A 15-month-old child, equivalent to a child of 1 year and 3 months of age, should have began weaning from bottle feeding from 6 months of age. Tooth decay or dental caries are commonly associated with prolonged bottle feeding as the sugars and other substances in milk; when drank from a teat from a bottle; prolongs the exposure of teeth to the milk, leading to overgrowth of bacteria causing dental caries.