Hybrid Coat, all the specimen were immersed into the artificial saliva for 24 h,then were immersed into methylene blue for 6h, fixed by 10% formaldehyde, teeth were opened longitudinally and divided into two parts along the median line, observe the penetration depth of methylene blue.Results 1 The sealing effects on exposed tubule of the bioactive glass with different concentrationson were in the order of 3% bioactive glass solution(plugging rate98.26%) > 5% bioactive glass solution(plugging rate 88.8%) > 2% bioactive glass solution(plugging rate 76.49%) > 1% bioactive glass solution(plugging rate 73.63%)(P<0.001). 2 All of the desensitizers could significantly block the exposed tubules. The sealing effects on exposed tubule of five groups were in the order of bioactive glass(plugging rate 100%) > 75%Na F glycerinum(plugging rate 95.34%) > GC Tooth Mousse(plugging rate 90.07%) > Hybrid Coat(plugging rate 89.16%) > Deionized water(plugging rate 70.37%%)(P<0.001). After brushing test, the sealing effects on exposed tubule of five groups were in the order of bioactive glass(plugging rate 99.29%) >75%Na F glycerinum(plugging rate 83.04%) > GC Tooth Mousse(plugging rate79.53%) > Hybrid Coat(plugging rate 78.35%) > Deionized water(plugging rate 71.42%)(P<0.001). Methylene blue.test showed that bioactive glass exhibited the best sealing ability, then turned to 75%Na F glycerinum, GC Tooth Mousse and Hybrid Coat. Deepest dye penetration of bioactive glass group was 0.60 mm, and 75%Na F glycerinum group was 0.68 mm, and GC Tooth Mousse group was 1.40 mm. and that of Hybrid Coat group was to the pulp chamber.Conclusions 1 The bioactive glass solution with a mass fraction of 3% is the optimum concentration for the treatment of dentin hypersensitivity. 2 The results showed that four desensitizers could sealing dentinal tubules and significantly reduce the permeability. The effect of sealing dentinal tubules is best especially with bioactive glass; bioactive glass shows a better ability on resisting to mechanical friction than the three desensitizers. |
PDF Full Text Request