A toddler’s teeth may rot if he’s allowed to drink milk throughout the night, not just before sleeping but all night long. The baby teeth bathe in milk sugars, which rot them away. If you catch the decay early enough, you can save the teeth, but if not, they must be extracted so the rot doesn’t spread to the adult teeth waiting below the gums. The extraction generally involves sedation or even anesthesia, since toddlers don’t open wide willingly.
I’m sure you can see why you’ll want to avoid the need for such measures. To prevent tooth rot, you must not feed your child breast milk or formula during the night. Even if you could brush the kid’s teeth all day long, it wouldn’t prevent the rot if you were still feeding at night. In my experience, a last bottle, or nursing before sleep, won’t cause tooth rot.
The problem is that feeding is usually related to sleeping disturbances, meaning that if you remove the bottle or refuse to nurse, you’ll have a very angry toddler. If this describes your situation, please refer to the SLEEP entry to learn how to deal with a difficult sleeper.
Now let’s clear up another important issue. In certain books and Web sites that preach breast power, you’ll read that only bottle feeding is responsible for tooth rot in toddlers. Because of this fallacy, I have seen dozens of mothers unhappily surprised to discover their breast-fed kids’ teeth rotting. Don’t be misled. Breast feeding is great, and everyone agrees on that, but all-night feeding sessions can predispose a toddler to tooth decay, whether bottles or breasts are involved [See: Breast Feeding].