The only one that was worth it was a policy from Delta Dental. We went to sign up for it, and you were required to have a health plan through the ACA.
I have a wife and two kids. Three cleanings, a surface filling, and a sealant, was $800. This is our experiment going without dental insurance. We'll see how it goes this year.
Though I'm putting $600/month into the HSA since our health insurance through Honeywell sucks, and they have dropped dental. I'm waiting for them to drop health insurance.