title: Dental zirconia implants up to three years in function: a retrospective clinical study and evaluation of prosthetic restorations and failures.
abstract: OBJECTIVE
  The clinical evaluation of one-piece zirconia dental implants with different diameters to determine survival rate and type of implant failure.
  
  
  METHODS
  Information concerning implant surgery (number, diameter, length, and position of inserted implants; patient age, sex, risk factors, and bone quality) was extracted from the clinical records. All treated patients were then recalled for a follow-up examination to check the current clinical parameters concerning soft tissue, implants, and prosthetic reconstructions.
  
  
  RESULTS
  A total of 79 patients received 170 implants (diameter-reduced 3.25 mm: n = 59; diameter 4.0 mm: n = 82; diameter 5.0 mm: n = 29). The clinical examination showed no signs of gingival inflammation. Prosthetic information was available for 119 implants restored with single crowns (87 implants), fixed partial dentures (25 implants), and removable hybrid dentures (7 implants). Overall, 30 implants were lost due to lack of osseointegration (n = 17) or fracture (n = 13). The diameter-reduced implants showed the lowest survival rate (59.5%) compared to the implants with a diameter of 4.0 mm (90.6%) and 5.0 mm (73.9%). The survival rate for diameters of 3.25 mm was significantly lower than that for diameters of 4.0 mm. The estimated cumulative survival rate up to 3 years demonstrated a survival probability of 82.4% for all types of implant diameters and failure.
  
  
  CONCLUSIONS
  Based on these results, diameter-reduced zirconia dental implants cannot be recommended for clinical use. The overall survival rate of 82.4% is not acceptable in comparison to the well-established survival rate of titanium implants.
authors.affiliation: Clinical Department of Restorative and Prosthetic Dentistry, Innsbruck Medical University, Innsbruck, Austria. m.gahlert@knihagahlert.de
authors.forename: Michael
authors.initials: M
authors.lastname: Gahlert
authors.forename: Doris
authors.initials: D
authors.lastname: Burtscher
authors.forename: George
authors.initials: G
authors.lastname: Pfundstein
authors.forename: Ingrid
authors.initials: I
authors.lastname: Grunert
authors.forename: Heinz
authors.initials: H
authors.lastname: Kniha
authors.forename: Stefan
authors.initials: S
authors.lastname: Roehling
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003442:Crowns; D015921:Dental Implants / Q000706:statistics & numerical data*; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported / Q000706:statistics & numerical data*; D019232:Dental Restoration Failure / Q000706:statistics & numerical data*; D003830:Denture, Partial, Fixed; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult; D015040:Zirconium
chemical_list: D015921:Dental Implants; D015040:Zirconium; C028541:zirconium oxide