EFFECT OF DURAPHAT ON REMINERALIZATION OF ENAMEL AFTER DEMINERALIZATION:AN IN VITRO STUDY

Objective To simulate detal enamel decalcification after orthodontic treatment and evaluate the effect of Duraphat on remineralization using microhardness tester and scanning electron microscope(SEM). Methods Seventy-five premolars extracted because of orthodontic treatment were equally randomized to five groups as follows:group A,no any management was done;group B,demineralization was conducted;the teeth in groups C,D and E were immersed into artificial saliva after demineralization,the buccal surface of teeth in groups C and D were respectively applied with fluoride varnish and Duraphat as additional remineralization management before putting into artificial saliva.Microhardness of all samples was quantitatively measured by microhardness tester,and the data were statistically analysed.The morphology of enamel surface was observed by SEM. Results The value of microhardness in group A was the highest,that in group B was the lowest,that in groups D and E was higher than that in group C,the differences being significant(F=803.22,P0.05),the difference of that between groups D and E was not statistically significant(P0.05).SEM indicated that dramatic demineralization was observed in group B,and remineralization appeared in groups C,D and E,but the extent of remineralization was stronger in groups D and E than group C. Conclusion Duraphat has a remineralization action on demineralized enamel,but it has no more advantages than 1g/L fluoride varnish with regard to the results of remineralization.