You really should brush your teeth in the morning, after each meal, and at night. It's even good to brush them after consuming a sugary treat so that the sugar doesn't stay on your teeth and cause cavitites. In the morning it's good to get rid of morning breath and your mouth just sat for 8 hours with just saliva. At night it's good because you're preparing for the night so that tartar and plaque cannot build up while you sleep/rest.
Hope this helps!
