The best way to avoid needing major dental work done while you're breastfeeding is to take very good care of your teeth while you are pregnant. (newhealthadvisor.com)
If you have to have major dental work done while breastfeeding, you will want to know any pain medications that will be okay to take after the procedure. (newhealthadvisor.com)
I have a friend who's 3 year old had to have major dental work b / c of the bottle of formula at night. (amotherinisrael.com)