It wasn't me, but I know the person who did it.
At the end of dental school, we all have to take National and State Board exams to insure that we are ready to practice dentistry on the public.
I know of a poor married dental school graduate that told a poor young man who needed a tooth restored that the would do it for free if he would be his patient for the state board.
The young grad got his patient to the clinic on time, gave him anesthetic, did the prep, made the impression, put a temporary on the patient and was getting ready to do the lab work and then said to his patient, 'We'll see you tomorrow". To that the poor young patient said, "Well, if you really want to see me tomorrow, you'll pay me $200 cash before I sit in this chair again"
The poor dental grad didn't have an extra $200 to spare, he had used everything he had to pay for the exam fee and to get everything he needed for the exam, ie... gold for the restoration, lab equipment etc... Back then $200 would be equivalent to approximately $900 now.
He assured the patient that he would find someway to get him the $200, because if the patient did not return, he would fail the exam. He told one of the examiners what had happened. The examiner asked the grad if he had the money, to which he replied, I think I might be able to scrape up $100. The examiner then pulled out his wallet and gave him $100 and said "I'll help you with this patient tomorrow." The grad then went to the lab and spent a few hours making the restoration.
The young man arrived on time the next day, He was handed two $100 bills and sat in the chair for the procedure. The Examiner took a 'special interest' in this dishonest patient and came over to assist the young grad.
The restoration was put into the mouth and was found to fit perfectly. But rather than just cement it in, the examiner asked the grad to numb the patient. Knowing there was no need to do this, but wanting to pass the exam, the grad was compliant, the patient didn't want to be numbed but he had heard the examiner so he submitted. About five minutes later the examiner came back to the operatory site and checked the young robber to see if he was numb. He asked the grad if he had a new carbide burr because he said there was one thing left to do before he could cement the restoration in place. The grad gave him the high speed handpiece with a brand new burr and the examiner took it and drilled right down the middle of the tooth, right into the nerve until it bled. Saying, "Now this will fit perfect", The examiner then placed a small dressing over the bleeding hole and told the grad to cement it with a wink. The cementation was checked, the grad was told that he had passed with flying colors this exam and the patient dismissed.
The examiner then told the grad, that young man will learn, you don't screw with a dentist. He'll either pay double that amount for a root canal in the next couple of weeks or end up loosing his tooth!
Yup, don't ever mess with a dentist. You will most definitely regret it in the end.