I think individual dentists will often go on anecdotal evidence. A single dentist may fix 10k+ teeth or more and treat the same patients over 20 years or more and is therefore often well placed to consider what worked in their practice.
This is often exactly what you want actually ... controlled trials typically can’t take into account enough useful variation in patient conditions to be a useful guide for any given patient. Meanwhile the dentists mental database can be ... if your dentist is a good one.
Anecdotal evidence is widely considered inferior to controlled studies, and for good reasons: Confirmation bias, survivorship bias, etc. are incredibly hard to avoid for a single person even if they're aware of them.
Anecdotal evidence doesn’t have to have any of those qualities but I do think that’s exactly right, yet most decisions just won’t have a basis in controlled trials due to the variation in the patient group and because you just can’t have controlled trials for most things .
For example, implant placement at a 45 degree angle are totally weird mechanically speaking given that the biting force runs down but dentists may do them to recruit better quality bone because they know that implanting into low density bone or calcious mass will likely lead to an implant failing but they just don’t see much failure due to weird angles ... this particular case happens so often actually that some companies now recommend placement at 45 degrees.
Personally experience, conferences, etc . It’s not how the world ought to work but it is how it mostly does.
This is often exactly what you want actually ... controlled trials typically can’t take into account enough useful variation in patient conditions to be a useful guide for any given patient. Meanwhile the dentists mental database can be ... if your dentist is a good one.