Your target is a walk and a train ride, not a radius
A circle drawn around your address is a driving concept, and it will spend a large share of the budget on people who have no practical way to reach you.
Radius targeting assumes the patient gets in a car. Here they walk, or they take one train, or they change trains once and decide it is not worth it. A three mile circle around a Chelsea address includes people who would never make the trip and excludes commuters who pass your door twice a day.
Build the target from the places patients actually come from instead. Neighborhood and ZIP level targeting, weighted so the blocks around you get the most, adjacent neighborhoods less, and everything else nothing unless there is a reason.
Set location settings to people in or regularly in your area rather than the default that includes people merely interested in it. Left alone, that setting buys clicks from other states, and it will not tell you it is doing it.
Then check the location report every month. Not the summary, the actual list of places clicks came from. The waste in a dental account is almost always geographic before it is anything else.