It should tighten back up however it could be loose for another reason that you are unaware of. If you can I would go to the dentist and have it xrayed just to make sure it is ok.
I believe that an adult tooth that is loose will generally tighten back up on its own provided that there is no structural damage to the root or anything more extensive.
An xray of the tooth would be ideal to check the bone level surrounding the tooth and possible periodontal infection. If the bone level is low then the tooth may not tighten up but if it's an infection it gums will need to be cleaned out by a hygenist.
It's hard to say if it will or not. Are you sure it is really loose. It might just be that you are starting to notice that is it. If you are that concerned about it you should probably find a free dentist through public aid to help you.
Thanks. I believe it is tightening up. add a comment