A small catalog about the wires ,properties and thier uses in orthodontics

1. Dr Mohammed basheer Naha

2. CONTENTS
INTRODUCTION
GENERAL PROPERTIES OF ORTHODONTIC WIRES
MANUFACTURE OF ORTHODONTIC WIRES
GOLD ALLOYS
STAINLESS STEEL WIRES
AUSTRALIAN WIRES
CHROME-COBALT ALLOY WIRES
TITANIUM BASED ALLOY WIRES
AESTHETIC WIRES
NEWER ORTHODONTIC WIRES
CONCLUSION
REFERENCES

3. INTRODUCTION
• The main components of an orthodontic appliance -brackets and wires.
• In engineering terms , a wire is a flexible structural or machine component having a working length many
times of its cross sectional dimension and has the capability of transmitting force along its length (
Nikolai RJ orthodontic biomaterials)

4. Seminars in orthodontics 1997 issue 3 Angle orthod 2002 issue 72

5. ROBERT BOB KUSY
(1947– 2008)
• a leader in applying engineering
principles to orthodontic materials and
techniques,
• Of his more than 200
articles in the research literature, nearly half
were on
orthodontic topics.
• Among his wide array of contributions
were mechanics-oriented treatments of the
behaviour of orthodontic wires in bending and
torsion.

6. History of the Evolution of Materials
Material Scarcity,
Abundance of Ideas
(1750-1930)
Abundance of
materials, Refinement
of Procedures (1930 –
1975).
The beginning of
Selectivity (1975 to
the present)

7. Material Scarcity, Abundance of Ideas (1750-1930)
• Before Angle’s search;
• Noble metals and their alloys.
- Gold (at least 75%), platinum, iridium and silver alloys
 Good corrosion resistance
 Acceptable esthetics
 Lacked flexibility and tensile strength
 Inappropriate for complex machining and joining.

8. • Angle (1887)  German silver (a
type of brass)
• “according to the use for which it
was intended”-varying the
proportion of Cu, Ni & Zn and
various degrees of cold work
• Angle listed few materials
appropriate for work:
 Strips of wire of precious metals.
 Wood
 Rubber
 Vulcanite
 Piano wire
 Silk thread

10. Abundance of materials, Refinement of Procedures (1930 – 1975)
• Stainless steel was introduced in 1934
• Improvement in metallurgy and organic chemistry – mass production(1960).
• Cobalt chrome (1950s)-Elgin watch company developed a complex alloy-
Cobalt(40%),Chromium(20%),iron(16%)&nickel(15%).
• Rocky Mountain Orthodontics- ElgiloyTM
• 1962 - Buehler discovers nickel-titanium dubbed NITINOL (Nickel Titanium
Naval Ordnance Laboratory)
• 1970-Dr.George Andreason (Unitek) introduced NiTi to orthodontics.

11. The beginning of Selectivity (1975 to the present)
• Orthodontic manufacturers
• CAD/CAM – larger production runs
• Composites and Ceramics
• Iatrogenic damage

Nickel and en-masse detachments
new products-control of government agencies, private organizations

12. β titanium –Burstone and Goldberg-1980
• Composition
• Ti – 80%
• Molybdenum – 11.5%
• Zirconium – 6%
• Tin – 4.5%
• Titanium-Niobium- M. Dalstra et al.
 Nickel free Titanium alloy.
 Finishing wire.
 Ti-74%,Nb-13%,Zr-13%.

13. Evans TJW , durning P ( BJO 1996) divided the phases of archwire
development into five phases on the basis of 3 characteristics:
•Method of force delivery.
•Force / deflection
characteristics.
•Materials.

14. Method of force
delivery
Force/deflection
characterstics
Materials
Phase I Variation in arch Linear force/ Gold
wire dimension deflection ratio
Phase II Variation in Linear force/ Stainless steel,
material but same deflection ratio NiTi, Co-Cr
dimension
Phase III Variation in arch Non linear force Beta titanium
wire diameter deflection (stress
induced structural
change)

15. Phase IV
Variation in
Structural composition
of wire Non linear force
deflection(thermally
Thermally activated
nickel titanium
induced structural
change)
Phase V Variation in wire Non linear force Graded thermally
composition / deflection(thermally activated nickel
structure induced structural titanium.
change)

16. Basic Properties of Materials
• To gain understanding of orthodontic
wires – basic knowledge of their
atomic or molecular structure and
their behavior during handling and
use in the oral environment .

17. ATOM - smallest piece of an element that keeps its chemical properties
ELEMENT - substance that cannot be broken down by chemical reactions
ION - electrically charged atom (i.e., excess positive or negative charge)
COMPOUND - substance that can be broken into elements by chemical reactions
MOLECULE - smallest piece of a compound that keeps its chemical properties (made of two
or more atoms)

18. Electrons – orbit around
nucleus.
Floating in shells of diff
energy levels
Electrons form the basis
of bonds

19. CRYSTALS
• Many materials, like glass, exhibit similar properties in all
directions. These types of materials are known as amorphous
materials the property is known as isotropy
Lattices
• The three dimensional arrangement of lines that can be
visualized as connecting the atoms in undisrupted crystals, is
called a lattice. A lattice is actually a large 3-dimensional
structure

20. Materials broadly subdivided into 2 categories -
Atomic arrangement
Crystalline structure Non-crystalline structure
Regularly spaced Possess short range
config-space lattice. atomic order.
Anisotropic –diff in Isotropic-prop of material
mechanical prop due remains same in all
directional arrangement directions.
of atoms. Amorphous
ORTHODONTIC
MATERIALS ,
SCIENTIFIC AND
CLINICAL ASPECTS
WILLAM A .
BRANTLEY

21. There are 14 possible lattice forms.( Bravais lattices)
The unit cells of 3 kinds of space lattices of practical importance –
1.Face-centered
cubic
2.Body
centered cubic
3.Hexagonal
close packed:

22. 22
Basic Properties of Materials
Face-centered cubic:
Fe above 912°C
Stable iron known as austentite

23. Body centered cubic
Fe-below 910°C

24. Hexagonal close packed:
Co , Ti below 880 C

25. Twinning
• Many of the closed packed hexagonal type of
crystals undergo a type of deformation called
twinning.
• The crystal is divided into two symmetric halves
• NiTi is characterized by multiple twinnings
throughout its structure.
• When the alloy is subjected to a higher
temperature, de twinning occurs, and the alloy
returns to its original shape or size (shape memory)

