Are there Dentists who can work on Alzheimer's patients?

I am not aware if there are any dentists that specialize in geriatric dentistry. Most have dealt with so many situations, it may just be a matter of finding one who understands the behavioral issues. (my Mom has Parkinson's and most doctors have figured out how to deal with the tremors) Can her reg. doc prescribe a mild sedative before her appointments?
Is there a reason her dentist chose an implant rather than a partial? It takes such a long time for the implant to heal before the tooth is installed and the area has to be kept very clean.
What is her age?