I can't get my two yr old off bottle.

Shelby
He is six mo away from turning three. He's a very smart boy and he's my world. His bottle seems to be a comfort thing for him. I've tried every cup. Bottle steps. I even put coke in cups and he chooses bottle with juice. Idk what to do. His teeth are starting to rot up top where the bottle lays. I brush teeth constantly I don't want him to have silver teeth.