26. Polymorphism
• Many metals and alloys exist as more than one type of structure. These forms
can usually change from one to the other. This is known as allotropy
• Example : at higher temp IRON has FCC structure
at lower temp IRON has BCC structure

27. Transition of iron
• Iron – 2 forms-
• FCC-above 910°c
• BCC-below-Carbon practically insoluble.(0.02%)
• Iron  FCC form (austenite)
• Lattice spaces greater
• Carbon atom can easily be incorporated into the unit cell

28. Austenite (FCC)
slow cooling rapid cooling
Mixture of: Martensite / Ferrite(BCC)
distorted lattice-
& hard & brittle
Cementite(Fe3C)

29. • strengthening of a metal by plastic deformation.
• During deformation - atomic bonds within the crystal get stressed
 resistance to more deformation
work hardening or cold work
• Principle of work hardening hardness
•  Hard and strong, tensile strength
Brittle.
Work hardening

30. • Process of softening the metal to
reverse the effect of cold working
• Heating below the melting point.
• More the cold work, more rapid the
annealing
• Higher melting point – higher
annealing temp.
ANNEALING

32. AJODO 1989 , VOLUME 96

33. Stress &
strain
• Young’s modulus (modulus of elasticity)
• Range
• Springback
• Formability
• Resiliency
• Flexibility
Elastic
properties
•Proportional limit
•Yield strength
•Plastic deformation
•stiffness/load deflection rate
Strength
properties
Mechanical properties

34. STRESS
• When a force acts on body, tending to produce deformation, a resistance is
developed within the body to this external force. The internal resistance of the
body to the external force is called stress.
STRESS = F/A
Stress-internal distribution of load – force/ unit area
(Internal force intensity resisting the applied load)

35. Types of stress
• Tensile –stretch/pull
• Compressive – compress towards each other
• Shear – 2 non linear forces in opp direction which
causes sliding of one part of a body over another
• Complex stress - a single type of stress does not occur in
a wire there will be combination of stresses

37. Strain
• If the stress (internal resistance) produced is not sufficient to withstand the external
force (load) the body undergoes a change in shape (deformation). Each type of
stress is capable of producing a corresponding deformation in the body
Strain- internal distortion produced by the load-
deflection/unit length
(change in length/original length)
STRAIN = l/L
Strain can be elastic or plastic
Elastic strain can be reversible
Plastic strain is due to permanent displacement of atoms

38. Elastic properties
• Stress-Strain relationship
3 points on the stress strain graph can be represented to
explain “STRENGTH”
1. Proportional limit
2. Yield strength
3. Ultimate tensile strength

39. Proportional limit
• point at which first deformation is
seen
• Thus proportional stress can be defined
as the greatest stress that may be
produced in a material such that the
stress is directly proportional to strain.
• At this point if the stress is removed
the wire returns back to its original
form
Yield strength .
• To measure the proportional
Limit
• The limit of tolerable
permanent strain is the yield
strength
Ultimate tensile strength
• Max. load a wire can substain
• Is greater than the yield Strength
& occurs after Some plastic
deformation
• Clinically imp – determines
Max force a wire can deliver

40. ELASTIC LIMIT
elastic limit
may be defined as the maximum stress
that a material will withstand without
permanent deformation , such that it
returns to its original form

41. Modulus of elasticity (Young’s modulus)
• Measures the relative stiffness or rigidity of the wire
within elastic limit
• Modulus of elasticity = Stress/Strain
• Hooke’s law – stress and strain (elastic or
compressive) are proportional to each other
• Represented by a st.line designated as ‘E’
• Modulus of elasticity – constant for a given material

42. Stiffness and springback
-are proportional to ‘E’
stiffness α E ie load / deflection
springiness α 1/ E
springiness= 1/ stiffness
The more horizontal the slope the
more springier the wire, the more
vertical the slope the more stiffer
the wire
Stiffness Basically refers to the resistance of the wire to deformation
Low stiffness implies that wire will deliver low forces
Spring back is the extent to which a wire recovers its shape after
deactivation

43. Range – distance the wire will bend elastically
before permanent deformation occurs( not exceeding the clinical
limits of the wire
measured up to the yield strength on X axis

44. Relationship b/w strength, stiffness & range
Clinically optimal spring back occurs when the wire is bent b/w its elastic limit and
ultimate strength
The greater the spring back, the more the wire can be activated
Ultimate strength = stiffness x range
Strength is defined as the force required to activate the arhcwire
Clinical implication

45. • Resiliency – represents the energy storage capacity of the wire
• Higher resilient wire will exert force for a longer time and sustain
activation for long
Strength + springiness
• wire is stretched- space between the atoms increases.
• Within the elastic limit, there is an attractive force between the atoms
Resiliency

46. It is represented by the area under the stress strain graph upto the proportional limit.
Resiliency

47. Formability
• This property describes the ease with which a material may be permanently
deformed .
• Indication of the permanent bending the wire will tolerate while bent into
springs , arch forms etc
• Also an indication of the amount of cold work that they can withstand

48. Formability
• It is represented by the area under the stress strain graph b/w the yield strength
and fracture point.

49. Other mechanical properties
1. Flexibility
2. Toughness
3. Brittleness
4. Fatigue

50. Flexibility
• large deformation (or large strain) with minimal force, within its elastic limit
FLEXIBLE
• Maximal flexibility is the strain that occurs when a wire is stressed to its elastic
limit.
Max. flexibility = Proportional limit
Modulus of elasticity.

51.  Toughness –force required to fracture a material. Total area
under the stress – strain graph.
 Brittleness –opposite of toughness. A brittle material, is
elastic, but cannot undergo plastic deformation.
 Fatigue – Repeated cyclic stress of a given magnitude below
the fracture point. This is called fatigue.

52. Requirements of an ideal arch wire
Robert P.Kusy- 1997 (AO)
1. Esthetics
2. Stiffness
3. Strength
4. Range
5. Springback
6. Formability
7. Resiliency
8. Coefficient of friction
9. Biohostability
10. Biocompatibility
11. Weldability

53. According to profit
• The ideal properties for an orthodontic purpose
1. High strength.
2. Low stiffness.
3. High range.
4. High formability.

