title: Tissue integration of a new titanium-zirconium dental implant: a comparative histologic and radiographic study in the canine.
abstract: BACKGROUND
  This study evaluates a newly developed titanium-zirconium implant (TiZr), comparing it to a commercially available pure titanium (Ti) implant subjected to the same surface treatment.
  
  
  METHODS
  In nine dogs, 12 implants (six TiZr and six Ti) were randomly placed in the mandible with the implant shoulder at the bone crest and subjected to submerged healing. Standardized radiographs were taken after implantation, and at the sacrifice of 2 weeks (three dogs), 4 weeks (three dogs), and 8 weeks (three dogs). Histologic and histomorphometric measurements were performed on non-decalcified histologic sections. The main outcome measures included the first bone-implant contact (fBIC) and BIC over time. For statistical analysis, Wilcoxon signed-rank test and mixed model regressions were applied.
  
  
  RESULTS
  From baseline to 8 weeks, a mean bone loss of 0.09 ± 0.33 mm for TiZr and a gain of 0.02 ± 0.33 mm for Ti were calculated radiographically. The number of implants with the fBIC coronal to the reference point (implant shoulder) gradually increased over time, reaching 39% of all TiZr implants and 50% of all Ti implants at 8 weeks. The mean fBIC values for Ti and TiZr were 0.29 ± 0.42 mm and 0.26 ± 0.32 mm (2 weeks), -0.01 ± 0.20 mm and 0.10 ± 0.28 mm (4 weeks), and -0.06 ± 0.22 mm and 0.08 ± 0.30 mm (8 weeks), respectively. The mean BIC values peaked at 86.9% ± 6.8% (8 weeks) for TiZr and at 83.4% ± 5.9% (4 weeks) for Ti. No statistically significant differences were observed at any time point.
  
  
  CONCLUSIONS
  TiZr and Ti bone level implants with chemically-modified, sandblasted, and acid-etched surfaces performed similarly in regards to osseointegration in this unloaded canine study.
authors.affiliation: Clinic for Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland. daniel.thoma@zzmk.uzh.ch
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Thoma
authors.forename: Archie A
authors.initials: AA
authors.lastname: Jones
authors.forename: Michel
authors.initials: M
authors.lastname: Dard
authors.forename: Leticia
authors.initials: L
authors.lastname: Grize
authors.forename: Marcel
authors.initials: M
authors.lastname: Obrecht
authors.forename: David L
authors.initials: DL
authors.lastname: Cochran
mesh_terms: D000818:Animals; D003722:Dental Alloys; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D007091:Image Processing, Computer-Assisted; D008297:Male; D016348:Osseointegration; D011897:Random Allocation; D013499:Surface Properties; D014025:Titanium; D015040:Zirconium
chemical_list: D003722:Dental Alloys; D015921:Dental Implants; D015040:Zirconium; D014025:Titanium