How does a new dental care policy typically work? How much does it cost? What does it cover?

Say I get a new dental care package. What does it typically cover? Could I get a policy and immediately use it for fillings. What is the cheapest dental coverage out there that covers fillings and cleanings? Is it economical and feasible to pick up a policy, carry it while you need it and then drop it?

Please tell me about your dental coverage experiences. Right now I went to a dental school, but I wanted to research my other option to make sure I'm making the right choice
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It depends on what strata you on, the lower ones dont pay for anything and the higher ones pay for more
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