How do define "debate"? When someone disagrees with you ,I guess they are debating whereas when you disagree with them you are not debating .In other words you have the bottom line . Is this because you are a dentist or scientist or just smarter than everyone else?
If Walter Clifford has analyzed dental material and determined their exact structure, there is no reason he can't disclose the information to the public.
Many insurance companies cover fillings and crowns but not lab manufactured onlays ,so dentists are more likely to suggest crowns.