Simulation is a vital part of the learning of restorative dentistry. It provides the student with motor and procedural skills that would be impossible to learning in any other way. However, in order to use preclinical simulation most effectively, its limits need to be understood. Discussion of these rarely appears in the literature. This article identifies some of the purposes of simulation found in more general literature on the subject, and applies these to preclinical dentistry. It also describes some of the limits to simulation in the teaching of restorative dentistry.