Interesting Case: Crown and Post Fall Out
While a 70 year old male was visiting from another country, his upper lateral incisor crown fell out along with a post. (The post was placed in the space where a root canal was performed.)
There are some complications when evaluating a crown that has fallen out. There are reasons it didn’t stay in.
It is necessary to evaluate if there is enough tooth structure to hold the crown. There is supposed to be 1-2 mm of tooth structure beneath the post to have a good chance of success. There was no such amount of tooth with this patient which increases the chance of crown and post complications.
A second point to look at is the health of the gum tissue and the level of bone. This patient has severe bone loss and the crown margin was placed deep in the root. That part looked fine, but this means that there was more crown than root. If the ratio of crown height to root height is too high, that is also an unfavorable situation.
A third point to consider is the length of the post. The post needs to have at least half way down the root, but not so thick that it weakens the root, making it prone to fracture. In this case, the post was favorable.
Cementing the Crown
My short term solution was to cement what he had. The last time he had it cemented it lasted only 3 months. The recommendation for him was to go back to his dentist in his country and talk to him about getting an implant for that tooth. He also needs a more definitive address of his periodontal disease. He will have to get his crown re-cemented frequently if his periodontal disease is not addressed. Further deterioration of his existing tooth structure adds to the situation.
One other note: when someone loses a tooth, there is a chance to have a dental bridge. However, this patient has enough periodontal disease that the teeth that support this do not have enough bone to support this dental appliance. This means that in a short period of time (a couple of years) the supporting teeth will loosen up and the patient could lose that also. So, that is not a recommended solution for this patient.