I have a recommendation for you! I used to go to Clarendon Family Dentistry before I moved out of the area (born-and-bred Arlingtonian living in NYC now) and have only had great experiences. Friendly staff, attentive, etc. Used to see Dr. Lakas here, but he has since retired. Offices are right next to the Clarendon Metro, and I used to Metro to them when I was living in the District.

https://www.clarendonfamilydentistry.com