DS is 20 months old and I brush his teeth 2x a day. He was excl. breastfed to 6 months and now bf 4 - 5 times a day.
According to my dentist, I should cut down on my DS's breastfeeds as breastmilk is bad for teeth 
She did not look at DS's teeth, I was the one having a check-up, I just asked here whether what I was doing with DS's teeth was the right thing.
I didn't want to quote the research at her which says quite the opposite: bm does not cause caveties if you have good oral hygiene and in fact bf gives a child an excellent jaw line and perfect bite, etc.
DH's has 3 close relatives who are dentists, all have PhD's, and every single one of them says that bf is excellent for teeth (but they are based abroad not in the UK).
So, here goes my question:
Do you have a toddler/older child who was exclusively breastfed for at least 6 months, and then breastfed to at least 2 years old, who has lots of caveties ?
Have you been told these caveties are due to extended breastfeeding ?