SmileDirectClub Inc. hit Delta Dental with a pair of fraud lawsuits Tuesday, alleging a scheme by the country’s top dental insurer aimed at refusing to cover its web-based teeth-straightening treatments, even as the Covid-19 pandemic elevates the importance of teledentistry.

“Facing the prospects of having to pay millions in coverage claims,” Delta Dental and its affiliates “elected a profit-minded, bad-faith, unethical option,” the suits say. They “placed their bottom lines above the best interests of their insureds and above the language of their own policies.”

The virtually identical suits, filed in state courts in Chicago and San Francisco, target the…