Once per week is recommended.  Clean the brush head after each use by holding it under a running tap. For Essence family toothbrushes, remove the nut from the brush head once a week and wipe away any residue you find with a soft cloth or paper towel. Run a damp cloth through the recessed area of the handle once a week and allow the handle to air dry. For other types of Sonicare toothbrushes, remove the brush head from the handle.  The charger base only needs to be cleaned periodically. To clean it, unplug the base then run a soft or paper towel along its surface. Never immerse the charger in water. Make sure the charger is dry before you plug it back into the socket. mild soap, water and a moist cloth are recommended for cleaning your Sonicare.