Feather margins can be effectively managed with our CEREC system. I prefer them for conservatively prepared anterior teeth and posterior onlays when the margin is mid-tooth at the height of contour.
The value of a feather margin is tooth conservation and optimizing aesthetics. When using a thinner e.max margin style, particularly with HT, there is natural shine-through influence of the cervical tooth color creating a very natural blend in the cervical half of the restoration. This approach will create a polychromatic appearance of a monolithic ceramic and a contact lens on the margin seam, making it hard to find following cementation.
Mill at 300 thickness with tradition left step bur (not the S-bur) and margin parameter at 120 to avoid chipping.
Final thinning of margin is accomplished after e.max crystallization with the Green Meisinger policing wheel (found in the James Klim DDS Meisinger lab kit JK03).
Listed below are the primary criteria for a softer margin style ceramic.