What do you look for in a dentist?

I've been putting it off for a while (not that I haven't had enough other doctors to see), but now I absolutely have to get to the dentist.  It's been a couple of years since my last visit, and I wasn't happy with the work my dentist did at that time, so I'm looking for someone new.  What do you look for in a dentist?  At a minimum, I need a cavity filled.  Most likely, it's going to be at least one wisdom tooth extracted, maybe more.  Is there such a thing as a dentist specializing in patients with chronic health problems?  Anyone who would be familiar with immune suppressed patients?  The last thing I want is to be put on antibiotics or pain killers that will interact with my other meds or make my Crohn's worse.

You can tell a lot by the questions they ask and from their staff. I just discovered a great dental office. Several things they did stood out:
- they took a full medical history
- reconfirmed my meds/med history even when I came back for the 2nd time in a month
- gave price quotes ahead of time for major work
- they didn't rush to do fillings/invasive procedures, some things they would note and watch
- the dentists had good relationships w/ the hygeinists, but were still very particular in how they did things
- new equipment and protective gear-- goggles and masks
- they didn't use me as a tray for their tools while they worked
- they walked me back to the counter after and shook my hand
- they asked how I did w/ the topical anesthetic and went out of their way to make me comfortable

My previous dentist seemed to find cavities or the need for expensive work every visit. He always charged more than insurance, even for a cleaning and just generally seemed out to bilk me rather than care for me. The new place was so professional, careful and sincere that I'll never switch again.