Tooth decay from baby bottles is caused when a baby goes to sleep while bottle feeding.  When they are sleeping the flow of saliva is reduced and the natural self-cleansing action in the mouth is not working.  This causes teeth to decay rapidly.  Try to never put your child to bed with a bottle and wean him or her from the bottle at 12-14 months of age.  See a children’s dentist as soon as you see decay happening.  By the age of 1 your child should have his or her first dental visit.