3 year old/fillings/laughing gas?

Laughing gas is actually really bad for the female reproductive system. Most dentists don't use it anymore, so I'm surprised your child's dentist does. It order to get her to let the dentist do his thing, you gotta make it worth her while. Bride her with something, so she'll cooperate. The gas really helps you relax, so once she gets it, she'll probably relax and be fine.