[1] Queens Univ Belfast, Div Restorat Dent Periodont, Sch Clin Dent, Dept Med, Belfast BT12 6BP, Antrim, North Ireland
[2] Univ Manchester, Turner Dent Sch, Manchester M15 6FH, Lancs, England
[3] Queens Univ Belfast, Sch Clin Dent, Belfast BT12 6BP, Antrim, North Ireland
[4] Manchester Royal Infirm, Cent Manchester Healthcare Trust, Renal Transplant Unit, Manchester M13 9WL, Lancs, England