Small-diameter titanium Grade IV and titanium-zirconium implants in edentulous mandibles: three-year results from a double-blind, randomized controlled trial

Clin Oral Implants Res. 2015 Jul;26(7):831-40. doi: 10.1111/clr.12367. Epub 2014 Apr 9.


Objective: The aim of this study was to compare crestal bone-level changes, soft tissue parameters and implant success and survival between small-diameter implants made of titanium/zirconium (TiZr) alloy or of Grade IV titanium (Ti) in edentulous mandibles restored with removable overdentures.

Materials and methods: This was a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann bone-level implants (diameter 3.3 mm), one of Ti Grade IV (control) and one of TiZr (test), in the interforaminal region. Implants were loaded after 6-8 weeks and removable Locator-retained overdentures were placed within 2 weeks of loading. Modified plaque and sulcus bleeding indices, radiographic bone level, and implant survival and success were evaluated up to 36 months.

Results: Of 91 treated patients, 75 completed the three-year follow-up. Three implants were lost (two control and one test implant). The survival rates were 98.7% and 97.3%, and the mean marginal bone level change was -0.78 ± 0.75 and -0.60 ± 0.71 mm for TiZr and Ti Grade IV implants. Most patients had a plaque score of 0 or 1 (54% for test and 51.7% for control), and a sulcus bleeding score of 0 (46.1% for test and 44.9% for control). No significant differences were found between the two implant types for bone-level change, soft tissue parameters, survival and success.

Conclusions: After 36 months, similar outcomes were found between Ti Grade IV and TiZr implants. The results confirm that the results seen at 12 months continue over time.

Keywords: Roxolid; SLActive surface; Titanium/zirconium; edentulous.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Dental Alloys
  • Dental Implantation, Endosseous / methods*
  • Dental Implants*
  • Dental Prosthesis Design
  • Denture, Overlay
  • Double-Blind Method
  • Female
  • Humans
  • Jaw, Edentulous / rehabilitation
  • Male
  • Mandible / surgery*
  • Titanium
  • Treatment Outcome
  • Zirconium


  • Dental Alloys
  • Dental Implants
  • Zirconium
  • Titanium