I go to Gentle Dental in JP. I can safely say that Dr. Pezeshki is the best dentist I have ever been to. He actually cares, which is usually not the case. The hygienist also did a very thorough cleaning. I was impressed. At the time I had no dental insurance and had to pay out of pocket for a filling. And surprisingly it was very economical. http://www.yelp.com/biz/gentle-dental-jamaica-plain-3
Internal medicine I cannot help you with. I'm still looking for one.
I can also recommend Gentle Dental and Dr Pezeshki, he's by far the best dentist I've ever had and I have no problem going to the dentist anymore, because of him. Also can recommend Dr Tremblay at Harvard Vanguard in W Roxbury for internal medicine.