If I were you, I would let the kid have the bottle. My oldest son had his till HE was ready to give it up. Bottles, especially if they are filled with milk, are a comfort for babies and toddlers. So I wasn't going to take a comfort from him. He took juice and water out of a sippy but wanted his milk in a bottle. He gave his bottle up last December; he was 2.5 years old exactly. His teeth are perfect too. I had my bottle till I was 4 and my teeth are fine. And the AAP even says...
"Many mothers are bottle-feeding their children beyond age 2, even though pediatricians often recommend the bottle be given up by 12 to 18 months, according to a California study of 191 healthy full-term infants.
Researchers found 42 percent of 2- to 3-year-olds were fed about three bottles a day, and 16 percent of 3- to 4-year-olds were given an average of 2.1 bottles a day."
at 10:57 AM on Mar. 15, 2010