The New Zealand Dental Association wants all sugary drinks banned at school.
Spokesperson Dr Rob Beaglehole said it was not uncommon for dentists to remove teeth from 18-month-olds because they had been drinking sugary drinks out of baby bottles.
The association says a can of Coke has nine teaspoons of sugar in it, while the World Health Organisation recommended a daily sugar intake of six teaspoons per day.
What many parents don't realise is that fruit drinks are also not good for young children. They are acidic and sugary and cause the enamel in teeth to dissolve.
Apple juice and orange juice have an acid level of between 3 and 4 on the pH scale according to the Ministry of Health, slightly less acidic than vinegar and similar to wine. Carbonated soft drinks and sports drinks are even more acidic.