THE EFFECT OF EXTREMELY LOW-FREQUENCY (ELF) ELECTRIC-FIELDS ON BIOMINERALIZATION INVITRO

A device producing an extremely low frequency (ELF) electric field by capacity coupling was constructed, based on an especially designed power supply which could generate tetragonal electrical pulses at different frequencies between 40 and 6000 Hz. For field intensities exceeding 30 V/m, generally a strong retardation was observed on the crystal growth rate of hydroxyapatite and calcite. The kinetic coefficient of the growth rate law, measured by the constant supersaturation technique, changes in the presence of the ELF field. Different crystal growth rates were observed when different frequencies of the field were applied. This observation is consistent with previous observations which showed that the effect of the ELF field on the double layer of the suspended particles is frequency dependent.