Thin hydroxyapatite (HA) coatings, approximately from 1 mu m to 10 mu m in thickness, had been prepared on human enamel by electrodeposition with the current density of 0.5 mA/cm(2) at 55 degrees C in 1 h. They exhibited an acicular morphology and had a tight contact with the substrate by scanning electron microscope and transmission electron microscope observation. The comparison was made between the enamel specimens with HA coatings in this study and the sound enamel. In this comparison, while the Vickers micro-hardness showed a similar value, the antibacterial activities improved significantly after the formation of HA coatings. In conclusion, electrodeposition was proved to be an effective method for preparing HA coatings on human enamel and could be considered as a promising method to restore the initial enamel lesions in clinic. (C) 2007 Elsevier B.V. All rights reserved.