Beyond treating your dog’s bad breath, which is often the first sign of poor dental health, teeth brushing removes plaque buildup caused by leftover food and bacteria. If this plaque is not stopped in its tracks, it hardens and can lead to further oral health problems, such as broken and cracked teeth, and other adverse results in the body if the bacteria enter the bloodstream. Tartar (aka hardened plaque) is comprised of 80% bacteria and can damage the gumline, bone, and ligaments that hold teeth in place.