The link below is to a ratings site designed by the very smart people at PLZ. For better or for worse user reviews are gaining in power. You can think of online reviews as e-word of mouth. If you haven’t done it recently check your google local listing. Any reviews? Are they positive? How about YELP?
I have often googled a dentist in another city for various reasons and found negative user reviews; reviews I expect the dentist did even not know existed. On the other hand some dentists take active steps to facilitate positive reviews. Check it out.