54. Esthetic
• Desirable
• Manufacturers tried-coating -White coloured wires
• Deformed by masticatory loads
• Destroyed by oral enzymes
• Uncoated-transparent wires-poor mechanical properties
• Function>Esthetics
• Except the composite wires

55. Stiffness / Load –Deflection Rate
• Proffit: - Slope of stress-strain curve
• Thurow - Force:Distance ratio, measure of resistance to deformation.
• Burstone – Stiffness is related to – wire property & appliance design
Wire property is related to – Material & cross section.
• Wilcock – Stiffness α Load /deflection Magnitude of the force delivered by
the appliance for a particular amount of deflection

56. Low stiffness or Low LDR implies that:-
1) Low forces will be applied
2) More constant force delivery as the appliance deactivates
3) Greater ease and accuracy in applying a given force

57. Strength
• Yield strength, proportional limit and ultimate tensile & compressive strength
• Kusy - Force required to activate an archwire to a specific distance.
• Proffit - Strength = stiffness x range.
• Range limits the amount the wire can be bent, stiffness is the indication of the
force required to reach that limit.

58. Range
• Distance that the wire bends elastically, before permanent deformation occurs
(Proffit).
• Kusy – Distance to which an arch wire can be activated- working range.
• Thurow – A linear measure of how far a wire or material can be deformed
without exceeding the limits of the material

59. Springback
• Proffit – the ratio of yield strength and modulus of elasticity YS/E
• Kusy - The extent to which a wire recovers its shape after deactivation
• Large springback - Activated to a large extent.
• Hence it will mean fewer archwire changes.

60. Formability
 Kusy – the ease in which
a material may be
permanently deformed.
 Ease of forming a spring
or archwire
 Proffit: amount of
permanent deformation a
wire can withstand
without breaking
Store/absorb more strain energy /unit volume before they get
permanently deformed
Greater resistance to permanent deformation
Release of greater amount of energy on deactivation
High work availability to move the teeth
Resiliency

61. Coefficient of friction
• Brackets (and teeth) must be able to slide along the wire
• Independent of saliva-hydrodynamic boundary layer
• High amounts of friction  anchor loss.

62. Biohostability
• Site for accumulation of bacteria, spores or viruses.
• An ideal archwire must have poor biohostability.
• Should not-actively nurture nor passively act as a substrate for micro-
organisms/spores/viruses
• Foul smell, discolouration, build up of material-compromise mechanical
properties.

63. Biocompatibility
• Ability of a material to elicit an appropriate biological response in a given
application in the body
• Wires-resist corrosion –products – harmful
• Allergies
• Tissue tolerance

64. Weldability
• Process of fusing 2 or more metal parts though application of heat, pressure or
both with/out a filler metal to produce a localized union across an interface.
• Wires –should be easily weldable with other metals

65. Factors affecting the elastic properties of the wire
Cross section of the wire
Length of the wire
Type of attachment

66. How does change in size and shape of wire
effect stiffness, strength & springiness?
• Considering a cantilever beam;

67. Cross section of the wire
• Changing the diameter of the wire no matter how it is supported greatly affects its
properties but vary in their magnitude.
In doubling the cross section:
• Strength - 8 times stronger ( i.e. increases by cubic function)
• Springiness – Decreases by a factor of 16 (i.e. Decreases by 4th power function)
• Range – Decreases by factor of 2 (i.e. it decreases proportionately)

68. Length of the wire
If length is doubled-
• Strength – Decreases in half
• Springiness – Increases by a factor of 8
• Range – Increases by a factor of 4
In the case of torsion, the picture is slightly
different. Increase in length –
• Stiffness decreases proportionately
• Range increases proportionately
• Strength remains unchanged

69. Type of attachment
• In the case of a cantilever, the stiffness of a wire is obviously less, as it is
supported from only one side. If the wire is supported from both sides
• Supporting the wire in both ends
• Strength – Increases twice
• Springiness - decreases by a factor of 4
• Range - Decreases in half

70. Physical properties
• Corrosion
Chemical or electrochemical process in which a solid, usually a
metal, is attacked by an environmental agent, resulting in partial or complete
dissolution.
• Not merely a surface deposit –deterioration of metal
• Localized corrosion-mechanical failure
• Biological effects-corrosion products

71. Types of corrosion
• Uniform attack
• Pitting Corrosion
• Crevice corrosion or Gasket corrosion
• Galvanic corrosion
• Intergranular corrosion
• Fretting corrosion
• Microbiologically influenced corrosion
• Stress corrosion
• Fatigue corrosion

72. 1. Uniform attack –
 Commonest type
• The entire wire reacts with the environment
• Hydroxides or organometallic compounds
• Detectable after a large amount of metal is dissolved.
2. Pitting Corrosion –
• Manufacturing defects
• Sites of easy attack

73. • Excessive porous surface-as received wires
Steel NiTi

74. 3.Crevice corrosion or gasket corrosion -
• Parts of the wire exposed to corrosive environment
• Non-metallic parts to metal (sites of tying)
• Difference in metal ion or oxygen concentration
• Plaque build up  disturbs the regeneration of the passivating layer
• Depth of crevice-reach upto 2-5 mm
• High amount of metals can be dissolved in the mouth.

75. 4.Galvanic /Electrochemical Corrosion
• Two metals are joined
• Or even the same metal after different type of treatment are joined
• Difference in the reactivity 
Galvanic cell.
 
Less Reactive More Reactive
(Cathodic) (Anodic) less noble metal

76. 5. Intergranular corrosion
• Sensitization - Precipitation of CrC-grain boundaries
-Solubility of chromium carbide
6.Fretting corrosion
 Material under load
 Wire and brackets contact –slot – archwire interface
Friction  surface destruction
 Cold welding -pressure  rupture at contact points-wear oxidation
pattern

77. 7.Microbiologically influenced corrosion (MIC)
• Sulfate reducing-Bacteroides corrodens
• Craters in the bracket
• Certain bacteria dissolve metals directly form the wires.
• Or by products alter the microenvironment-accelerating corrosion

78. 8.Stress corrosion
• Similar to galvanic corrosion-electrochemical potential difference-specific sites
• Bending of wires - different degrees of tension and compression develops locally
• Sites-act as anodes and cathodes.

79. 9.Corrosion Fatigue:
• Cyclic stressing of a wire-aging
• Resistance to fracture decreases
• Accelerated in a corrosive medium such as saliva
• Wires left intraorally-extended periods of time under load

81. Manufacture of orthodontic wires
• In order to use newer wires, a proper understanding of the manufacturing
process and their effect on physical properties is necessary
• Alloy is a metallic intimately mixed solid mixture of two or more different
elements one of which is at least essentially a metal

82. Requirements of an alloy
• chemical nature should not produce harmful toxic or allergenic effects
• chemical properties of the appliances should provide resistance to corrosion
• physical and mechanical properties such as strength, modulus of elasticity,
coefficient of thermal expansion, conductivity should all be satisfactory
• technical expertise needed for fabrication and use should be feasible
• metals, alloys and companion materials for fabrication should be inexpensive
and readily available

83. Different methods used to prepare alloys are:
Fusion method
Electro deposition
Reduction method
Powder metallurgy or compression method

84. • Thurow (1982) has described the steps in manufacturing process as follows:
• Melting.
• Ingot formation.
• Rolling.
• Drawing.

