Dr. De Gregorio received his dental degree from the European University of Madrid in 2006. In 2008, he completed the Endodontic Program at the European University of Madrid with Honors and received the AEDE Best Research of a Graduate Student Award. He served from 2009 to 2013, on faculty at the school while maintaining a private practice limited to endodontics. He was in charge of bibliographic reviews of graduate students and serves as Clinical Assistant Professor of the Graduate Program. He received the title of Active Member of the Spanish Association of Endodontics in 2011. As a faculty member, he is active in research, teaching, and lectures nationally. 

He has published 13 articles in peer-reviewed journals these years after finishing his Graduate Program in Endodontics, most of them about root canal disinfection and more specifically fluid dynamics and apical negative pressure. He became Assistant Professor of the Department of Endodontics at the University of Washington in 2013 where served as a clinical assistant professor of the department of endodontics and as an endodontist at the Center for Pediatric Dentistry. His education and experience have made possible several invitations to domestic and international endodontic meetings. Actually, he serves as a Sub-Director of the Graduate Programme in Advanced Endodontics at Universidad Rey Juan Carlos (Madrid-Spain) as well as performs endodontic treatments in his private practice.