IADR Abstract Archives

Insertion and removal torque of immediately-loaded stainless steel mini-screw implants

Objective: Stainless steel (SS) mini-screw implants (MSI) have been introduced as temporary anchorage devices for orthodontic space closure.  However, detailed characterization on the mechanical properties of SS-MSI is still lacking.  The purpose of this study was to compare their stability, insertion torque (IT) and, removal torque (RT), with traditional titanium alloy (TiA) MSIs under loaded and unloaded conditions.  

Method: Forty-eight SS (medical class 316 LVM) and 48 TiA (Ti6Al4V) MSIs (6mm long, 1.6mm diameter) were inserted into the tibias of 12 male 4-5 months old New Zealand white rabbits.  Four alternating implants were randomly allocated to each tibia.  Nickel titanium coil springs were used to apply 100g force to a random adjacent pair of implants in each tibia.  IT and primary stability were recorded at placement.  RT was measured and final stability was evaluated after euthanasia at 6 weeks of healing.  

Result: All implants remained stable.  SS had significantly (p=0.0048) higher insertion torque but there was no significant difference in RT.  Loading and implant locations were not associated with IT and RT.  

Conclusion: SS and TiA MSIs provided satisfactory stability when subjected to 100g of immediate orthodontic loading for 6 weeks in rabbit tibias.  While SS MSIs generated significantly higher (9%) IT than TiA MSIs, the difference may not be clinically significant.  Simialr RT was generated for both SS and TiA MSIs.

Division: IADR/AADR/CADR General Session
Meeting: 2013 IADR/AADR/CADR General Session (Seattle, Washington)
Location: Seattle, Washington
Year: 2013
Final Presentation ID: 1765
Abstract Category|Abstract Category(s): Clinical and Translational Science Network
Authors
  • Liu, Sean Shih-yao  ( Indiana University School of Dentistry, Indianapolis, IN, USA )
  • Brown, Ryan  ( Private Practice, Avon, IN, USA )
  • Chu, Tien-min Gabriel  ( Indiana University School of Dentistry, Indianapolis, IN, USA )
  • Katona, Thomas  ( Indiana University School of Dentistry, Indianapolis, IN, USA )
  • Stewart, Kelton  ( Indiana University, Indianapolis, IN, USA )
  • SESSION INFORMATION
    Poster Session
    Clinical and Translational Research
    03/22/2013