Modern Education of dental students is mainly performed through dental simulation units. These units make it possible for the students to learn the working sequences close to a realistic clinical situation. A fundamental part of this education is the skill to prepare teeth for prosthodontic treatment. The main priority is the capability to measure and to evaluate the preparation in a standard way. The aforementioned ability is an indispensable requirement of a successful and responsible clinical activity. With the help of a new electronic device - PREPassist - should students be better prepared to meet these requirements. It consists of a computersystem with which it is possible to present the preparation in a three dimensional way and consequently to measure it. It is possible for the students to evaluate the quality of their preparations in an interactive, objective and reproducable way by themselves. So the learning process is thought to be easier and the learning time shorter. It is going to be examined in which way and how much the quality of dental education will be improved using this system. The evaluation of the PREPassist is a cooperate project of the Departments of Prosthodontics of the University of Tuebingen and Freiburg. This study is financed by the Ministry of Science, Research and Art of Baden-Wuerttemberg. Keywords: dental education, preparation, prostethics, digital imaging, quality, technology