title: Influence of surface treatment of yttrium-stabilized tetragonal zirconium oxides and cement type on crown retention after artificial aging.
abstract: BACKGROUND
  Information about the influence of zirconia crown surface treatment and cement type on the retention of zirconia crowns is limited. It is unclear whether zirconia crowns require surface treatment to enhance their retention.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to evaluate the effect of surface treatment on the retention of zirconia crowns cemented with 3 different adhesive resin cements after artificial aging.
  
  
  METHODS
  Ninety extracted human molars were prepared for ceramic crowns (approximately 20-degree taper, approximately 4-mm axial length) and were divided into 3 groups (n=30). Computer-aided design and computer-aided manufacturing zirconia copings were fabricated. Three surface treatments were applied to the intaglio surface of the copings. The control group received no treatment, the second group was airborne-particle abraded with 50 μm Al2O3, and the third group was treated with 30 μm silica-modified Al2O3, The copings were luted with a self-etch (RelyX Unicem 2), a total-etch (Duo-Link), or a self-etch primer (Panavia F 2.0) adhesive cement. They were stored for 24 hours at 37°C before being artificially aged with 5000 (5°C-55°C) thermal cycles and 100,000 cycles of 70 N dynamic loading. Retention was measured on a universal testing machine under tension, with a crosshead speed of 0.5 mm/min. Statistical analysis was performed with 1-way and 2-way ANOVA.
  
  
  RESULTS
  Mean retention values ranged from 0.72 to 3.7 MPa. Surface treatment increased crown retention, but the difference was not statistically significant (P>.05), except for the Duo-Link cement group (P<.05). Analysis of the adhesives revealed that the Duo-Link cement resulted in significantly lower crown retention (P<.05) than the other 2 cements.
  
  
  CONCLUSIONS
  For zirconia crowns, retention seems to be dependent on cement type rather than surface treatment.
authors: Resident, Department of Restorative Sciences, School of Dentistry University of Alabama at Birmingham, Birmingham, Ala.
authors: Mehdi
authors: M
authors: Karimipour-Saryazdi
authors: Assistant Professor, Department of Restorative Sciences, University at Buffalo School of Dental Medicine, Buffalo, NY. Electronic address: rsadidza@buffalo.edu.
authors: Ramtin
authors: R
authors: Sadid-Zadeh
authors: Associate Professor, Department of Restorative Sciences, School of Dentistry University of Alabama at Birmingham, Birmingham, Ala.
authors: Daniel
authors: D
authors: Givan
authors: Professor and Assistant Dean for Clinical Research, Department of Clinical and Community Sciences, School of Dentistry University of Alabama at Birmingham, Birmingham, Ala.
authors: John O
authors: JO
authors: Burgess
authors: Associate Professor, Department of Restorative Sciences, School of Dentistry University of Alabama at Birmingham, Birmingham, Ala.
authors: Lance C
authors: LC
authors: Ramp
authors: Professor and Chair, Department of Restorative Sciences, School of Dentistry University of Alabama at Birmingham, Birmingham, Ala.
authors: Perng-Ru
authors: PR
authors: Liu
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D017076:Computer-Aided Design; D003442:Crowns; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D019231:Tooth Preparation, Prosthodontic / Q000379:methods; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; C431350:Duo-Link; C438843:Panavia-Fluoro; C483701:Rely X Unicem; D019279:Resin Cements; C499362:yttria stabilized tetragonal zirconia; D015019:Yttrium; D012822:Silicon Dioxide; D015040:Zirconium; D000537:Aluminum Oxide