You should generally brush your teeth for 3 - 5 minutes max. As long as you brush your teeth the right way once, you won't need to brush it anymore through out the day. (That's what my dentist told me today) You should also floss and clean the linings of your gum. That's the most important part of taking care of your teeth. Once tarter gets in between your gums and tooth, your tooth is going to start to decay. Also, I learned, bacteria lives in the back of your teeth (molars) because bacteria does not like air. That's why you never really see yellow or a lot of plaque in the front of your teeth. Because the front of your teeth has a lot of access to air when you talk, laugh, eat, etc... So spend the time flossing and cleaning between the gums