The most damning comment I've ever gotten out of a dentist when dealing with the obvious malpractice of another was, "Well, that's not how I would have done it, but philosophies vary.". This wasn't merely fear of being sued by the subject of criticism. Dental associations routinely prohibit criticism of peers. If a dentist honestly assesses the bad practices of their peers to a client, they could lose their job before any of those they criticize.

People need to realize this. Good dentists often can't call out bad ones without shouldering significant risk to themselves. You have to pay attention to what your dentist is doing and get a second opinion when it seems appropriate. That second opinion should be as independent as possible. Preferably from a different clinic, and the dentist should not be informed of the previous opinion. If they know they're contradicting another dentist, they may play it safe.