Effect Of Bioactive Glass Combined With Gallnut Tannic Acid On Early Enamel Caries Of Deciduous Teeth

Objective: This experiment takes deciduous teeth as the research object to study the effect of bioactive glass(BAG)combined with gallnut tannic acid on remineralization and inhibition of remineralization of early enamel caries in deciduous teeth and to look for a safe and efficient remineralization drug for demineralization of deciduous teeth.Methods: 90 deciduous anterior teeth pulled out due to retention of deciduous teeth were adopted.The enamel surface was smooth and had a good development without demineralization by visual observation.Carbonated beverages were used to establish the demineralized tooth model.90 samples were randomly divided into five groups(n=18).Negative control group A: artificial saliva;Positive control group B: Duraphat;Experimental Group C:6%BAG solution;D: 1% gallnut tannic acid solution;E: 6% BAG solution combined with 1% gallnut tannic acid solution.The five groups of samples were carried out a treatment of remineralization for twenty days respectively.After the whole experiment was ended,Vickers microhardness tester was used to measure the microhardness values of each group before demineralization,after demineralization and after remineralization.Scanning electron microscope was used to observe the mineral deposition on enamel surface.Laser confocal microscope was used to observe the deposition of fluorescent dyes in each group after remineralization.After the remineralization experiment was completed,the samples of every group were put into carbonated beverage again for demineralization for 15.After the whole process,biochemical analyzer was used to detect the calcium ion concentration in the demineralized beverage solution.Results: 1.After five groups of samples were carried out a treatment of demineralization by carbonate beverages for twenty days,the microhardness values of the five groups of samples were all lower than that before demineralization(P<0.05).However,there was no significant difference between each group(P>0.05);Compared with that after demineralization,the microhardness values of the five groups of samples were significantly improved after they were carried out a treatment of remineralization(P<0.05).There was no statistical difference between group B and group C and there was statistical significance between other groups(P<0.05).Group E had the highest microhardness value.Scanning electron microscopy showed that enamel had slight scratches in individual locations before demineralization.However,the great mass of enamel surfaces were smooth and flat.After demineralization,the enamel surface appeared obvious concave and porous structures.After remineralization,mineral deposits with different degrees can be seen in all groups.Laser confocal microscope showed that the penetration of fluorescent dye reduced with different degrees after the sample was carried out the treatment of demineralization.Group E showed that fluorescence area was the smallest and fluorescence intensity was the weakest.2.After the five groups of samples were treated by the cycle of demineralization,remineralization and remineralization,biochemical analyzer was used to measure the dissolved amount of calcium ions in demineralized liquid.The results showed that there was statistical significance between the every two groups except group B and group D(P<0.05),A>C>B=D>E.There is the lowest concentration of calcium ion in the demineralization solution of group E.Conclusion: The joint application of bioactive glass and gallnut tannic acid has the best effect on remineralization and inhibition of remineralization of early enamel caries in deciduous teeth.