LOGIN
 
Share Page:
Back

Volume 24 , Issue 2
March/April 2009

Pages 267–274


The Influence of Extraction on the Stability of Implanted Titanium Microscrews: A Biomechanical and Histomorphometric Study

Leilei Zheng/Tian Tang/Feng Deng/Zhihe Zhao


PMID: 19492642

Purpose: The purpose of this study was to explore the influence of extraction on the stability of implanted titanium microscrews. Materials and Methods: Six male beagle dogs received 96 microscrews between the mesial and distal roots of the second, third, and fourth premolars and the first molar in both maxillae and mandibles. The third and fourth premolars were extracted from each dog. Test implants were placed near the extraction sites, and control implants were placed at a distance from the extraction sites. The bone remodeling process at the interface was studied through bio­mechanical pull-out testing, histomorphologic observation, and histomorphometric asssessment after different amounts of healing time (1, 3, or 8 weeks). Results: Two microscrews were loose in the test group at week 1. Near the extraction regions, both the peak pullout force at extraction (Fmax) and the bone-implant contact (BIC) of the microscrews were lower than that seen in the control group at week 1, but quickly surpassed the control groups at week 3. After 8 weeks of healing time, Fmax and BIC values between test and control groups exhibited no differences. The lowest BIC value was 10.12%, and the corresponding pull-out force was 100.23 N. At week 1, the inflammatory reaction at the bone-implant interface in the test groups was stronger than in the control groups. At week 3, many active osteoblasts gathered along the interface and a bone matrix excreted by osteoblasts around the microscrew were observed in the test group. Conclusions: A BIC of at least 10% provided resistance to orthodontic forces. For microscrews placed near extraction regions, the risk of loosening was highest in the first week following implant placement. The most active bone remodeling at the implant-bone interface occurred 3 weeks after implantation, especially for screws near extraction regions. Int J Oral Maxillofac Implants 2009;24:267–274


Full Text PDF File | Order Article

 

 
Get Adobe Reader
Adobe Acrobat Reader is required to view PDF files. This is a free program available from the Adobe web site.
Follow the download directions on the Adobe web site to get your copy of Adobe Acrobat Reader.

 

© 2014 Quintessence Publishing Co, Inc JOMI Home
Current Issue
Ahead of Print
Archive
Author Guidelines
About
Accepted Manuscripts
Submission Form
Submit
Reprints
Permission
Advertising
Quintessence Home
Terms of Use
Privacy Policy
About Us
Contact Us
Help