Nikos Mattheos1 and Anders Nattestad2 and Martin Schittek2 and Rolf Attström1,3

The Integrated Distributed Learning Environments or virtual classrooms constitute a new promising structure in education of health care personnel. A virtual classroom was developed aiming to teach periodontology to an international group of 28 dental students using a problem-based learning (PBL) approach. The course was web-based and included synchronous and asynchronous communication, on-line libraries and multimedia material. Students were organised in 4 independent groups and each group was appointed a tutor. The results of the study indicate that one of the most positive effects students experienced was competence in using the computer. They also rated highly the use of multimedia for learning of clinical procedures. It was found that web boards and email were too slow to allow group work in the virtual classroom. Real time communication programs were found to be superior for problem discussion and hypothesis formulation. However, email and the web board played a significant role during certain steps of the PBL method. The students expressed a positive attitude for the combined use of network-based learning and problem-based education. Our present experience suggests that distance learning should be organised with a mixture of different media, allowing communication of knowledge and skills between the resources and the students, as well as cooperation between the students. Computer literacy among teachers and students is limited and should be enhanced. Finally, personal contact between the resource persons and the students before the distant learning course commences helps the learning process.

Project "Periodontology Virtual Class" was organized by European Dental Students Association (EDSA) and was based on the following principles:
	until August 1998 students were able to join the group, and the rest who were late became observers.
	Students got interactive CD with lessons compiled from a dream team of top class Periodontology professors.
	Three groups of students were created for this project.
	Through e-mail people from each group were arranging meeting on Internet.
	In exact time all student from the group with their mentor were online through ICQ or mIRC.
	Online presentation of Perio case started (with a help of interactive CD) , and afterwards students were discussing the case .Their mentor was answering all their questions.
This project was lead by top class Periodontology professors:
	Professor Rolf Attstrom- head of Perio clinic in University Lund, Malmo, Sweden
	Professor Rutger Persson- Perio specialist- director of Perio center in University of Washington, U.S.A.
	Professor Niklaus Lang - head of Perio department and fixed prosthetics department in University of Bern in Swisseland. Professor Joerg Meyle - periodontologist in University Giessen, Germany
	Professor Mariano Sanz - Periodontologist in University Madrid, Spain.
Three groups of students were coming from different European countries: Hungary, Romania, Yugoslavia, Sweden, Holland, Greece, Bulgaria, Poland, Portugal, Malta, Turkey and Denmark.