I think in dentistry, a lot (if not most) of the procedures are not templated, so practitioners really find their own ways to perform these procedures. That is as long as the desired outcome would be achieved. Most of the time, patients complain about pain. Definitely, dentists would want to alleviate the pain, that's the common ground. But they would differ on ways on they will make the pain go away. Unlike in other medical fields, the standardization of procedure in dentistry is, in my opinion, quite poor. As they would say, there is no one way to skin a cat and that's pretty much how some dentists view it. As long as they could address the complaint, they'd go for it.

Not saying though that dental schools do not teach them to do the proper ways. What I'm saying is that as time pass by, dentists develop their "own" techniques to go about these procedures which are sometimes non-canonical as compared to what is written in peer reviews and books, simply because they think it works for them. But the downside is that of course risk is amplified.