The virtual proximal and occlusal grinding features are still evolving in the 4.0 software.  The new video posted in the CEREC 4.0 Integration chapter will illustrate the best way of negotiating the Virtual Grinding Tool features. View webcast 

Contact virtual grinding of the proximal and occlusal contacts are located in the Tool Wheel or Side Panel Tool pop out window and will now work for all proposal options, including BioCopy. The operators preferred Proximal Contacts Strength and Occlusal Contacts Strength parameters will dictate the virtual grinding firmness.