Be a good example and start their oral care early. Don't wait until they have teeth to start their oral care, do it from infancy by wiping the mouth and gums, then start brushing the mouth and gums with silicone toothbrushers until the first tooth erupts, then introduce a bristle toothbrush. Early oral care is key to compliance, and routine acceptance in children. Then you are brushing and training them in oral care routines until around age 5. Don't hand over the oral care routine to a child younger than 5, they cannot brush their own teeth well enough before this age and sometimes even later than that. It is the parents responsibility to brush their child's teeth and then when they are able to have more independence, the parent still needs to directly supervise every brushing.