How would someone know if they still had infection in a tooth after a root canal? I'm asking because I had a root canal in december and had to take several rounds of antibiotics. I've been off them now for a month and seem ok. The root canal tooth is still sensitive like tender to pressure but otherwise fine. I do not have swollen glands but I notice an off and on pain in a gland, and my left tonsil appears swollen, and sometimes my ear hurts. I was wondering if this could all be caused from the infection I had, or could there still be one, or could the antibiotics have caused this? Any Dentists that can help please?