1. Department of Medical Biotechnologies, University of Siena, Siena, Italy.
2. Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, University of Zurich, Zurich, Switzerland.
3. Department of Surgery and Translational Medicine, University of Florence, Florence, Italy.
4. University of Portsmouth Dental Academy, Portsmouth, United Kingdom.