Dr. Sugai received his PhD degree from Osaka University, School of Dentistry.

From 1989 to 1994, he was a surgical clinical fellow and a visiting associate professor of Oral-facial Implant Center at UCLA. In 1998, he established UC Medical Corporation and maintains two dental implant centers in Tokyo. Currently, he is a clinical professor of Oral Implantology at Tokyo Medical and Dental University. Dr. Sugai has written numerous articles related to implant dentistry, focusing on sinus lift and bone grafting. He offers many lectures internationally and nationally in scientific meetings. He is a director of Japanese Maxillofacial Implant society, a director of UCLA Implant Association Japan, director of Japan Society for Dental Anti-Aging, a councilor of Japanese Academy of Maxillofacial Prosthetics, a program committee of International Society of Maxillofacial Rehabilitation, and a member of Academy of Osseointegration.