title: Surface micro-structuring of zirconia dental implants.
abstract: OBJECTIVE
  Sandblasting with subsequent acid etching is a potential procedure to generate microstructured surfaces on zirconia implants. The aim of the study was to systematically analyze the effect of these process steps on surface morphology and mechanical strength of the implants.
  
  
  METHODS
  Zirconia implant blanks (ceramic.implant, VITA) were sandblasted (105-μm alumina, 6 bar), subsequently HF-etched, and finally heat-treated at 1250°C. Surface topographies were documented by SEM. Surface roughness Ra (n = 4), monoclinic volume fraction in the surface layer (n = 1), and static fracture load (n = 4) were measured.
  
  
  RESULTS
  Surface roughness Ra reached a maximum of 1.2 μm after 4× sandblasting. Scratches and sharp edges dominated the surface aspect. Fracture load increased with the number of sandblasting cycles with a gain of 30% after 20 cycles. HF etching did not change the Ra values, but sharp edges were rounded and small pits created. A minor decrease in fracture load with increasing etching time was observed. Heat treatment of 1 h reduced the fracture load by 1/3. Longer heat treatment had no further effect. The roughness Ra was not modified by heat treatment. Fracture load was strongly correlated with the monoclinic fraction except for the results obtained directly after acid etching, where a constant monoclinic fraction was observed.
  
  
  CONCLUSIONS
  Sandblasting with 105-μm alumina followed by 1 h HF etching at room temperature and 1 h heat treatment at 1250°C is a reliable and tolerant process to create a surface roughness of about Ra  = 1.2 μm on zirconia implants.
authors: Institute for Materials Science and Engineering, University Hospital of Dental Medicine, University of Basel, Basel, Switzerland.|Division of Prosthodontics, Department of Dental, Oral and Maxillofacial Surgery, University Medical Center, University of Freiburg, Freiburg, Germany.|VITA Zahnfabrik, Bad Säckingen, Germany.
authors: J
authors: J
authors: Fischer
authors: Division of Prosthodontics, Department of Dental, Oral and Maxillofacial Surgery, University Medical Center, University of Freiburg, Freiburg, Germany.
authors: A
authors: A
authors: Schott
authors: VITA Zahnfabrik, Bad Säckingen, Germany.
authors: S
authors: S
authors: Märtin
mesh_terms: D000134:Acid Etching, Dental; D045662:Dental Etching / Q000379:methods*; D015921:Dental Implants; D019232:Dental Restoration Failure; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013314:Stress, Mechanical; D013499:Surface Properties; D015040:Zirconium
chemical_list: D015921:Dental Implants; D015040:Zirconium; C028541:zirconium oxide
keywords: fracture load; microstructure; monoclinic phase; roughness; zirconia implants