In vitro study of dentin remineralization by synergistic action of strontium chloride and bioactive glass
Objective To study the effect of synergistic action of strontium chloride and bioactive glass on dentin remineralization in vitro.Methods Forty-four human isolated maxillary third molars were selected,and dentin sensitivity models(32 squares+12 analogous rounds)were prepared and randomly divided into four groups for different treatments(n=11),namely,control(distilled water),strontium chloride,bioactive glass,and strontium chloride+bioactive glass groups.7 days later,analogous rounds samples were used for the characterization of remineralizers by X-ray diffraction(XRD).Four square samples from each group were analyzed by scanning electron microscopy(SEM)to observe the sealing of dentin tubules on their surfaces and vertical section,and by X-ray spectroscopy(EDX)to analyze the major elemental compositions and calcium to phosphorus ratios of the remineralized substances.The remaining four square samples from each group were etched with 6％citric acid and then scanned by scanning electron microscopy(SEM)to observe the sealing of dentin tubules on their surfaces and vertical section in order to evaluate the acid resistance of the remineralized substances.Results Dentin tubules were closed to different degrees in the strontium chloride,bioactive glass,and strontium chloride+bioactive glass groups,with therate of dentin tubule closure in the strontium chloride+bioactive glass group(90.72％),which was significantly higher than that in the bioactive glass group(80.71％)and the strontium chloride group(55.38％).Except for the control group,remineralized substances were found in dentin tubules of each group.There were different degrees of opening and decrease in the closure rate of dentin tubules in each group after acid treatment.The closure rate of dentin tubules in the strontium chloride+bioactive glass group and bioactive glass group were 66.67％and 58.66％,respectively,which were higher than that in the strontium chloride group(41.58％).Except for the control group,remineralized substances were still found in dentin tubules of each group.X-ray spectroscopy analysis showed that the main elements detected in each group were calcium,phosphorus and oxygen,and there was strontium in the strontium chloride group and strontium chloride+bioactive glass group.But the difference in calcium-phosphorus ratio between the groups was not statistically significant(P＞0.05).X-ray diffraction results showed that strontium hydroxyapatite and hydroxyapatite characteristic diffraction peaks appeared in the remineralized material of both strontium chloride and strontium chloride+bioactive glass groups,and hydroxyapatite characteristic diffraction peaks appeared in the remineralized material of the bioactive glass group.Conclusion The synergistic effect of strontium chloride and bioactive glass significantly increased the sealing rate of dentin tubules,and the main element composition and calcium-phosphorus ratio of the remineralized materials formed were similar to those of natural dentin.The acid resistance of the strontium chloride+bioactive glass group and the bioactive glass group were the same,and better than that of the strontium chloride group.
NETL
NSTL
万方数据
