Regarding dental care: Is there a difference in quality of care received from a PPO provider than a Non-PPO?

My Delta Dental insurance provides a 60% co-pay for Non--PPO and an 80% co-pay for a PPO dental care provider. And are the allowed amounts that are set by Delta Dental different for a PPO and Non-PPO provider for the same procedure?
--------------------
PPO providers are usually paid at a lower rate than a non provider. Thus the insurance company can make more of a profit. That is why they pay less and you have more out of pocket expense if you see one. It has nothing to do with their level of expertise. My personal opinion after practicing dentistry for over 40 years, is that most non providers are better dentists and have plenty of patients and do not need to get paid at a lower rate for their services. That is why they do not sign on as providers.
Source