Infants and young children can have a much higher risk of tooth decay if they frequently are put to bed (for a nap or for the night) with a bottle containing juice or milk. The sugars pool around the infant’s teeth as they sleep, letting bacteria produce acids that wear away at the tooth enamel. To prevent this, avoid putting your child to bed with a bottle of anything other than water and wipe their gums and teeth with a damp washcloth or pad of gauze after each feeding.
Sippy cups should only be used for a short time to help infants transition from a bottle to a regular cup. Do not let your child carry around a sippy cup full of anything other than water during the day. Juice, milk, or other liquids with sugar can quickly grow bacteria that increase the chance of cavities.