Young children are not able to clean their own teeth. As a parent, you must do it for them when they are very young and do it with them, as they get older.
You should start cleaning your child's mouth even before your child has teeth. It gets both you and your child into the habit of keeping the mouth clean, and it gives baby (or primary) teeth a clean place to come into. The goal is to wipe all parts of the gums and teeth.
Cleaning your baby’s teeth
The best kind of brush is soft, with rounded bristles. It should be the right size for your child's mouth. You will need to buy a new toothbrush at least every 3 or 4 months.
Children can be hard on toothbrushes. If the bristles get bent or worn down, they will not do a good job, and may hurt your child's gums.
Should my child always brush right before bed?
Yes. If you don't get rid of the germs (bacteria) and sugars that cause cavities, they have all night to do their dirty work. Plus, when your child is asleep, he or she does not produce as much spit (or saliva). Saliva helps keep the mouth clean. So brushing at bedtime is very important.
How to brush your child’s teeth (Age 2 and up)
How to Floss