Ask your ceramist how he or she would like you to finish your preparations for all ceramic restorations. You might be surprised to hear that the preference is for a highly polished final preparation.
If you are doing feldspathic restorations or even if you are using milled cores or pressed ceramics, a highly polished surface is easier to work with than one with diamond bur marks throughout.
When you finish your preps go over all the surfaces with the appropriate carbide finishing burs and follow it with a brownie point. You can shape the brownie point to polish all finish lines by simply shaping it with a diamond bur. Run the brownie at low speed so that it doesn’t fly apart in the patient’s mouth.