Fluoridated Milk Effect on Enamel and Dentin Caries In Situ

Objectives: This study analyzed the effect of frequency of intake and amount of fluoride (F) in milk on the remineralisation of artificial enamel and dentine caries lesions in situ.
Methods: Pre-demineralized bovine enamel and dentine slabs were randomly allocated into 5 groups. Twenty-three subjects wore removable appliances with 2 enamel and 2 dentine slabs for 7 days in each phase, following a double-blind, crossover protocol. Each treatment group comprised milk containing 2.5 ppm fluoride (F) everyday (T1), 2.5 ppm F every other day (T2), 5.0 ppm F every day (T3), 5.0 ppm F every other day (T4) or no treatment (control; T5). The subjects were instructed to immerse the appliances in 100 ml of milk for 5 minutes and then to drink 200 ml of the respective milk.
Results: Enamel alterations were quantified by surface hardness (%SHR) and transversal microradiography (TMR, ΔΔZ) and dentin by TMR only. Data were analyzed by repeated-measures ANOVA/Tukey´s tests (p<0.05). For enamel, the highest %SHR was found for groups treated with fluoridated milk every day compared to control, without significant differences between T1 and T3. All groups showed positive values of ΔΔZ, except for T4; significant differences were seen between T1/T3 and T4. For dentin, the only group that presented remineralization was T2.
Conclusions: Fluoridated milk every day seems to have higher remineralizing effect on enamel than its use every other day, but no dose-response effect was seen. Dentin, however, does not seem to benefit from every day use of fluoridated milk.