85. • Melting
-Selection and melting of alloy materials-important
-Physical properties influenced
-Fixes the general properties of the metal
• The Ingot
-Critical step- pouring the molten alloy into mold
- Non –uniform chunk of metal
- Varying degrees of porosities and inclusions of slag

86. • Rolling
- 1st mechanical step-rolling ingot –long bars
-Series of rollers – reduced to small diameter
-Different parts of ingot never completely lose identity
-Metal on outside of ingot-outside the finest wire, likewise ends
- Different pieces of wire same ingot differ depending on the part they came
from
-Individual grains also retain identity

87. Each grain elongated in the same proportion as the ingot
-Mechanical rolling-forces crystals into long finger-like shapes –meshed into one
another
-Work hardening-increases the hardness and brittleness
-if excess rolling-small cracks
-Annealing –atoms become mobile-internal stresses relieved
-More uniform than original casting
-Grain size controlled

88. • Drawing
-Further reduced to final size
-Precise process –wire pulled through a small hole in a die
- Hole slightly smaller than the starting diameter of the wire –
uniformly squeezed
-Wire reduced to the size of die
Many series of dies
- Annealed several times at regular intervals
Exact number of drafts and annealing cycles depends on the alloy (gold
<carbon steel<stainless steel)

89. • Process of manufacture
• Spinner Straightening
• It is the mechanical process of straightening resistant materials, usually in the cold
drawn condition. The wire is pulled through rotating bronze rollers that torsionally
twist it into straight condition.
• Pulse Straightening
• Found by Mr. A.J. Wilcock. The wire is pulsed in special machines that permit
high tensile wires to be straightened.
• The advantages of pulse straightening over other methods are:
• It permits the highest tensile wire to be straightened.
• The material tensile yield stress is not suppressed in any way.
• The wire has a much smoother appearance and hence less bracket friction

90. • Steel is an alloy of iron and carbon , Steel = iron + carbon >2.1%

92. ARCHWIRE MATERIALS
I. Gold
2. Stainless Steel
3. Chrome- Cobalt
4. Nickel – Titanium
(i) Super elastic
(ii) Thermodynamic or temperature transforming
5. Beta Titanium
6. Alpha Titanium
7. Composite / coated arch wires
8. Titanium niobium arch wire
9.Newer niti wires
10.Nickel free stainless steel and other modifications

93. INTRODUCTION
GENERAL PROPERTIES OF ORTHODONTIC WIRES
GOLD ALLOYS
STAINLESS STEEL WIRES
AUSTRALIAN WIRES
CHROME-COBALT ALLOY WIRES
TITANIUM BASED ALLOY WIRES
AESTHETIC WIRES
NEWER ORTHODONTIC WIRES
CONCLUSION
REFERENCES

94. Cross section of arch wires

95. Wire dimensions are ,According to the
(ISO) 15841
• Some time Deutsches institut Fur Normung ( german standards ) are followed
Round wires
• 0.010 inch
• 0.012 inch
• 0.014 inch
• 0.018 inch
• 0.020 inch
• 0.022 inch

96. Rectangular wires
• 0.016 x 0.022 inch
• 0.017 x 0.025 inch
• 0.018 x 0.025 inch
• 0.019 x 0.025 inch
• 0.0125 x 0.0275 inch
dimensions

97. Gold alloy wires
• Prior to the 1950’s precious metal alloys were routinely used for orthodontic
purposes.
• The gold alloy wire compositions were generally similar to those of the type IV gold
casting alloys.
• The typical composition of the alloy is as follows:-
• Gold – 15 – 65% (55-65% more typical)
• Copper – 11 – 18%
• Silver – 10 – 25%
• Nickel – 5 – 10%

98. Properties of gold alloys
• Pure gold by itself is too soft for all dental purposes, its alloys can be used in
orthodontics.
• easily joined by soldering and the joints are very corrosion resistant.

99. ADVANTAGES DISADVANTAGES
• Excellent biocompatibility
• Easily joined by soldering
• Good formability
• Capable of delivering lower forces than stainless
steel
• Excellent corrosion resistance
• High cost
• Low yield strength
• Low spring back

101. The evolution on stainless steel
This is the most popular wire in orthodontics because of its low cost and possesses many
qualities that is desired for orthodontic treatment
Stainless steel is an alloy of iron. It was discovered accidentally by Sheffield metallurgist Harry
Bearly during World War I days.
It entered dentistry in 1919, introduced at Krupps dental polyclinic in Germany by F. Hemptmey
who first used it to make a prosthesis and called the alloy Wipla (German: like platinum)
Angle used it in his last years as ligature wires
By 1937 the value of stainless steel as an orthodontic material had been confirmed
By the 1960s, gold was universally abandoned in favor of stainless steel

102. STAINLESS STEEL
• When 12-30% chromium is added to steel the alloy is commonly called stainless
steel.
Compositon
• 18% chromium
• 8% Nickel
• 71% iron
• 0.2% carbon
• Titanium, Manganese (2%) Silicon (1%) Sulfur (0.15%), Molybdenum,
Phosphorus, Niobium and Tantalum.

103. • Chromium :
The corrosion resistance of stainless steel is largely due to the passivating effect of
chromium.
• Nickel:
Alloying with nickel improves the corrosion resistance to oxidizing acids
• Carbon: Provides strength and hardness and it increases corrosion.
• Silicon: Improves resistance to oxidation

104. • Sulphur: Allows easy machining of the alloy parts.
• Manganese: Stabilizes the austenitic phase, but it
decreases the corrosion resistance.
• Molybdenum: Improve the corrosion resistance to non
oxidizing acid and salts.

