Crown and post is loose and falling out, can this be replaced?

From my experience, once a post fails the best long term option is to now move to a dental implant.  Replacing the post will not be a good permanent option most of the time.  Good luck.  

Hi:Depending on the fit of the crown and post and if there is no decay, the crown and post can either be recemented or replaced.Best,Dr. Maddahi

thanks for your questions . Unfortunately without examining and seeing the tooth I am unable to answer this question. When a post is loose it can sometimes be cemented but like I said without an evaluation I would not be able to give you a clear cut answer . I would seek care from a dentist in Philadelphia to determine what the best course of treatment you would need 

Whether or not you can simply replace a post and crown after it has come depends on several factors that only seeing a dentist can answer.
If there is a cavity or fracture of the remaining tooth may not make it practical or possible to recement it.  If it has come out one or more times in the past, it may be time to come up with a better solution.  
If it can be replaced, ideally it should be placed back with a bonding cement that can help keep it in more securely.  
Good luck!