Frequency of intake and amount of fluoride in milk for remineralisation of artificial caries on enamel and dentine: Ex vivo/in situ study.

OBJECTIVES: This study analysed the effect of frequency of intake and amount of fluoride in milk on the remineralisation of artificial enamel and dentine caries lesions ex vivo/in situ. MATERIALS AND METHODS: Pre-demineralised bovine enamel and dentine slabs were randomly allocated into 5 groups and fixed in removable appliances used by subjects for 7days in each phase. Each treatment comprised milk containing 2.5ppm fluoride daily (T1), or every other day (T2), 5.0ppm F daily (T3), or every other day (T4) or no treatment (T5). RESULTS: Enamel alterations were quantified by surface hardness recovery (%SHR) and transversal microradiography (TMR), and in dentine by TMR only. Data were analysed by ANOVA and Tukey's test (p<0.05). For enamel, the highest %SHR was found for T1 and T3 compared to control, without significant differences between them. All groups showed positive values of DeltaDeltaZ - T1 (247.3+/-198.5); T2 (110.9+/-303.2); T3 (226.0+/-299.2); T5 (5.0+/-288.0), except T4 (-274.5+/-407.3). For dentine, the only group that presented remineralisation was T2 (350.0+/-657.5). CONCLUSIONS: Fluoridated milk daily seems to have higher remineralising effect on enamel than its use every other day. Dentine, does not seem to benefit from daily use of fluoridated milk.