I'm confused, did you have an accident that cracked your teeth in the last week? Also, dental places have payment plans, so I'm confused why you can't do that.

Also, he might need that money right now for something. I've paid put of pocket for trips while people said they would pay me back and it took months. Had I known I wouldn't have gone on the trip with them, as it meant I couldn't start school the next quarter, had to wait an extra quarter.

He isn't a loaner. He isn't a bank. Pay your debts when you say you will. You aren't entitled to his money. And you aren't entitled to him loaning you money. You are assuming he will and it makes you both look bad.