I haven't heard of too many docs working evenings, not many civilian dental practices are open late. There is a clinic by Ft Campbell where the Ft Campbell dentists moonlight that some guys worked evening though.
It might be somewhat difficult to find a practice that will even hire a military doc, due to only being able to work a few days a month. I would guess that there is at least one practice near each base you could get hired for a few saturdays a month and on days you can take leave.
The experience of military docs moonlighting probably greatly depends on the practice they moonlight at. Four Captains, including me, have moonlighted here at Ft Riley at the same practice during the last two years. Two quit, one is currently deployed, and I still work there until I head to endo school this summer. It is a bad place to work, as the owner is the worst dentist you could possibly imagine, you wouldn't believe some of the stories I could tell you. I have no idea how this guy has a license. I routinely replace fillings he placed a year ago that are now failing because he doesn't use rubber dams and fills everything with flowable composite. Also several of the assistants are lazy and since I only work occasionally they don't care if they do a good job assisting me or not. The front desk ladies never give me enough time and are always squeezing in emergencies, so my days there are exhausting and stressful. The only good thing about the place is that the owner rarely works on the days I work, so I don't have to put up with him and I don't have anyone telling me what to do like I would on the Army post. The only reason I am still working there is because during my civilian endo residency I won't be able to moonlight, so I am trying to save up some money for the next two years. I had about 50 days of leave saved up, so I am working two days a week there for several months until I head to endo school.
So my moonlighting situation isn't the greatest, but hey, maybe you will find a great place to work. It has made me appreciate having adequate time for procedures, ample supplies, and good assistants at Ft Riley. I thought that private practice would be so much better than being an Army dentist, until I saw how bad private practice can be. The grass is always greener I guess... Thanks for letting me vent, I feel better now