1. Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy.
2. Industrial Engineering, University of Catania, Catania, Italy.
3. Department of Endodontics, La Sapienza University, Rome, Italy.
4. MATIS IMM-CNR and Department of Physics, University of Catania, Catania, Italy.
5. Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea.