Most times a loose tooth can be saved.
That is if the tooth that is loose is not severely loose and only slightly loose.
If the tooth is slightly loose then it may be just fine as is and there's not too much a dentist can do to tighten up the tooth so you would just have to live with the loose tooth unless it's becoming infected.
If the tooth is really loose then there's no saving it and you can continue using that loose tooth as long as it stay in your mouth.
I've had a really loose tooth and the dentist said they couldn't do anything to tighten it up and they could pull it or I could just let it naturally fall out.
I decided to just let it naturally fall out and it did around 8 months later.
Also the dentist said that it was normal for some teeth to be slightly loose so if you have a slightly loose tooth then it's usually not a problem.