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[2] PUBL DENT SERV KISTA, DEPT PERIODONTOL, KISTA, SWEDEN
[3] PUBL DENT SERV BERGSHAMRA, DEPT PERIODONTOL, BERGSHAMRA, SWEDEN
[4] KAROLINSKA INST, DEPT HISTOL, S-10401 STOCKHOLM 60, SWEDEN
[5] KAROLINSKA INST, SCH DENT, DEPT ORAL PATHOL, S-10401 STOCKHOLM 60, SWEDEN