Should I make her parents pay?

My son has been being bullied really bad by this girl at his school. The school has done nothing about it. Like they ever do anything about bullying 😒. She's been pushing him and has hit him. He's not a violent person so he doesn't hit people back. They are in the 6th grade so its not like they don't know better. I'm gonna be honest. I've told my son if things continue and nothing is being done always defend yourself in the end. Regardless of the gender defend yourself. But he's a lover not a fighter so he won't. She pushed him when he was walking through the hallway and he fell down the stairs. One of his front teeth got knocked out and the other went up into his gums. I was losing my shit in the principles office. Her parents were trying to defend her saying "Oh well she was just playing." Should I make them pay his dentist bill because I'm fucking pissed. I haven't decided yet.