title: Response of osteoblast-like SAOS-2 cells to zirconia ceramics with different surface topographies.
abstract: OBJECTIVE
  Zirconia is a suitable biomaterial for use in medicine (stomatology, orthopaedics) due to its good biocompatibility and outstanding mechanical properties. This study compares the effect of (i) zirconia to the widely used titanium and (ii) zirconia with two different surface topographies (sandblasted and sandblasted/etched) on the adhesion, proliferation and differentiation of SAOS-2 osteoblasts.
  
  
  METHODS
  SAOS-2 cells were cultured on either sandblasted or sandblasted/etched zirconia and compared with sandblasted/etched titanium. 2 and 24 h after plating, cell morphology was investigated by scanning electron microscope (SEM) and fluorescence imaging. At 24 and 48 h, cell number-relevant parameters were determined. Alkaline phosphatase (ALP) activity and mineral accumulation were measured at days 8, 11, 15 and day 22 of culture, respectively.
  
  
  RESULTS
  SEM and fluorescence images revealed a faster spreading as well as higher number of adherent cells after 24 h incubation on zirconia compared with titanium. Also, the cellular metabolic activity after 24 h and the proliferation rate after 48 h is higher with zirconia compared with titanium. Zirconia had a more pronounced effect compared with titanium on the differentiation of SAOS-2 cells: ALP activity, an early differentiation marker increased earlier and mineralization, a late differentiation marker was increased. Only minor differences were found between zirconia with two different surface topographies; etched zirconia promoted slightly greater the differentiation of SAOS-2 cells.
  
  
  CONCLUSIONS
  These data indicate that zirconia mediates a pronounced stronger effect on the adhesion, proliferation and differentiation compared with titanium; and that topographical differences of zirconia have minor effects on osteoblast biology.
authors.affiliation: Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, University of Technology, Dresden, Germany. ute.hempel@tu-dresden.de
authors.forename: Ute
authors.initials: U
authors.lastname: Hempel
authors.forename: Thomas
authors.initials: T
authors.lastname: Hefti
authors.forename: Marie
authors.initials: M
authors.lastname: Kalbacova
authors.forename: Cornelia
authors.initials: C
authors.lastname: Wolf-Brandstetter
authors.forename: Peter
authors.initials: P
authors.lastname: Dieter
authors.forename: Falko
authors.initials: F
authors.lastname: Schlottig
mesh_terms: D000134:Acid Etching, Dental; D020906:Air Abrasion, Dental; D000469:Alkaline Phosphatase / Q000378:metabolism; D000704:Analysis of Variance; D001672:Biocompatible Materials / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002516:Ceramics / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology; D015040:Zirconium / Q000494:pharmacology*
chemical_list: D001672:Biocompatible Materials; D015040:Zirconium; D014025:Titanium; D000469:Alkaline Phosphatase; C028541:zirconium oxide