[1] Univ Coimbra, Fac Med, Inst Periodontol, Dent Dept, P-3000075 Coimbra, Portugal
[2] Univ Coimbra, Fac Med, Inst Oral Med & Surg, Dent Dept, P-3000075 Coimbra, Portugal
[3] Univ Ctr Dent Med Basel, Clin Periodontol Endodontol & Cariol, CH-4058 Basel, Switzerland
[4] Univ Coimbra, Fac Med, Inst Operat Dent, Dent Dept, P-3000075 Coimbra, Portugal
[5] Univ Coimbra, Fac Med, Lab Biostat & Med Informat IBILI, P-3000548 Coimbra, Portugal