A.S.
I had the same problem with my little guy. I'll tell you that the sooner you get rid of the sugary drink - the better!!! My 4-yr-old has crowns on all 8 of his back teeth. I feel SO guilty for not changing this very bad habit sooner. When he started having dental problems, we went straight to water at bed time. At first it was difficult, but he soon learned it was water or nothing. I gradually put less and less water in the cup until he was down to a sip of water after he brushed his teeth for bed.