What is the cost of removing dental implants?

Hi d672gm,To answer your question, it depends on where the implant are located, how intricate the procedure is to remove them.  Depending on the examination, there are procedure out there that can save your mother from potentially having a skin graft,  an examination with comprehensive X-rays are needed to make a proper diagnosis and give you a detailed treatment plan.  See an expert for a second opinion if needed.  ( see link below)

Dental implants can be removed in a few different ways.  The least invasive way to remove a dental implant is with a dental implant retrieval tool.  With this tool, there is no bone removed when taking out the implant.  Other ways to remove dental implants are by trephining (drilling around) the dental implant.  The issue with trephining out a dental implant is that bone is removed and it is a more invasive procedure.
To answer your question, the cost for removing a dental implant is about $500-600 per implant.  That would not include bone grafting, sedation costs, etc. 
I hope this helps!