In the US it is the same. The result is many people do not have dental insurance, and even if you do it often doesn't pay for much. Even our medicare (for old people) doesn't cover it. Thus some people cynically refer to teeth as "luxury bones".
For private dental insurance yes. It almost never makes sense to get private dental insurance and it’s almost always better to pay out of pocket.
I mean think about it from the insurer’s point of view. The only reason you’d ever get “the platinum” dental plan is if you were planning to use it. And it isn’t like you have that many “dental emergencies” if you have healthy teeth. If you don’t have healthy teeth you’d already know it when you pick out the insurance plan, so of course you’d get the upper tier.
The only scenario where it makes sense is if your employer picks up a healthy portion of the premium, in which case you are basically getting dental care subsidized by your employer. In that case you’ll likely come out ahead because you knew in advance pretty much how much dental care you’d need.
The same goes for vision care, really. You know in advance how many contacts, glasses and eye exams you’ll need. It isn’t really an insurable thing. If your employer pays for most of the premium, it’s employer subsidized eyewear & contacts for you!
…of course the math does change a bit when you have to pick the same type of plan for a family. In that case it’s time to bust out a spreadsheet and do the math to see the optimal course.
It's also tax-payer subsidized (i.e. regressive, because it's mostly higher-income people that get dental insurance) because it's money from your employer that you or your employer don't have to pay taxes on.
