1. Clinical Research Center for Periodontal Diseases, School of Dentistry, Medical College of Virginia, Virginia Commonwealth University, Box 980566, Richmond, Virginia 23298-0566
2. Clinical Research Center for Periodontal Diseases, School of Dentistry, Medical College of Virginia, Virginia Commonwealth University, Box 980566, Richmond, Virginia 23298-0566, Department of Periodontology, Faculty of Dentistry, Tokyo Medical and Dental University, 5-45, Yushima 1-chome, Bunkyo-ku, Tokyo 113, Japa
3. Clinical Research Center for Periodontal Diseases, School of Dentistry, Medical College of Virginia, Virginia Commonwealth University, Box 980566, Richmond, Virginia 23298-0566, Baxter Biotech, 1720 Flower Ave, Duarte, California 91010