A prospective, randomized-controlled clinical trial to evaluate bone preservation using implants with different geometry placed into extraction sockets in the maxilla

Clin Oral Implants Res. 2010 Jan;21(1):13-21. doi: 10.1111/j.1600-0501.2009.01824.x. Epub 2009 Nov 18.


Aim: The primary objective of this study was to determine the association between the size of the void established by using two different implant configurations and the amount of buccal/palatal bone loss that occurred during 16 weeks of healing following their installation into extraction sockets.

Material and methods: The clinical trial was designed as a prospective, randomized-controlled parallel-group multicenter study. Adults in need of one or more implants replacing teeth to be removed in the maxilla within the region 15-25 were recruited. Following tooth extraction, the site was randomly allocated to receive either a cylindrical (group A) or a tapered implant (group B). After implant installation, a series of measurements were made to determine the dimension of the ridge and the void between the implant and the extraction socket. These measurements were repeated at the re-entry procedure after 16 weeks.

Results: The study demonstrated that the removal of single teeth and the immediate placement of an implant resulted in marked alterations of the dimension of the buccal ridge (43% and 30%) and the horizontal (80-63%) as well as the vertical (69-65%) gap between the implant and the bone walls. Although the dimensional changes were not significantly different between the two-implant configurations, both the horizontal and the vertical gap changes were greater in group A than in group B.

Conclusions: Implant placement into extraction sockets will result in significant bone reduction of the alveolar ridge.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Alveolar Bone Loss / prevention & control*
  • Alveolar Bone Loss / surgery
  • Dental Implantation, Endosseous / methods*
  • Dental Implants, Single-Tooth*
  • Dental Prosthesis Design
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Tooth Extraction
  • Tooth Socket / surgery*
  • Treatment Outcome