1. Khalid Almas:
Department of Preventive Dental Sciences, King Saud University College of Dentistry, P.O.Box-60169, Riyadh.11545, Saudi Arabia
2. Emad Al-Shwaimi:
King Saud University College of Dentistry, Riyadh
3. Hamed Al-Shwaimi:
King Saud University College of Dentistry, Riyadh
4. Nils Skaug:
Department of Microbiology, Faculty of Odontology, University of Bergen, Norway