Like health insurance plans, dental insurance plans are usually categorized as either Indemnity or managed-care plans (Dental PPO plans fit in this latter category). Put broadly, the major differences concern choice of dental care providers, out-of-pocket costs and how bills are paid. Typically, Indemnity plans offer a broader selection of dental care providers than managed-care plans. Indemnity plans pay their share of the costs for covered services only after they receive a bill (which means that you may have to pay up front and then obtain reimbursement from your insurance company).
Managed-care plans typically maintain dental provider networks. Dentists participating in a network agree to perform services for patients at pre-negotiated rates and usually will submit the claim to the dental insurance company for you. In general, you'll have less paperwork and lower out-of-pocket costs with a managed-care dental plan and a broader choice of dentists with an Indemnity plan.