Tooth decay is not a hard thing to understand.
Sugars from sweets, fruit, milk, etc etc etc etc get into
The bacteria, naturally occurring in the mouth, ingest the sugars.
The bi-product of this bacteria - sugar combination is acid.
The acids eat your teeth.
Soooo, the take home point here is this........
The longer you have sugar in your mouth the more chances there
are for the bacteria to produce the acids that cause decay.
Time + Sugar = Decay
One of the saddest manifestations of this is Baby Bottle tooth decay.
Little tikes that get put to bed with a bottle.
They will drink a little, fall asleep, wake up and drink a little, then fall asleep.
The result is that they have sugars on their teeth, essentially, all night long.
Feed your little ones with a bottle if you so choose.
But then after that make sure to brush their teeth.
Or, at very least, give them a drink of water to help rinse the sugars away.
Getting your 2 year old to obey you is tough.
Getting them to sit still while I drill on their severely decayed teeth ......