I have a four tooth bridge and there is a hole under the side. What can I do and what are my options?

Please help, so worried. I have four tooth bridge and there is a whole under the side front anchor tooth . Not sure but I THOUGHT I heard a metal sound and a black item fall into the sink a few days ago. Could this have been a filling under the crown ? Im very sick with worry. My son was severely injured 4 years ago on p90x and I could not afford to attend to my needs. I knew I had a small cavity but it got much bigger.I need to be able to talk to his doctors and not be embarrassed. thanks so