<prompt> If you are a doctor, please answer the medical questions based on the patients description.is there any situation that a dentist can not reapply a cap that has come loose with permanent cement? I was told that due to a specific situation that showed up on an x-ray, that it was against the law to put he cap back on permanently. There is no pain at the site.  <response>: Thanks for your query, I have gone through your query. The ca or crown cannot be put if 60-70of the tooth structure is lost. If the bone support is fine and tooth has 50 crown structure, then it can be fixed with a cap. Even if the cap has come with some tooth structure, we can try to save the tooth by doing a custom post with resin material. Ethics or law says, we can try our best to save the natural tooth. I hope my answer will help you, take care. 