105. Classification
American Iron
and Steel
Institute (AISI)
Unified
Number
System (UNS)
German
Standards
(DIN).
No’s range from 300 – 502
No’s having ‘L’ signify low carbon content
higher the number, more the iron content

106. 3 major types are present
Ferretic SS Martensitic SS Austenitic SS
400 series
Good corrosion resistance <
strength
Share 400 series
Have high strength & hardness
300 series
Most corrosion resistant
Not hardenable by heat
treatment or cold work
Can be heat treated Contain approx
18 – 20 % Cr
8 – 12% Ni
18-8 steel
Industrial purposes Surgical and cutting instruments Type 302 & 304
Orthodontic wires and bands

107. Austenitic steels (the 300 series)
(18 – 8 steels )
• Most corrosion resistance
• FCC structure,  non ferromagnetic
• Not stable at room temperature,
• Austenite stabilizers Ni, Mn and N
• Type 302-basic alloy -17-18% Cr, 8% Ni, 0.15%-C

108. Austenitic steels more preferable because of The following
properties
Greater ductility
and malleability
More cold work-
strengthened
Ease –welding
Desensitization
Ease in forming

109. • Both austenite and ferrite grains
• Fe,Mo,Cr, lower nickel content
• Increased toughness and ductility than ferritic steels
• Twice the yield strength of austenitic steels
• High corrosion resistant
• Manufacturing of low nickel attachments-one piece brackets

110. Advantages disadvantages
• Maintain the positions of teeth & hold
the corrections achieved
• Begg treatment, stiff arch wire, to
dissipate the adverse effects of third
stage auxiliaries
• Force required to engage a steel wire
into a severely mal-aligned tooth.
Either cause the bracket to pop out,
Or the patient to experience pain.
• Overcome by using thinner wires, which
have a lower stiffness.
• Not much control.

111. Stainless steel
General properties
Relatively stiff material
• Yield strength and stiffness can be varied
• Altering diameter/cross section
• Altering the carbon content and
• Cold working and
• Annealing
• High forces - dissipate over a very short amount of deactivation (high load
deflection rate).

112. Lowest frictional resistance
 Ideal choice of wire during space closure with sliding mechanics
 Teeth will be held in their corrected relation
 Minimum resistance to sliding

113. High corrosion resistance
• Ni is used as an austenite stabilizer.
• Not strongly bonded to produce a chemical compound.
• Symptoms in sensitized patients

114. Sensitization
• During soldering or welding, 400 - 900 oc
• Reduces the corrosion resistance -Sensitization
• Diffusion of Chromium carbide towards the carbon rich areas (usually the grain
boundaries)

115. Stabilization– methods to overcome sensitization
• One or two elements that form carbide precipitates more easily than Chromium
are added
• Eg titanium, tantalum or niobium
• Expensive – not used for orthodontic wires
Routinely
• Lower carbon content – no carbide precipitates are formed
• Use of low fusing solders
• Minimizing time and area of soldering

119. Aligning & Levelling
Round S-S with loops Great range and light forces are req
Multistranded S-S
Retraction
Rectangular S-S
Finishing
Rectangular S-S More stability & less tooth movement reqd

120. Multistranded wires
• They are composed of specified numbers of thin wire sections coiled around
each other to provide round or rectangular cross section
• The wires-twisted or braided
• When twisted around a core wire-coaxial wire

121. Multistranded wires
Co-axial
Twisted wire
Multi braided

126. • Some of the multistranded wires:
• Twist flex – Unitek
• Force 9 – Ormco
• D – rect – Ormco
• Respond – Ormco

127. studies done on these wires
Kusy ( AJO-DO 1984)
• Compared the elastic properties of triple stranded SS
wire with SS, NiTi & β -Ti
• Stiffness was comparable to 0.010 SS wire but
strength was 20% higher & stiffness 25% more
• The multistranded wire did not resemble the 0.018
wire in any way except for the size and & bracket
relation
Results

128. • Oltjen,Duncanson,Nanda,Currier (AO-1997)
• Wire stiffness can be altered by not only changing
the size or alloy composition but by varying the
number of strands.
• Increase in No. of strands  stiffness
• Unlike single stranded wires

130. history
World War II, American supplies of orthodontic appliances and materials to Australia became
doubtful and as a consequence,
a group of eminent dentists and metallurgists formed a committee to consider manufacture in
Australia.
Early part of Dr. Begg’s career
Arthur Wilcock Sr.
Begg s needed Wires which would remain active for long
No frequent visits
This lead Wilcock to develop steel wires of high tensile strength.

131. • Beginners found it difficult to use the highest tensile wires
• Grading system
• Late 1950s, the grades available were –
• Regular(at the low end)
• Regular plus
• Special (the middle of the range)
• Special plus(at the high end)
• By the early ‘1970s’the demand worldwide for these wires had been increased
• So it allowed them to make more grades like Premium, premium +, supreme

132. Drawbacks of the wires :
The impossibility with existing methods to straighten the
highest tensile wires for subsequent forming into appliances.
Work softening occurring in the wires that were being
straightened.
The conventional wire forming concepts were not appropriate
to the unique wire. So the highest tensile wires kept breaking.

133. Manufacture
of the wires
Spinner
straightening
Pulse
straightening

134. Spinner straightening
• It is mechanical process of straightening resistant materials in the cold drawn
condition.
• The wire is pulled through rotating bronze rollers that torsionally twist it into
straight condition.
• Disadvantages:
• Decreases yield strength
• Creates rougher surface

135. Pulse straightening
• Newer method developed after 1980 to overcome the drawbacks
• Placed in special machines that permits high tensile wires to be straightened.
Advantages:
1. Permits the straightening of high tensile wires
2. Does not reduce the yield strength of the wire
3. Results in a smoother wire, hence less wire – bracket friction.

136. • difficulty in straightening and work softening, were largely overcome using
this new process.
• However for the third shortcoming i.e. breakage on bending, Wilcock Jr. has
made the following recommendations:

137. Ways of preventing fracture
1.Bending the wire around the flat beak of the pliers.
-Introduces a moment about the thumb and wire gripping point, which reduces the applied stress on the wire.
2. The wire should not be held tightly in the beaks of the pliers.
Area of permanent deformation to be slightly enlarged
3.Wilcock-Begg light wire pliers, preferably not tungsten carbide tipped
The edges rounded  reduce the stress concentration in the wire.
Ductile – brittle transition temperature slightly above room temperature.
Wire should be warmed.

