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Strength decay of orthodontic elastomeric ligatures
T V Lam1, T J Freer, P J Brockhurst
1University of Queensland, Australia.
Journal of Orthodontics
|March 22, 2002
Summary
Clear and colored elastomeric ligatures showed varying tensile strength (TS) decay over 12 weeks. Brand differences were noted, with Unitek ligatures generally outperforming Ormco in TS.
Area of Science:
- Orthodontic materials science
- Biomaterials engineering
Background:
- Elastomeric ligatures are crucial in orthodontic treatment for applying continuous force.
- Understanding the degradation of mechanical properties, such as tensile strength (TS), is essential for predicting treatment duration and efficacy.
Purpose of the Study:
- To evaluate the tensile strength (TS) and extension to TS of clear and colored elastomeric ligatures from two companies over a 12-week period.
Main Methods:
- An ex vivo study was conducted using seven replicates of five ligatures per company.
- A simulated clinical situation was employed to test ligature properties.
Main Results:
- All tested ligatures demonstrated a gradual decrease in TS over the 12 weeks.
- Unitek ligatures generally showed higher TS compared to Ormco ligatures.
- An increase in extension to TS was observed for most ligatures over time, with no detrimental long-term effects from pre-stretching.
Conclusions:
- Significant differences in TS and extension to TS exist between clear and colored elastomeric ligatures.
- Brand-specific variations in mechanical properties among elastomeric ligatures were confirmed.
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