The Effect Of Sodium Bicarbonate Solution On The Acid Resistance Of Human Enamel And Remineralization Of Early Caries: An In Vitro Study

Objective:The purpose of the study is to investigate the effect of sodium bicarbonate solution on the demineralization and remineralization of early artifical caries.Methods:The enamel specimens were divided randomly into four groups,each of which was exposed to 0.12mol/LNaF mineral solution,1mol/LNaHCO3 mineral solution,mixed mineral solution of 0.12mol/LNaF and 1mol/LNaHCO3 and double-distilled water respectively. The hardness of the surface of each sample was measured with microhardness tester,before and after mineral solution immersion and artifical caries formation.Using KaVo DIAGNOdent,to detect lesion depth of the enamel samples,the highest values on surfaces of preremineralization and postremineralizalion were recorded respectively.The morphological difference of enamel surfaces were observed after anticaries and remineralization test by scanning election microscope (SEM).Results:â‘ After three mineral solution application,the hardness of the enamel surface were increased. The difference between preexperiment and postexperiment were significant(P<0.01).After artificial caries formation test,the hardness of experimental groups and control group were decreased.The effect of inhibition of acid solubility in artificial caries after mixed mineral solution treatment is significantly greater than the other two experimental groups(P<0.01).There were not significant difference between NaF group and NaHCO3 group(P>0.05).â‘¡After remineralization,the highest values of three experimental groups were decreased.The results were significantly different between pretreatment and posttreatment.There was not statistical difference in the control group(P>.05).Compared mixed mineral solution group with the other two experimental groups respectively,the decreased rate of the highest value had significant differences (P<0.01).There were not correlation between NaF group and NaHCO3 group(P>0.05).â‘¢In the SEM,local holes and irregular type of destruction were found in control group after anticaries test,less demineralized areas and different degree deposits were observed on enamel surfaces of the experimental groups which were pretreated with three kinds of mineral solution.There was lest destruction in the mixed mineral solution group.After reminerlization test,characteristic enamel erosion was observed in the control group.The surfaces of three test groups had a more regular,smoother appearance than control group.Mixed mineral solution treated lesions showed more regular globules of deposits than other two test groups.Conclusion:â‘ There is certain acid-resistant effect using sodium bicarbonate to pretreat the dental enamel.The anticaries effect of fluoride may increase when combined with bicarbonate.â‘¡Bicarbonate solution can promote the demineralized enamel to be remineralized.The effect of remineralization on artificial caries is enhenced by the synergistic action of bicarbonate and fluoride.