I asked 4 up-to-date dentists I know - here is what each said:
"The jury is out on whether there is any benefit to pre-dental care antibiotics more than 12 months after a joint replacement unless the person had a post-surgical infection or is immunocompromised."
Dentist #1 said "I advise my patients not to take unnecessary antibiotics."
Dentist #2 said "I leave it up to the patient to decide."
Dentist #3 said "I require that my patients take antibiotics unless they have adversely reacted to them in the past. It is a single dose a couple times a year, so I feel the risk is small. I watched my Mom struggle with an infected hip implant. It was awful."
Dentist #4 said "If you want to be my patient, take the antibiotics. Mouths are full of germs, and dental work often opens up wounds so those can get into your blood. Better safe than sorry."
My orthopedic surgeon agrees with Dentists 3 & 4 - I take antibiotics before dental work.