Dental work is not exactly the most exciting thing to spend Hawaiian-vacation-caliber money on. When it comes to pricetag anxiety, expensive dental work is right up there with roof repair, plumbing work and taxes: All things we know are necessary, but hope we don't end up with an unexpected bill for today. Alas, that day comes for all of us. And that's when you want to know the ins and outs of how, exactly, your dental insurance works. Or dental insurance plans, plural, if you're covered by more than one plan at the same time. It can get confusing quickly in these cases, and you might find yourself wondering which insurance is considered primary, which is secondary, or what that even means. That's why we've answered six common questions about dental insurance, including details on primary and secondary insurance, to help you through the process.