Even though they are temporary, your child’s baby teeth are important to helping him or her develop a healthy smile both now and in the future. Children need strong and healthy teeth to chew their food, speak, and help their permanent teeth come in correctly. So it’s important to protect baby teeth from cavities and other decay.
One common cause of children’s cavities is the misuse of baby bottles after a child’s teeth come in. When a baby falls asleep with a bottle, the liquid in it can slowly drip onto their teeth all night long. The prolonged exposure to sugar in the liquid leads to cavities and decay. Infants should finish their bottles or drinks before bedtime and naptimes to avoid this, and children should start drinking out of cups as soon as possible to avoid sucking on a bottle.
Since baby teeth are key to a healthier life-long smile, baby bottles should never be filled with soda, sports drinks, or other unhealthy sugary drinks. Parents can help with their child’s dental hygiene by wiping infant gums with a clean, damp gauze pad or washcloth. As soon as a child’s teeth come in, brush them gently with a child-size toothbrush and a smear (or grain of rice sized amount) of fluoride toothpaste until your child is three years old.
When your child’s first tooth appears, talk to your dentist about scheduling the first dental visit. Treat the first dental visit as you would a well-baby checkup with the child’s physician. Remember: starting early is the key to a lifetime of good dental health.
Sourced from http://www.mouthhealthy.org/en/az-topics/b/baby-bottle-tooth-decay