Improved mineralization of dental enamel by electrokinetic delivery of F(−) and Ca(2+) ions

This in vitro study evaluated the effects of the infiltration of F(-) and Ca(2+) ions into human enamel by electrokinetic flow (EKF) on the enamel microhardness and F(-) content. Sound human enamel ground sections of unerupted third molars were infiltrated with de-ionized water by EKF and with F(-) ion by EKF respectively. All samples were submitted to two successive transverse acid-etch biopsies (etching times of 30 s and 20 min) to quantify F(-) ion infiltrated deep into enamel. Remarkably, sound enamel showed a large increase in microhardness (MH) after infiltration of NaF (p < 0.00001) and CaCl(2) (p = 0.013) by EKF. Additionally, NaF-EKF increased the remineralization in the lesion body of artificial enamel caries lesions compared to controls (p < 0.01). With the enamel biopsy technique, at both etching times, more F(-) ions were found in the EKF-treated group than the control group (p << 0.05), and more fluoride was extracted from deeper biopsies in the NaF-EKF group. In conclusion, our results show that EKF treatment is superior in transporting Ca(2+) and F(−) ions into sound enamel when compared to molecular diffusion, enhancing both the mineralization of sound enamel and the remineralization of artificial enamel caries.