A comprehensive lecture on orthodontic archwires by Dr Rashid Hassan. Four types of alloys are used to treat the malaligned teeth in orthodontics. For video lectures Follow Dr Rashid Lectures on Dental Materials on Facebook (dmbydrrashid) or visit www.drrashidlectures.com.

1. By
Dr. RASHID HASSAN
BDS(de’ Mont) MSc (QMUL.UK)
Hod Science of Dental Materials

2. ARCHWIRES commonly used are
1) Stainless Steel Wires.
2) Chrome Cobalt Wires.
3) Nickel Titanium Wires.
4) Beta Titanium Wires.

3. Available in Round,
Square & Rectangular
shapes
Available sizes are
 Round:0.012˝,0.014˝,0.01
6˝,0.018˝ & 0.020˝
 Square:0.016˝x0.016˝
 Rectangular:0.016˝x0.0
22˝, 0.017˝x0.022˝,
0.017˝x0.025˝, 0.019x0.025,
0.021˝x0.025˝
Steel + Chromium (12%-25%) = Stainless Steel

4. ADVANTAGES
1) Biocompatible.
2) Can withstand
occlusal forces.
3) Can be cold worked.
4) Highly ductile &
malleable.
5) Good formability.
6) Corrosion resistant.

5. DISADVANTAGES
1) Lower springback.
2) Frequent activations.
3) Higher forces.
4) Soldering problem.

6. COMPOSITION
i. Cobalt = 40%
ii. Chromium = 20%
iii. Nickel = 15%
iv. Molybedinium = 07%
v. Manganese = 2.0%
vi. Carbon = 0.15%
vii. Beryllium = 0.4%
viii. Iron = 15%

7. Cobalt+Chromium+Nickel+Molybedinium+Manganese
+Carbon+Beryllium+Iron
ADVANTAGES
1) Biocompatible.
2) Tarnish & corrosion
resistant.
3) Excellent formability.
4) Greater resistance to
fatigue.

8. DISADVANTAGES
1) Gets hard.
2) No cold working.
3) Loss of yeild &
tensile strength.
4) Discomfort during
tooth movement.

9. . Also called as
NiTiNOL
(Nickel Titanium Naval Ordinance
Laboratory)
Shape Memory
Property

10. ADVANTAGES
1) Excellent resiliency.
2) Springback property.
3) Very low forces.
4) Low load deflection.

11. DISADVANTAGES
1) Lack of formability.
2) May hurt buccal
mucosa.
3) Brittleness.
4) Expansive.

12. Introduced in 1981
Also called as TMA.
Composed of:
Titanium = 77.8%
Molebdenium = 11.3%
Zirconium = 6.6%
Tin = 4.3%

13. ADVANTAGES
1) Biocompatible.
2) Balanced properties.
3) Easily twisted.
4) Excellent formability.
5) True weldability.
6) Deliver low
biomechanical forces.
7) Tarnish & corrosion
resistance.

14. DISADVANTAGES
1) High surface
toughness
2) Expansive

17. Dr. RASHID HASSAN
BDS(de’ Mont) MSc (QMUL.UK)
Hod Science of Dental Materials