Please have a complete and well explain answer !! I will upvote

Paul had a terrible toothache while he was at work. He went to a dentist's office near his workplace. Although Paul had never been to that dentist before, the dentist was able to see Paul without an appointment and fixed the problem that caused the toothache. As Paul was leaving the office, the receptionist handed him a bill for $60.00. Paul refused to pay, claiming that no contract existed requiring him to pay.

Question: Is Paul correct? Why or why not?