This is how you should really brush your teeth

“Two minutes at least is ideal, 30 seconds for each quarter of the mouth,” she said. “And at least twice a day.
"You should wait at least 30 minutes after eating to brush the teeth, otherwise the acid can damage the tooth surface," he said

“Before bed is most important as we have reduced saliva flow when we are asleep. Saliva would usually help naturally buffer the acids in the mouth. Read More