Easy-to-use refill. When your mentadent pump is empty, simply remove the empty cartridge and insert the refill. It's easy, clean and convenient! The baking soda & peroxide reaction: in a dual-chamber dispenser, baking soda & peroxide are kept separate. When you brush, the two sides react & release powerful oxygen bubbles. Bubbling action cleans between teeth & along the gum line, killing germs & leaving your mouth refreshingly clean. Kills Bacteria Removes Plaque 2 refills better value!