Dr. TungÕs Ionic Toothbrush will last indefinitely. However, the brush heads will not. You'll need the Ionic Toothbrush - Replacement Brushes - for that. These are two (2) original OEM replacement brushes for the Dr Tungs Ionic Toothbrush. Contains Two (2) replacement brush heads - for the Dr Tungs Ionic ToothbrushWith a wet palm or finger, lightly touch the metal band and then brush as normal. ... After brushing, rinse the Ionic toothbrush and store in a dry place to ensure maximum battery life. ... To replace brush heads, hold handle tightly and pull off brush head. Snap new brush into place over metal stem.