Experimental study on the inhibitory effect of baicalin on streptococcus mutans and demineralization of carbonated enamel

KONG Jing-jing; LIN Xiao-hui; ZHU De-chao; LI Chun-nian; ZHANG Yi

doi:10.19749/j.cn.cjgd.1672-2973.2025.05.001

Abstract：Objective To investigate the inhibitory effect of baicalein on enamel demineralization induced by the synergistic action of carbonated beverages and Streptococcus mutans,and to provide a scientific basis and reference for the pharmacological treatment of early caries in patients with carbonated beverage-related enamel demineralization.Methods Sixty enamel blocks(4 mm×4 mm×2 mm)were randomly divided into 3 groups(n=20):control group(Con group),S.mutans group(S.mutans group),and S.mutans+baicalin group(S.mutans+Bai group).Measure and record the microhardness values SMH0 of the three groups of samples before demineralization.Prepare artificial demineralization models with carbonated beverages,measure and record the microhardness values SMH1 of the three groups of samples after demineralization.Randomly select two enamel blocks from each group for scanning electron microscopy to observe the surface morphology of the enamel and detect the demineralization results.The samples with successful demineralization were treated with normal saline in the Con group,with Streptococcus mutans solution in the S.mutans group,and with Streptococcus mutans solution and baicalin solution in the S.mutans+Bai group.The microhardness of the samples in the three groups was measured,and 5 samples were randomly selected from each group for scanning electron microscope observation.The enamel specimens were stained with fluorescence and observed by laser scanning confocal microscope.Results After treatment with carbonated beverages,scanning electron microscopy showed that the demineralized enamel surfaces were rough,the enamel column structures were dissolved and destroyed,and SMH1 was significantly lower than SMH0(P＜0.05).After different treatments,SMH2 in Con and S.mutans+Bai groups were significantly higher than that in S.mutans group(P＜0.05),but there was no significant difference between Con and S.mutans+Bai groups(P＞0.05).Scanning electron microscopy showed that the enamel surfaces of S.mutans group were rough and uneven,with a large number of bacteria attached,and the enamel columns were broken,forming honeycomb-like depressions,holes and cracks.The pores on the enamel surface of S.mutans+Bai group became shallower or disappeared,and the bacterial attachment was less than that of S.mutans group.Laser confocal microscopy was used to observe the fluorescence staining of enamel abrasive sections.The S.mutans group had the most fluorescent dye deposition,a larger fluorescence area and higher intensity.S.mutans+Bai group had less fluorescent deposition,and the fluorescence area and intensity were lower than those of Con group(P＜0.05).Conclusion Carbonated beverages can cause tooth enamel demineralization,and Streptococcus mutans exacerbates carbonic acid-induced tooth enamel demineralization.Baicalin can slow down the demineralization of tooth enamel and the early progression of caries by inhibiting the growth and reproduction of Streptococcus mutans.