How do bacteria live in your mouth after brushing your teeth?

Brushing: It's impossible to brush away all the bacteria. The environment is perfect for them to grow and they reproduce very quickly so it's a constant battle. Just like we can't kill all the flies in the world.

Always there: Bacteria are hearty and can live in very inhospitable environments. There are still bacteria remaining in your oral cavity after brushing, flossing, and mouthwash. You must brush 2 to 3 times a day to keep the bacterial population down to a healthy level. You will never be able to remove all the bacteria in your mouth.