[1] Kristianstad Univ, Dept Oral Sci, SE-29188 Kristianstad, Sweden
[2] Univ Dublin Trinity Coll, Sch Dent Sci, Dublin 2, Ireland
[3] Blekinge Inst Technol, Karlskrona, Sweden
[4] Uppsala Kakkirurgiska Ctr, Uppsala, Sweden
[5] Hosp Halland, Dept Periodontol, Maxillofacial Unit, Halmstad, Sweden
[6] Univ Washington, Dept Periodont, Seattle, WA 98195 USA
[7] Univ Washington, Dept Oral Med, Seattle, WA 98195 USA
[8] Univ Bern, Dept Periodontol, Bern, Switzerland