I was just talking about this a few months ago. In my opinion, single-payer dental insurance should be provided before health insurance. If a country has single payer but provides no dental insurance, it's a waste, as a lot of issues start in the mouth. We're at the forefront of a lot of this right now (as well as gut health).
In insurance, you win, and are made whole when you are unlucky enough to suffer from a low-frequency, high-cost event.
With dental 'insurance', you always pay partially out of pocket, and as soon as you hit a (rather small) cap, you pay the rest entirely out of pocket.
It's not an insurance, it's a limited-access subscription service.