While teaching Dr.Green became active in Sports Dentistry and has continued both making mouthguards for and performing prevention and care of patients experiencing dental trauma from sports injuries and research in mouthgurds possibility in helping to prevent concussions. He is a member of the Academy FOr Sports Dentistry. He has done work for teams at West Virginia University, the University of Pittsburgh, Michigan University, University of Texas, U.C.L.A.,W&J College, and the Cleveland Clinic and also for professional athletes. At one time or another he has participated in being the team dentist or assisted in making mouthguards for the College teams and professional teams with players from the Pittsburgh Steelers, Cleveland Browns, Kansas City Chiefs, Minnesota Vikings, and San Diego Chargers. He has taught an extensive Sports Dentistry Program at the Pitt University Dental School in 1994.