A process and system for computer assisted orthopedic procedure is provided with a plurality of options to plan, execute, and monitor the creation of a cavity to receive a prosthetic based on clinical needs and pre-operative imaging data. A phantom made of materials of known densities is used to normalize CT image intensity values to estimate bone density. The process and system controls the speed, cutter engagement, orientation, and shape of the cavity so produced based on the normalized bone density values.