HELP PLEASE - fresh fruit causing tooth decay?

[catkinq]

we have just been told that ds (7) needs at least one of his adult teeth taken out and has holes in many of the rest. May need anothe rout (. The dentist said "no sweets, fizzy drinks, fruit juice etc". The problem is that he doesn't eat sweets, has never had a fizzy drink, does not eat biscuits, cake etc (just v occasionally - ie once or twice month maybe) and only has fruit juice with meals. He just eats loads of veg and pasta but does eat a lot of fruit (several bits a day). This was all the dentist could think was the problem.
Has anyone else come across fruit causing this kind of bad tooth decay? He only has fresh fruit (not dried). I'm now stuck as to what to give him, esp at school as they hand out free fruit and do not allow any other snacks.

I think eating some cheese after something sweet is supposed to help protect the teeth in some way?
I sympathise, my DS has yellowing front teeth and I feel very upset about it. This can only be caused by breast milk and/or fruit, DS doesn't like cheese either. I think it comes down to genes too, poor teeth run in my family so I am very careful DS's teeth

How awful for you. How about getting him always to brush his teeth after snacks/meals?

The dentist said specifically not to brush after eating fruit as the acids weaken the enamel and it stays weak for half an hour or so. She said just to eat fruit with a meal or to eat it at most once a day (as much as you like at once bu tall at once). This is why we are now stuck as to what to guive him as snacks but cheese is a good idea.