Sabbing on a baby bottle with fruit juice, syrup, drinking yogurt and other milk products, for example, can affect teeth. Because the teeth are in contact with sugars for long periods of time, there is a high risk of developing so-called baby bottle caries. At night, saliva can hardly recover the acid attacks on teeth. So in the evening and at night, a baby bottle is especially harmful. Starting at nine months, have your child drink from a cup instead of from a feeding bottle.