Antibacterial TiO
2/Ag/polymer nanohybrid coatings of dental implants
Zsófia Tarnai1, Ágnes Györgyey1, László Janovák2, Szabolcs Tallósy2, Judit Kopniczky3, Krisztina Buzás1, István Pelsőczi-Kovács1, János Minárovits1, Zoltán Rakonczay1, Katalin Nagy4, Frédéric
Cuisinier5, Imre Dékány6, Kinga Turzó1
1Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, 6720 Szeged, Tisza L. 64. Hungary
2Department of Physical Chemistry and Material Sciences, Faculty of Science and Informatics, University of Szeged, 6720 Szeged, Aradi Vt. 1, Hungary,
3Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, 6720 Szeged, Aradi Vt. 1, Hungary
4Department of Oral Surgery, Faculty of Dentistry, University of Szeged, 6720 Szeged, Tisza L. 64. Hungary
5UFR Odontologie, Université Montpellier I, 34193 Montpellier, 545 Avenue prof. Viala, France
6Supramolecular and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, Department of Medical Chemistry, Faculty of Medicine, 6720 Szeged, Aradi Vt. 1, Hungary
Objectives: Dental implantology dealing with the rehabilitation of the damaged chewing apparatus due to loss of natural teeth is the most intensively developing field of prosthetic dentistry. The failure of a dental implant is mainly caused by the inflammatory processes affecting the soft and hard tissues, the peri-implant infections. Peri-implant diseases have been primarily linked to Gram-negative anaerobic microflora. The developed TiO2/Ag/polymer composite can serve as an antibacterial coating preventing peri-implant infections. Photocatalytic properties of the composite activated by UV light will act against typical colonizers of the oral cavityand for the detoxification of the titanium surfaces.
Destruction of the bacterial toxins is a key point to have a new osseointegration occurring around the implant.
Materials and methods:
Titanium discs (Grade CP4) 1.5 mm thick and 9 mm in diameter were acid-etched and sand-blasted (Denti® System Ltd. Hungary). The following coatings were developed preparing copolymer based nanohybrid layers: i) acrylate based copolymer film; ii) 60% TiO2/40% copolymer; iii) 60%
DSTiO2/40% copolymer; iv) 60% AgTiO2/40% copolymer; v) 60% AgDSTiO2/40% copolymer.
Dodecyl-sulphate (DS) gave the hydrophobic feature of the surface. The roughness (Ra) of the samples was determined with AFM (PSIA XE-100, South Korea) and the surfaces were visualized with SEM (Hitachi S4700, Japan). Total amount of protein of P. gingivalis was measured by a Micro BCA Protein Assay Kit (Pierce Biotechnology, USA). The number of E. coli colonies was measured by mechanical removing (vortex) of the biofilm from the surface.
Results:
AFM measurements gave 544 ± 47 nm (mean ± SEM) roughness (Ra) value for the control samples, 33 ± 10 nm for sample (i), 289 ± 44 nm for sample (ii), 293 ± 52 nm for sample (iii) 511 ± 56 nm for sample (iv), 183 ± 16 nm for sample (v). Aggregated particles on sample (iv) and (v) were visible by SEM. A significant decrease of the number of E. coli colonies on the AgDSTiO2/ copolymer coating (v) was observed by microbiological testing, compared to the control discs. The total protein of attached Porphiromonas gingivalis increased on the AgDSTiO2/copolymer layer.
Conclusion:
The roughness of the 60% AgTiO2/40% copolymer coating was similar to the control surface roughness. As shown by the E. coli experiments the hydrophobic (DS) coating containing Ag nanoparticles (v) may be an effective antibacterial material against typical colonizers of the oral cavity.
Acknowledgments:
Supported by the following projects: TÁMOP-4.2.2/B-10/1-2010-0012 - “Broadening the knowledge base and supporting the long term professional sustainability of the Research University Centre of Excellence at the University of Szeged by ensuring the rising generation of excellent scientists.”
supported by the European Union and co-funded by the European Social Fund.; TÁMOP-4.2.1/B- 09/1/KONV-2010-0005 – "Creating the Centre of Excellence at the University of Szeged” supported
by the European Union and co-financed by the European Regional Development Fund; Hungarian- French Intergovernmental S&T Cooperation Program, TéT_10-1-2011-0708; K. Turzó was supported by the János Bolyai Research Scholarship of the Hung. Acad. of Sciences.
