Yeah my dentist didn't have any problem with me still nursing, but she told me that if I continued to nurse at night it might be a problem for her teeth. She nursed her own children so she's very pro breastfeeding she just thinks that if your child has a tooth problem nursing at night is going to make it worse. She did tell me that she's had many parents that just get the dental surgery done and continue to night nurse. She has no problem with that either. She said it's the parents that continue to night nurse, but also refuse to have anything done to thier child's teeth.
Basically, when I was in there she said..
"I think it's great that you're nursing, but there might be a chance we could save her teeth (and not have to do surgery under general anesthesia) if you could stop night nursing." She gave me 3 months to use daily flouride treatments and try to night wean. Well, I tried, but not very hard. We did do the daily flouride treatments, but the night weaning just didn't go very well so we decided to just go ahead with the GA surgery and continue our lifestyle that we're comfortable with. This was the best decision for us. Ironically, my DD self weaned before we got to the surgery. I was 12 weeks pg and my milk dried up and she decided to stop nursing.