Baby bottle tooth decay is caused by the frequent and long-term exposure of a child's teeth to liquids containing sugars. Milk, formula, fruit juice, sodas, and other sweetened drinks are examples of common liquids that are culprits of this type of decay. It is advised to never allow children to fall asleep with a bottle containing milk, formula, juice or other sweetened liquids.
Giving an infant a sugary drink at nap or night time is harmful because during sleep, the flow of saliva decreases, allowing the sugary liquids to linger on the child's teeth for an extended period of time. If left untreated, pain and infection can result.