title: Effect of ultraviolet photofunctionalisation on the cell attractiveness of zirconia implant materials.
abstract: Ultraviolet (UV) light treatment of implant surfaces has been demonstrated to enhance their bioactivity significantly. This study examined the effect of UV treatment of different zirconia surfaces on the response of primary human alveolar bone-derived osteoblasts (PhABO). Disks of two zirconia-based materials with two different surface topographies (smooth, roughened) were exposed to UV light. Qualitative and quantitative assessment of PhABO on zirconia surfaces, by means of immunofluorescence, scanning electron microscopy and DNA quantification at 4 and 24 h revealed a higher number of initially attached osteoblasts on UV-treated surfaces. Cell area and perimeter were significantly larger on all UV-treated surfaces (p<0.05). The proliferation activity was significantly higher on both roughened UV-treated surfaces than on untreated samples at day 3 of culture (p<0.05). The expression levels of collagen I, osteopontin and osteocalcin at day 14 and alkaline phosphatase activity at day 7 and 14 of culture period were similar among UV-treated and untreated surfaces. Alizarin-Red-Staining at day 21 demonstrated significantly more mineralised nodules on UV-treated samples than on untreated samples. Contact angle measurements and X-ray photoelectron spectroscopy showed that UV light transformed zirconia surfaces from hydrophobic to (super-) hydrophilic (p<0.05) and significantly reduced the atomic percentage of surface carbon. The results showed that UV light pre-treatment of zirconia surfaces changes their physicochemical properties and improves their attractiveness against PhABO, primarily demonstrated by an augmented cell attachment and spreading. This may result in faster healing and better bone-to-implant contact of zirconia implants in vivo following such a pre-treatment.
authors.affiliation: Department of Prosthodontics, School of Dentistry, Albert-Ludwigs University of Freiburg, Hugstetter Strasse 55, Freiburg 79106, Germany.ttuna@ukaachen.de.
authors.forename: T
authors.initials: T
authors.lastname: Tuna
authors.forename: M
authors.initials: M
authors.lastname: Wein
authors.forename: B
authors.initials: B
authors.lastname: Altmann
authors.forename: T
authors.initials: T
authors.lastname: Steinberg
authors.forename: J
authors.initials: J
authors.lastname: Fischer
authors.forename: W
authors.initials: W
authors.lastname: Att
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000539:Alveolar Process / Q000166:cytology; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D055598:Chemical Phenomena / Q000528:radiation effects; D024042:Collagen Type I / Q000235:genetics; D000090602:Collagen Type I, alpha 1 Chain; D015921:Dental Implants; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions / Q000528:radiation effects; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D015675:Osteocalcin / Q000235:genetics; D053495:Osteopontin / Q000235:genetics; D056951:Photoelectron Spectroscopy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013499:Surface Properties / Q000528:radiation effects; D013997:Time Factors; D014466:Ultraviolet Rays; D015040:Zirconium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D015921:Dental Implants; D015675:Osteocalcin; D053495:Osteopontin; D015040:Zirconium; D000469:Alkaline Phosphatase; C028541:zirconium oxide