title: Osteoblastic behavior to zirconium coating on Ti-6Al-4V alloy.
abstract: OBJECTIVE
  The purpose of this study was to assess the surface characteristics and the biocompatibility of zirconium (Zr) coating on Ti-6Al-4V alloy surface by radio frequency (RF) magnetron sputtering method.
  
  
  METHODS
  The zirconium films were developed on Ti-6Al-4V discs using RF magnetron sputtering method. Surface profile, surface composition, surface roughness and surface energy were evaluated. Electrochemical test was performed to evaluate the corrosion behavior. Cell proliferation, alkaline phosphatase (ALP) activity and gene expression of mineralized matrix markers were measured.
  
  
  RESULTS
  SEM and EDS analysis showed that zirconium deposition was performed successfully on Ti-6Al-4V alloy substrate. Ti-6Al-4V group and Zr-coating group showed no significant difference in surface roughness (P>.05). Surface energy was significantly higher in Zr-coating group than in Ti-6Al-4V group (P<.05). No difference in cell morphology was observed between Ti-6Al-4V group and Zr-coating group. Cell proliferation was higher in Zr-coating group than Ti-6Al-4V group at 1, 3 and 5 days (P<.05). Zr-coating group showed higher ALP activity level than Ti-6Al-4V group (P<.05). The mRNA expressions of bone sialoprotein (BSP) and osteocalcin (OCN) on Zr-coating group increased approximately 1.2-fold and 2.1-fold respectively, compared to that of Ti-6Al-4V group.
  
  
  CONCLUSIONS
  These results suggest that zirconium coating on Ti-6Al-4V alloy could enhance the early osteoblast responses. This property could make non-toxic metal coatings on Ti-6Al-4V alloy suitable for orthopedic and dental implants.
authors.affiliation: School of Dentistry, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Bo-Ah
authors.initials: BA
authors.lastname: Lee
authors.affiliation: School of Dentistry, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Hae-Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Stomatology, Affiliated Hospital of Yanbian University, Yanji, Jilin, China.
authors.forename: Yun-Ze
authors.initials: YZ
authors.lastname: Xuan
authors.affiliation: School of Dentistry, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Yeong-Joon
authors.initials: YJ
authors.lastname: Park
authors.affiliation: School of Dentistry, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Chung
authors.affiliation: School of Dentistry, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Kim
keywords: Biocompatible materials; Cell proliferation; Surface properties; Surface-coated materials; Titanium; Zirconium