1. Department of Oral Pathology, School of Dentistry, Karolinska Institutet, Box 4064, 141 04 Huddinge, Department of Periodontology, Skanstull
2. Department of Oral Pathology, School of Dentistry, Karolinska Institutet, Box 4064, 141 04 Huddinge
3. Department of Oral Pathology, School of Dentistry, Karolinska Institutet, Box 4064, 141 04 Huddinge, Department of Oral Surgery, Södersjukhuset
4. Primate Research Center, National Bacteriological Laboratory, Stockholm, Sweden