Stefano Pagano1, Guido Lombardo2, Silvia Caponi3, Egidia Costanzi4, Alessandro Di Michele5, Stefano Bruscoli6, Iva Xhimitiku7, Maddalena Coniglio8, Chiara Valenti9, Maurizio Mattarelli10, Gianluca Rossi11, Stefano Cianetti12, Lorella Marinucci13. 1. Department of Biomedical and Surgical Sciences, Odontostomatological University Centre: Chair Prof. Stefano Cianetti, University of Perugia, Perugia, Italy. Electronic address: stefano.pagano@unipg.it. 2. Department of Biomedical and Surgical Sciences, Odontostomatological University Centre: Chair Prof. Stefano Cianetti, University of Perugia, Perugia, Italy. Electronic address: guido.lombardo@unipg.it. 3. Istituto Officina dei Materiali del CNR (CNR-IOM), Perugia Unit, Department of Physics and Geology, University of Perugia, Perugia, Italy. Electronic address: silvia.caponi@cnr.it. 4. Department of Experimental Medicine, Section of Biosciences and Medical Embryology, University of Perugia, Perugia, Italy. Electronic address: egidia.costanzi@unipg.it. 5. Department of Physics and Geology, University of Perugia, Perugia, Italy. Electronic address: alessandro.dimichele@collaboratori.unipg.it. 6. Department of Medicine, Section of Pharmacology, University of Perugia, Perugia, Italy. Electronic address: stefano.bruscoli@unipg.it. 7. Department of Engineering, University of Perugia, Perugia, Italy. Electronic address: ivaxhimyiku@gmail.com. 8. Department of Biomedical and Surgical Sciences, Odontostomatological University Centre: Chair Prof. Stefano Cianetti, University of Perugia, Perugia, Italy. Electronic address: conigliomaddalena@gmail.com. 9. Department of Biomedical and Surgical Sciences, Odontostomatological University Centre: Chair Prof. Stefano Cianetti, University of Perugia, Perugia, Italy. Electronic address: chiara.valenti@studenti.unipg.it. 10. Department of Physics and Geology, University of Perugia, Perugia, Italy. Electronic address: maurizio.mattarelli@unipg.it. 11. Department of Engineering, University of Perugia, Perugia, Italy. Electronic address: gianluca.rossi@unipg.it. 12. Department of Biomedical and Surgical Sciences, Odontostomatological University Centre: Chair Prof. Stefano Cianetti, University of Perugia, Perugia, Italy. Electronic address: stefano.cianetti@unipg.it. 13. Department of Experimental Medicine, Section of Biosciences and Medical Embryology, University of Perugia, Perugia, Italy. Electronic address: lorella.marinucci@unipg.it.
Abstract
OBJECTIVE: To compare the mechanical and biological features of a polymethylmethacrylate (PMMA) disc for CAD/CAM prostheses (test samples, TG) with a traditional resin (control samples, CG). METHODS: Mechanical analysis was performed using Dynamic Mechanical Analysis (DMA) and Brillouin's micro-spectroscopy. Human keratinocyte morphology and adhesion were analyzed by scanning electronic microscopy (SEM), cytotoxicity by the MTT assay, apoptosis by flow cytometry and p53, p21 and bcl2 gene expression by real time PCR. RESULTS: TG exhibited a higher elastic modulus than CG (range 5100-5500 ± 114.3 MPa vs 3000-3300 ± 99.97 MPa). The Brillouin frequency was found at ωB= (15.50 ± 0.05) GHz for TG and at ωB_1 = (15.50 ± 0.05) GHz and ωB_2 = (15.0 ± 0.1) GHz for CG where two peaks were always present independently of the sample point. SEM analysis revealed that keratinocytes on TG disks appeared to be flattened with lamellipodia. Keratinocytes on CG disks rose above the substrate with cytoplasmatic filaments. MTT viability data at 3 h and 24 h showed TG was significantly less cytotoxic than CG (p < 0.001). No significant differences emerged in apoptosis on CG and TG. Real-time PCR showed p53 expression increased after 3 h by about 9-fold in keratinocytes on TG (p < 0.001) and about 5-fold in those on CG (p < 0.001). High p53 expression persisted after 24 h on both disks. No significant variations were observed in p21 and bcl2 expression at any time-point. SIGNIFICANCE: PMMA resins, as used in CAD/CAM technology, displayed suitable biocompatible and mechanical properties for removable prostheses.
OBJECTIVE: To compare the mechanical and biological features of a polymethylmethacrylate (PMMA) disc for CAD/CAM prostheses (test samples, TG) with a traditional resin (control samples, CG). METHODS: Mechanical analysis was performed using Dynamic Mechanical Analysis (DMA) and Brillouin's micro-spectroscopy. Human keratinocyte morphology and adhesion were analyzed by scanning electronic microscopy (SEM), cytotoxicity by the MTT assay, apoptosis by flow cytometry and p53, p21 and bcl2 gene expression by real time PCR. RESULTS:TG exhibited a higher elastic modulus than CG (range 5100-5500 ± 114.3 MPa vs 3000-3300 ± 99.97 MPa). The Brillouin frequency was found at ωB= (15.50 ± 0.05) GHz for TG and at ωB_1 = (15.50 ± 0.05) GHz and ωB_2 = (15.0 ± 0.1) GHz for CG where two peaks were always present independently of the sample point. SEM analysis revealed that keratinocytes on TG disks appeared to be flattened with lamellipodia. Keratinocytes on CG disks rose above the substrate with cytoplasmatic filaments. MTT viability data at 3 h and 24 h showed TG was significantly less cytotoxic than CG (p < 0.001). No significant differences emerged in apoptosis on CG and TG. Real-time PCR showed p53 expression increased after 3 h by about 9-fold in keratinocytes on TG (p < 0.001) and about 5-fold in those on CG (p < 0.001). High p53 expression persisted after 24 h on both disks. No significant variations were observed in p21 and bcl2 expression at any time-point. SIGNIFICANCE: PMMA resins, as used in CAD/CAM technology, displayed suitable biocompatible and mechanical properties for removable prostheses.