I don't know about dentistry, but my mother is a doctor, and carried a very well supplied surgical suite when we were cruising. Everything from a sterilizer to hard core
narcotics. We traveled all over the Carribean, and never had a problem bringing them into any country. The most I can remember anyone looking at was asking to see her license
, and an ID.
She was always careful to ask the local doctor (if there was one) or headman for permission to work, and it was always granted. She was in such high demand we actually had to raise a 'doctors aboard flag' when she was treating people. Not the M flag, but one with "DOCTOR" on it flying when she was working.
Most of the pay was in tour guides, thanks, maybe fresh fish
or vegetables. But I think the thing she was most pleased to get was the look on someone's face when she was done treating them, and they realized that the pain/infection/problem was going to get better. She even did a tooth extraction for a guy who had never hear of a dentist, and couldn't have afforded the trip to see one anyway.