As a former dental technician, let me tell you that the best way to find a good dentist is to call or visit local dental laboratories and ask THEM. They deal with many dentists and can tell by the work sent to then which dentists are generally good, which are generally mediocre, and which are generally BAD.
They are a better source than even patients are, as patients opinions are often influenced by if he’s ‘a nice guy’, if he hurts, and what his prices are. A lab will know the actually quality of his work.