Our spray is specially formulated to end plaque and tarter buildup, and the all natural ingredients kill harmful bacteria on contact. With your Pets mouth free from this bacteria breath becomes much fresher. It is not necessary to brush, but it will work faster if you follow directions and brush every 3rd to 4th day. That is why we say Spray for ease, brush for faster results. 450+ sprays per 2.2 oz. bottle.