139. The wires are graded and color coded
depending upon the resiliency:
Regular with white label
Regular plus with green label
Special grade with black label
Special plus with orange label
Premium with blue label [formerly
known as Extra special plus
Premium plus
Supreme grade

140. Regular Grade (White label)
• Lowest grade
• Easiest to bend
• Used for practice bending & forming auxiliaries

141. Regular Plus (Green label)
• Used for auxiliaries and arch wires when more
pressure and resistance to deformation are desired
Special Grade (Black Label)
• Highly resilient
• Used for starting arch wires in many techniques

142. Special Plus (Orange Label)
• Highly resilient
• Routinely used in deep bite correction
• But bending is difficult as brittle

143. Extra Special Plus Grade
• Also referred to as premium plus
• This is unequalled in resiliency & hardness
• More difficult to bend & more subjected to fracture
• Extra special plus’s ability to
move teeth, open bites and
resist deformation are excellent

144. Supreme Grade (Blue label)
• Further developed by Mr. A.J. Wilcock Jr. in 1982
• Is Ultra light tensile fine round stainless steel wire
• Was initially introduced in the 0.10” diameter and this was
further reduced to 0.09” diameter
• Is primarily used in early treatment for rotation, alignment
and levelling

145. The new grades available are:
Premium .020”
Premium plus .010”, .011”, .012”, .014”,
.016”,0.18”
Supreme .008”, .009”, .010”, .011”

146. Properties of Australian wires
• The ultimate tensile strength for pulse-straightened wires is 8-12% higher than
stainless steel wires indicating greater resistance to fracture in oral cavity.
• The pulse-straightened wires have a significantly higher working range and recovery
patterns.
• Frictional resistance of the pulse-straightened wires is lesser by a factor of 50% then
stainless steel wires.
• They also have the property of zero stress relaxation.

147. Zero Stress Relaxation
• If a wire is deformed and held in a fixed position, the stress in the
wire may diminish with time, but the strain remains constant.
• Property of a wire to deliver a constant light elastic force, when
subjected to external forces (like occlusal forces).
• Only wires with high yield strength-possess this desirable property
• Materials with high YS-resist such dislocations-internal frictional
force.
• New wires-maintain their configuration-forces generated are
unaffected

148. BAUSCHINGER EFFECT
• Described by Dr. Bauschinger in 1886.
• Material strained beyond its yield point in
one direction & then strained in the reverse
direction, its yield strength in the reverse
direction is reduced.
• result in situations exposing the metal
workpiece to stresses of reversed sign.
• enabling greater cold drawability of the
workpiece

149. Methods of increasing yield strength of Australian wires.
1. Work hardening
2. Solid solution strengthening
3. Grain refinement and orientation

150. Fracture of wires & Crack propagation
High tensile wires have high density of dislocations and crystal defects

Pile up, and form a minute crack

Stress concentration

Sensitization
Small stress applied with the plier beaks

Crack propagation

Fracture of wire

151. Studies on Australian wires
• Twelftree, Cocks and Sims (AJO 1977)
Premium plus, Premium and Special plus
wires showed minimal stress relaxation
Jothindra kumar comapred the working range of australian wires with SS and cocluded that it has the best range
J Ind Orthod Soc, 20, 251 “ 264(1989)

154. Conclusion
• ultimate tensile strength as compared to the corresponding wires.
• Higher range
• Lesser coefficient of friction
• Surface area seems to be rougher than that of the other manufacturers’
wires.
• Lowest stress relaxation.

156. History
• developed during 1950’s by the Elgiloy Corporation (Elgin. IL.USA)
• This alloy was originally used for watch springs by Elgin Watch Company
• Rocky Mountain Orthodontics - Elgiloy
• Marketed as Elgiloy, Azurloy, multiphase, Ramaloy

157. Compositon
• Co-40%
• Cr-15%
• Ni-7% - strength & ductility
• 15% Iron.
• Molybdenum -7%,
• Manganese 2%
• Carbon 0.15%,
• Beryllium 0.4%
rocky mountain®orthodontics

158. Chrome cobalt alloy wires in four tempers
• Blue Elgiloy
• Yellow Elgiloy
• Green Elgiloy
• Red Elgiloy
rocky mountain®orthodontics

159. Eligiloy properties
• Set resistance – Retains power longer than stainless steel
• Fatigue resistance – More cycles than stainless steel without breakage
• Greater spring efficiency – Up to 20% more power than spring steel without an
increase in dimensions
• Corrosion resistance – Outperforms chrome stainless steel by 17%
• Non-magnetic – Non-magnetic through all temperature ranges
rocky mountain®orthodontics

160. Blue Elgiloy
• It is the softest of the four wire temper and can be bent easily with
fingers or pliers.
• It is recommended for use when considerable bending, soldering and
welding is required.
• Heat treatment of blue elgiloy increases its resistance to deformation.
• Excellent for edgewise arches, lingual arches, retainers and removables.
rocky mountain®orthodontics

161. Yellow Elgiloy
• It is relatively ductile and more resilient than blue
elgiloy.
• It can also be bent with relative ease.
• Further increase in its resilience and spring
performance can be achieved by heat treatment.
• Yellow Elgiloy is recommended
• where greater spring qualities are needed than those provided by Blue Elgiloy
rocky mountain®orthodontics

162. Green Elgiloy
• It is more resilient than yellow elgiloy and can be shaped
with pliers before heat treatment.
Red Elgiloy
• is initially “hard
• Most resilient and has high spring qualities.
• Heat treatment makes it extremely resilient
• Used where adjustments will not be required after heat-treating
rocky mountain®orthodontics

163. 1. Delivered in different degrees of hardening or
tempers
2. High formability
3.Further hardened by heat treatment
4.Greater resistance to fatigue and distortion
5.Longer function as a resilient spring

164. Applications in orthodontics

170. Titanium based wires
BETA TITANIUM ALPHA TITANIUM
TIMOLIUM
NICKEL TITANIUM
ALLOYS

171. BETA TITANIUM WIRES (TITANIUM
MOLYBDENUM ALLOY OR T.M.A)
• It was introduced to
orthodontics as TMA by
burstone and Goldberg in the
1980s
• Goldberg and Burstone
demonstrated that, with proper
processing of 11%
molybdenum, 6% Zirconium
and 4% tin beta titanium alloy,
it is possible to develop an
orthodontic wire

172. alloying titanium with molybdenum stabilize Ti in beta phase at room
temp
Titanium - 73.5%
Molybdenum - 11.5%
Zirconium - 6%
Tin - 4.5 %

173. Properties of β – Titanium wires
• They show high flexibility and recover their shape fully from the initial
deformation
• Have low modulus of elasticity , lower forcer will be produced even for
larger activations
• Very resilient wire , has high tensile strength , T , and l loops can be
formed in both round wire and rectangular wire

174. • High corrosion resistant
• Can be welded or soldered with ease
• Wires show passivating effect due to the presence of
titanium oxide .

