I discovered from this opinion that Delta Dental "is the state’s largest provider of dental plans." Maybe some readers have it.
Regardless, if you want to learn about the internal intricacies of this organization, Justice Banke lays them out in this 40+ page opinion. Suffice it to say that some dentists were unhappy about how they were paid, and sued, but lost.
In the meantime: Take care of your teeth.