I'm sorry to hear about your situation! I would recommend seeing your dentist as soon as possible. If it was just the crown/ that fell off, the fix may be as simple as re-cementing it. However, if it truly was the abutment that broke off, there may have been a defect in it. Hopefully the dentist/lab honors their work and replaces it for you. If the implant body is still integrated into your bone and remains stable, there should be no need to replace the implant itself- just the abutment. The process of replacing the abutment (and crown) should take no longer than 2 weeks, but it could likely be rush delivered (by the lab) in a week's time. In the meantime, save the piece(s) that fell off and bring them with you when you see your dentist. Best of luck!
