The present study was undertaken to investigate the mineral uptake in fluorosed enamel in vitro. Bucco-lingual sections of severely fluorotic teeth were exposed to a mineralizing calcium phosphate solution supersaturated with respect to hydroxyapatite and under-saturated with respect to other calcium phosphates in order to favour apatite formation. The solution was renewed once a week, and concurrently the sections were washed in a hypochlorite solution for 30 sec or 5 min to prevent bacterial growth. The experiments were continued for 14 weeks at a temperature of 23 °C. The results of the experiments were evaluated chemically by changes in the liquid phase, and histologically by qualitative and quantitative imbibition studies in polarized light. A limited mineral uptake was demonstrated both chemically and histologically. By prolonging the hypochlorite treatment from 30 sec to 5 min an increase in mineral uptake was recorded