title: Surface properties of titanium and zirconia dental implant materials and their effect on bacterial adhesion.
abstract: OBJECTIVE
  Zirconia ceramic material has been widely used in implant dentistry. In this in vitro study the physiochemical properties of titanium and zirconia materials were investigated and the affinity of different bacteria to different materials was compared.
  
  
  METHODS
  Disc samples with different surface states were used: polished partially stabilized zirconia (PZ), titanium blasted with zirconia (TBZ), titanium blasted with zirconia then acid etched (TBZA), and polished titanium (PT) as a control. Surface topography was examined using scanning electron microscopy and profilometry. Contact angle, surface free energy (SFE), surface microhardness and chemical composition were determined. Disc samples were separately incubated with Streptococcus mitis and Prevotella nigrescens, either with or without pre-coating with human saliva, for 6h and the surface area covered by bacteria was calculated from fluorescence microscope images.
  
  
  RESULTS
  PZ and TBZ exhibited lower surface free energy and lesser surface wettability than PT. Also, PZ and TBZ surfaces showed lower percentage of bacterial adhesion compared with control PT surface.
  
  
  CONCLUSIONS
  The zirconia material and titanium blasted with zirconia surface (TBZ surface) showed superior effect to titanium material in reducing the adhesion of the experimented bacteria especially after coating with saliva pellicle. Modifying titanium with zirconia lead to have the same surface properties of pure zirconia material in reducing bacterial adhesion. SFE appears to be the most important factors that determine initial bacterial adhesion to smooth surface.
authors.affiliation: School of Oral & Dental Sciences, Bristol Dental Hospital & School, UK. drafya_diab@yahoo.com
authors.forename: Afya Sahib Diab
authors.initials: AS
authors.lastname: Al-Radha
authors.forename: David
authors.initials: D
authors.lastname: Dymock
authors.forename: Charles
authors.initials: C
authors.lastname: Younes
authors.forename: Dominic
authors.initials: D
authors.lastname: O'Sullivan
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D001422:Bacterial Adhesion / Q000502:physiology*; D055598:Chemical Phenomena; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D044622:Dental Pellicle / Q000502:physiology; D003775:Dental Polishing / Q000295:instrumentation / Q000379:methods; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D056951:Photoelectron Spectroscopy; D045242:Prevotella nigrescens / Q000502:physiology; D034361:Streptococcus mitis / Q000502:physiology; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D017155:Wettability; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide