1. Division of Postgraduate Prosthodontics; Tufts University School of Dental Medicine; Boston MA USA
2. Department of Prosthodontics; School of Dentistry; National and Kapodistrian University of Athens; Athens Greece
3. Division of Regenerative and Implant Sciences; Harvard School of Dental Medicine; Boston MA USA
4. Department of Dentistry; Chi Mei Medical Center; Tainan Taiwan
5. Layerwise; Leuven Belgium
6. Prosthetics Section; Department of Oral health Sciences; Catholic University of Leuven; Leuven Belgium