1. Department of Paediatric Dentistry, Faculty of Dentistry, Karadeniz Technical University, Trabzon, Turkey;
2. Department of Paediatric and Preventive Dentistry, Faculty of Dental Medicine, St Cyril and St Methodius University, Skopje, Macedonia;
3. Bluefield Centre for Biomaterials, London, United Kingdom;
4. Dental Physical Sciences, Institute of Dentistry, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom