The best way to know when it is time for a new brush is when it starts feeling stiffer. It is also recommended by dentist in Brampton for everyone to keep their toothbrush in an upright position so as not to contaminate the bristles with saliva and bacteria. When toothbrushes go bad, they will start to harbour bacteria between the bristles. If you brush with a toothbrush that is too short, then bacteria can enter the base of the toothbrush. Toothpaste also contains enzymes which help break down food particles and prevent them from lingering in between your teeth.