1. ASST Valle Olona, Dental Unit, 21052 Gallarate, Italy
2. Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20112 Milano, Italy
3. Department of Medicine and Surgery, School of Dentistry, University of Insubria, 21100 Varese, Italy
4. Department of Oral Medicine and Paediatric Dentistry, University of Brescia, 25121 Brescia, Italy
5. Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, 3012 Bern, Switzerland
6. Graduate School for Health Sciences, University of Bern, 3012 Bern, Switzerland
7. Department of Periodontology and Operative Dentistry, University Medical Center of the Jhoannes Gutenberg University Mainz, 55116 Mainz, Germany