[1] Univ Sharjah, Coll Dent Med, Dept Prevent & Restorat Dent, Sharjah, U Arab Emirates
[2] Hamad Med Corp, Hamad Dent Ctr, Doha, Qatar
[3] Univ Hosp Munster, Fac Dent, Dept Periodontol & Operat Dent, Munster, Germany
[4] Int Med Univ, Sch Dent, Kuala Lumpur, Malaysia
[5] Cardiff Univ, Coll Biomed & Life Sci, Sch Dent, Cardiff, Wales