Tooth decay in infants and very young children is often referred to as baby bottle tooth decay.
Baby bottle tooth decay happens when sweetened liquids or those with natural sugars (like milk, formula, and fruit juice) cling to an infant's teeth for a long time.
Bacteria in the mouth thrive on this sugar and make acids that attack the teeth. At risk are children whose pacifiers are frequently dipped in sugar or syrup.
Giving an infant a sugary drink at nap time or nighttime is particularly harmful because the flow of saliva decreases during sleep.