title: In vitro performance of one- and two-piece zirconia implant systems for anterior application.
abstract: To investigate the long-term in vitro performance and fracture resistance of one-piece and bonded two-piece zirconia implant systems for anterior application.
  
  
  
  Two groups of bonded two-piece zirconia (ZZB), four groups of one-piece zirconia (Z), and two groups of two-piece titanium (TTS, reference) implant systems were restored with identical monolithic zirconia crowns (n=10/group). Eight specimens per group were mounted at an angle of 135° in the chewing simulator and subjected to thermal cycling (TC:18,000 cycles; 5°/55°) and mechanical loading (ML:3.6×10(6) cycles; 100N) simulating an anterior situation. Fracture resistance and maximum bending stress were determined for specimens that survived aging and for two references per group after 24h water storage. SEM pictures were used for failure analysis. Data were statistically analysed (one-way-ANOVA, post-hoc Bonferroni, Kaplan-Meier-Log-Rank, α=0.05).
  
  
  
  A one-piece zirconia and a two-piece titanium implant system survived TCML without failures. Both bonded two-piece zirconia implant systems and a one-piece zirconia implant system totally failed (fractures of abutment or implant). Failure numbers of the other systems varied between 1× (1 group) and 5× (2 groups). Significantly different survival rates were found (Log-Rank-test: p=0.000). Maximum fracture forces/bending stresses varied significantly (
  
  
  
  p=0.000) between 188.00±44.80N/381.02±80.15N/mm(2) and 508.67±107.00N/751.45±36.73N/mm(2). Mean fracture values after 24h water storage and TCML were not significantly different.
  
  
  
  Zirconia implant systems partly showed material defects or connection insufficiencies. Bonded two-piece systems had higher failure rates and lower fracture resistance than one-piece implants.
  
  
  
  Individual zirconia implant systems may be applied in anterior regions with limitations.
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Regensburg 93042, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Kammermeier
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Regensburg 93042, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Rosentritt
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Regensburg 93042, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Behr
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Regensburg 93042, Germany.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Schneider-Feyrer
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Regensburg 93042, Germany. Electronic address: verena.preis@ukr.de.
authors.forename: Verena
authors.initials: V
authors.lastname: Preis
mesh_terms: D000044:Dental Abutments; D059605:Dental Implant-Abutment Design; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D008422:Materials Testing; D013314:Stress, Mechanical; D014025:Titanium; D015040:Zirconium
chemical_list: D015040:Zirconium; D014025:Titanium
keywords: Chewing simulation; Fracture resistance; Implant; One-piece; Two-piece; Zirconia