I think you need to find someone who is very knowledgeable about your specific insurance provider. Perhaps in some instances the insurance company might be willing to pay for composites but not for inlays or onlays, even if inlays or onlays make the most sense. Perhaps with some plans crowns might be paid for(or partially so) but not inlays or onlays. It would not be a good circumstance if one needs to choose a composite or a crown to have it covered if the best option is an inlay or onlay.