Brushing teeth is a simple task, but lots of people brush their teeth incorrectly, either skipping around so much that they don't really clean anything,
or rubbing so hard that they actually damage their teeth and gums.

No matter how good you try to brush your teeth, some bacteria will always be left behind.
The growth of dental plaque starts again the moment you stop brushing your teeth and remove the toothbrush from your mouth.

You should be very careful to use proper toothbrushing techniques so that the percentage of bacteria left behind will be the lowest possible.
Ask from your dentist or dental hygienist to teach you the correct tooth brushing technique.