175. Clinical application
Rectangular TMA used during retraction
stages .
Closing loops
K-SIR ARCH WIRE.0.019’’/0.025’’

176. • Ideal edgewise arches
• Direct welding of auxiliaries
• Beta-titanium’s balance of physical properties also makes it an ideal choice for
utility arches

177. • Ormco has introduced a low friction T.M.A. featuring
dramatically reduced coefficient of friction for
superior sliding mechanics
• Ormco has introduced TMA colors that use oxygen
and nitrogen ion implantation.
• With this method it is possible to have wires of
different colors

179. ALPHA TITANIUM
• usually referred to as a near-alpha alloy.
• The alpha titanium alloys is attained by adding 6% aluminum and 4% vanadium to
titanium.
Compositon
• TITANIUM - 90%
• ALUMINIUM - 6%
• VANADIUM - 4%
PROPERTIES:
 Heat treated to improve strength.
 Satisfactory creep properties - Finishing & braking arches.
 Wire becomes hard in the oral environment due to hydrogen
absorption.

180. Not very popular due to :
• Poor workability
• Poor formability
• Brittleness
• Hight cost
MAINLY USED FOR ROOT TORQUING IN FINISHING STAGES

181. TIMOLIUM WIRES
• This Alpha-Beta titanium alloy is introduced recently by TP orthodontics.
• When compared to Nickel Titanium or Beta Titanium wire, Timolium
outperforms in the following:
• More resistant to breakage
• Smoother for reduced friction
• Brightly polished and aesthetically pleasing
• Nickel free for sensitive patients
• Easier to bend and shape

182. Uses
• Timolium wire is excellent for all phases of treatment
• During initial treatment, it is excellent for tooth alignment, levelling and bite
opening.
• Early torque control during intermediate treatment
• Total control during detailing makes Timolium the wire of choice during the
final treatment phase.

183. Studies done on timolium
• Compared with SS and BETA
titanium
• Timolium was poor in its weld
characteristics with large voids and
wide gaps at the welded area
AO 2004

185. History
In the late 60s the office of the navy was actively studying about alloys ,that exhibited
shape memory effect ,
of one these showed great promise , they dubbed it as ‘NITINOL’ (naval ordnance
laboratory )
At around 1970 Dr George Andersen recognized the potential
With the help of UNITEK it was marketed as NITINOL ™
Niti wires were introduced in orthodontics in the year 1971

186. Martensite stabilized alloys ( M – NiTi )
Martensite active alloy.
Austenitic- active wires. (A – NiTi)

187. Martensite stabilized alloys ( M – NiTi)
• Stable martensitic structure
• These do not possess shape memory or super elasticity (e.g. Nitinol).
Martensite active alloy.
• These alloys employ thermoelastic shape memory effect
• oral environment raises the temp of the deformed archwire in martensite phase to transform into stable
austenite form. (e.g. Copper NiTi)

188. Austenitic- active alloys (A – NiTi)
• These alloys have both super elastic & shape memory effect
• (e.g. Chinese NiTi & Japanese NiTi ).
• wire exerts about the same force whether it is deflected a relatively small or
a large distance which is a unique & extremely desirable property.

189. properties of nickel titanium alloys
Shape memory
Super elasticity
Hysteresis

190. Shape memory
• Shape memory refers to
the ability of the material
to “remember” its original
shape after being
plastically deformed while
in the martensitic form
• This property is also
called Thermoelasticity.
Super elasticity
• Abilty of a wire to deliver a
near constant force over a
wide range of activation
• If stress is induced in the
nickel-titanium alloy
the austenitic form changed to a
martensitic form
• Kusy termed this also as
pseudo elasticity

192. Hysteresis
• When the austenitic nickel-titanium wire is stressed,
• it can be observed that the loading curve differs from its unloading curve.
• This reversibility has an energy loss associated with it, this is known as
hysteresis.

193. NI-TI alloys used frequently due to :
• Low modulus of elasticity
• Excellent load deflection properties
• Better yield strength
• Greater working range
• Formability
• High corrosion resistance

194. Uses of NiTi wires:
• NiTi is the ideal wires for initial leveling and aligning ,
• rectangular NiTi allows full engagment of the bracket slot and gives better torque
control in initial phase of treatment
• Reverse curve NiTi, also known as rocking chair NiTi helps in the bite opening
• Titanium alloys offers a significant improvement over currently available
material for tooth separation, Re use after autoclaving is also possible with NiTi
springs.
• NiTi palatal expander has been developed which is used for transverse expansion
of the maxilla.

195. • Closed coil springs deliver ideal forces for Class II intra-arch maxillary
retraction as well as other space closure and maintenance applications
• Open coil springs open and maintain space gently and efficiently in a
convenient cut to length design.

196. Trade names of niti alloy wires manufactured by
some companies
• `Elastinol– Masel Orthodontics
• Bioforce sentalloy – GAC International
• Nitanium – Ortho Organisers
• Neo sentalloy – GAC International
• TITANAL XR – Masel Orthodontics
• Rematitian – Dentaurum
• Nitinol SE – Unitek
• Nitinol XL—Unitek
• Turbo – Ormco
• Orthonol – Rocky Mountain
• Marsenol – T.P.Orthodontics
• Reflex – T.P. Orthodontics
• Sentinol – GAC International
• Align – A company
• FORCE I—American Orthodontics

197. NITINOL ( conventional nickel titanium wires)
AJO Feb 1978

198. • Nitinol ( Early 1960s) - William.F.Buehler, a research metallurgist at the Naval
Ordnance Lab in Silver Springs, Maryland
(Now called the Naval Surface Weapons Center)
Ni - Nickel
Ti - Titanium
Nol - Naval ordnance laboratory

202. RETRANOL
Retranol ‘The Bite Opener’ reverse curve archwires, are
produced from work hardened NiTi.
This wire provides a greater working range than SS wires
and affords ideal dimensional stability to avoid dumping
the anterior during retraction
Throughout treatment, retranol remains active without
deforming. Available in round and rectangular, upper and
lower arch forms.

204. LIMITATIONS
• It will readily break when bent over a sharp edge.
• The bending of loops or omega bends are not recommended. ( especially closing
loops ).
• Bending of tie-back hooks entails a high risk of failure.

205. CHINESE NITI WIRE
AJO JUNE 1985
New NiTi by Dr.Tien Hua Cheng and
associates at the General Research
Institute for non Ferrous Metals, in
Beijing, China.

206. Properties of Chinese niti
CANTILEVER APPARATUS 0.016 SS, Nitinol and chinese-NiTi
were submitted to a flexural test
 STIFFNESS
 SPRINGBACK
 MAXIMUM MOMENT
 Temperature ch
Angular deflection measured by protractor.

