My experience with dentists is that they're less about preventative care and more about expensive procedures. It's unfortunate that our health care centers are profit focused.
I don't mind profit motivation, but (at least in Canada) it's combined with all sorts of protections that lead to zero competition and dramatically different costs across jurisdictions (which is Provincial). I'm in Alberta and a lot of procedures from check-ups to fixes cost 2x as much as next door in BC. A few years ago I "shopped" some dentists looking for rough estimates on a general visit (with the provision I wasn't going to hold them to a quote, just wanted to know how much I should be prepared to spend) and most looked at me like I was crazy.
Profit-driven without competition is the worst of both worlds.
A family member is a health "insurance" actuarial. He said supply and demand does not work in health care. As an example of the ton of data insurance companies have demonstrating this, when a town/region has a higher number of dentists per person, prices do not go down, but that community's dental costs go up. Why? More procedures. And they tend to not get caught because when you get a 2nd opinion in the same town you have the same 'do more procedures' incentive. To have a chance of finding out, you'd have to get your 2nd opinion outside that region.
If 2 different dentists recommend different set of procedures (involved different teeth) - my understanding is that all these procedures are not needed and it is time to change both these dentists.
Plus the never-stated but not-quite-secret that uncontrollable factors like genetics and mouth chemistry dictate a lot of what's going to happen, regardless of how well you care for your teeth...
I think mouth chemistry is at least somewhat controllable, via what you eat. It'd be nice if dentists knew more about that aspect, so that they could advise about it beyond "don't eat too much sugar".