When utilizing CAD/CAM systems to design and manufacture dental prostheses and occlusal splints, one soon wonders: How accurate is virtual occlusion? Conventional methods involving dental impressions, plaster casts, articulators, and manual verification tools such as articulating paper have well-known sources of error and error chains, and tried and tested error-handling strategies for many of them already exist. Digital workflows, on the other hand, are still very new and unfamiliar to some dentists. Besides digital processes such as intraoral scanning and optoelectronic jaw motion tracking, analog processes may also be required. The penetration of maxillary and mandibular dental models is one aspect of digital dentistry that immediately attracts attention. Virtual penetration occurs because digital technology, like every measuring system, is subject to measurement error, and because virtual reality can only approximate the true variable nature of the physiologic masticatory system. The present article aims to identify and discuss variables that affect the accuracy of virtual occlusion. Some errors are first discovered in the digital world. Virtual capabilities open up new perspectives that have yet to be explored and understood.