Do I have a malpractice case against a dentist who was negligent in telling me I swallowed an instrument?

I swallowed a one inch long metal post while receiving mild sedation at the dentist. Was not informed about the fact that I swallowed it till two days later when I returned for the second part of the dental work. Dentist said that I shouldn't worry about it at the second visit and did not provide me with a script for an xray till a few weeks later when I returned to finalize the dental work. I did not get injured from the object passing through me but there was obviously potential for it to. Is this medical malpractice? He was certainly negligent in telling me about it. When I asked him when he had known about it, he did admit that he knew before I left the office the first time.