My dentist is in Somerville (https://www.smilesbyrosie.com) and still being careful with precautions - air filtering, often the window open, they're masked the whole time, masks expected in the waiting room, I'm only unmasked once I'm seated and they're about to do stuff with my mouth.

They are open to new patients, but as that says, triaging who gets priority.

I've had multiple hygienists there, they've all been good to great, and they're really good about listening to what helps the appointment go better.