I think there is a genetic compontent to pre-disposition to tooth decay.

But enviromental factors will play a larger part.

I have never had a filling or any teeth work in my life, but all of my molars (so basically except for the bottom & top 6 or so), are still my baby teeth, (genetic, my mum has the same thing, born with only half of the second set.. freaky i know), so when i'm 40 or so the roots won't hold any longer and they will fall out, and i'll have to get inplants or something.

But the teeth i have are all in great condition. My mum has filings though, don't think my dad has any.

When should you take kids to the dentist to check their teeth are alright?