207. SPRING BACK
For 80º activation
SS - 16º
Nitinol - 52º
Chinese NiTi - 73º
Arch Wire - Same force
- “Unique and Extremely desirable
Chinese NiTi wire has 1.4 times the springback of nitinol
wire and 4.6 times the springback of stainless steel wire.

208. STIFFNESS
Activation and reactivation curves.
Chinese NiTi at 80° activation has an average stiffness that is 73%
that of 45 % Stainless Steel & 36% that of Nitinol.

209. TEMPERATURE DEPENDENT CHANGES
• Chinese NiTi wire, exhibits some small differences at
varying temperatures because material components have
lower transition temperatures.
increased temp = increased stiffness
= reduced spring back
• the wire is normally used between room temperature and
mouth temperature, these temperature-dependent effects are
clinically insignificant.

210. TIME DEPENDANT CHANGES
• over 1 minute, the Chinese NiTi wire deformed a limited amount, compared to the nitinol and stainless
steel wires which deformed considerably.
• Although NiTi wires show some time-dependent effects, these are insignificant at room temperature.

211. CLINICAL SIGNIFICANCE
• Applicable in situations where large deflections are required.
• When tooth are badly malpositoned.
• Niti wire deformation is not time dependent

212. JAPANESE NITI
- Fujio Miura et al ( AJODO July 1986)
In1978Furukawa electric
co.ltd of Japan produced
a new type of alloy
1. High spring back.
2. Shape memory.
3. Super elasticity.

213. The report concluded about Examination of
mechanical property of the wire.
1. Tensile test
2. Bending test
Measurements of the influence of special heat
treatment on the wire

214. Tensile test
• Co-Cr-Ni, Nitinol ,
Ss and Japanese NiTi.
• 0.016 wire
• Superelasticity.

215. Bending test
Different 0.016 wires

216. CLINICAL IMPLICATIONS
• Alignment of badly malposed teeth
• Distalize the molar
• Expansion of arch
• Gain/Close the space
• Periodontally compromised pts

219. SUPER CABLE
• Supercable, comprises seven individual strands that are woven together in a
long, gentle spiral to maximize flexibility and minimize force delivery - Jeff
Berger (JCO 1998)

220. Clinical uses of super cable
• 0.016" and 0.018" Supercable wires were the only ones that tested at less than 100g of unloading force
over a deflection range of 1-3mm.
• Relatively large archwire like 0.18” can be placed at the starting of treatment.
• When cutting Supercable, always use a sharp distal end cutter (No. 619). A dull cutter tends to tear the
component wires and thus unravel the wire ends.

221. ADVANTAGES DISADVANATGES
Improved treatment efficiency.
Elimination of archwire bending.
Flexibility and ease of engagement regardless of
crowding.
No evidence of anchorage loss.
A light, continuous level of force, preventing any
adverse response of the supporting periodontium.
Minimal patient discomfort after initial archwire
placement.
Fewer patient visits, due to longer archwire
activation.
Tendency of wire ends to fray if not cut with
sharp instruments.
Tendency of archwires to break and unravel in
extraction spaces
Inability to accommodate bends, steps, or
helices.
Tendency of wire ends to migrate distally and
occasionally irritate soft tissues as severely
crowded or displaced teeth begin to align

224. COPPER NiTi
• Introduced by Rohit sachdeva
• It has the advantage of generating
more constant forces than any other
super elastic nickel titanium alloys.
• More resistant to deformation.
• Smaller mechanical hysteresis

225. CLASSIFICATION
Type I Af – 150 c
Type II Af - 270 c
Type III Af - 350c
Type IV Af - 400c

226. Type I Af – 150 c
• appear to generate forces required for root movement,
Type II Af - 270 c
• wire generates the highest forces of the three (Types II, III, IV) and
is best used in patients who have an average or higher pain
threshold, normal periodontal health and
• patients where the force system generated by the orthodontic arch
wire is constant, rapid tooth movement is required

227. Type III Wire-Af 35°C
• This wire generates forces in the midrange and is best used in patients who have
a low to normal pain threshold,
• compromised periodontium and when relatively low forces are desired.
Type IV wire – Af 40°C
These wires generate tooth-driving forces only when the mouth-temperature
exceeds 40°C,
• indications for use of this alloy include patients who are sensitive to pain,
compromised periodontal conditions and where tooth movement is deliberately
slowed down

228. ADVANTAGES OF COPPER NiTi ALLOYS
OVER OTHER NiTi WIRES
1. Smaller loading force for the same degree of deformation. (20% less )
2. Reduced hysteresis makes to exert consistent tooth movement and reduced
trauma.

230. OPTIFLEX
POLYNORBOGEN
TEFLON COATED WIRES
BIOFORCE ARCH WIRES
ORGANIC POLYMER WIRE (QCM)

231. Optiflex
• Optiflex is a non metallic orthodontic arch wire designed by Dr. Talass and
manufactured by Ormco.
• made of clear optical fiber

232. 3 layers
• A silicon dioxide core that provides the force for moving tooth.
• A silicon resin middle layer that protects the core form moisture and adds
strength.
• A strain resistant nylon outer layer that prevents damage to the wire and further
increases strength.

233. Advantages
• It the most esthetic orthodontic arch wire.
• It is completely stain resistant,
• Its effective in moving teeth using light continuous force
• Optiflex is very flexible , it has an extremely wide range of actions
• Due to superior properties optiflex can be used with any bracket system

234. Clinical applications
• It is used in adult patients who wish that their braces not be really visible for
reasons related to personal concern’s or professional consideration.
• Can be used as initial archwire in cases with moderate amounts of crowding in
one or both arches.
• Opti-flex is not an ideal archwire for major bicuspid retraction.

235. POLYNORBOGEN
• It is a shape memory plastic developed in Japan
• the temperature exceeds the transition temperature; it began to display an elastic
property and then returns to its original shape.
• At 50ºC, it can be starched to 2 to 3 times its original length.

236. TEFLON COATED WIRES
• Epoxy coated archwire:
It is tooth colored archwire.
It has a superior wear resistance and color stability of 4 to 8 weeks.
• Lee white wire:
Manufactured by LEE pharmaceutical,
It is a resilient SS or NiTi archwire bonded to a colored coating,
suitable for use with ceramic and plastic brackets.

237. • Marsenol:
a tooth colored NiTi wire.
It exhibits all the same working charac- teristics of an uncoated super elastic NiTi wire.
• Orthocosmetic elastinol
esthetically coated high performance NiTi super elastic archwire.
It is blends exceptionally well with ceramic or plastic brackets.
Titanium tooth toned archwire:
It is a super elastic NiTi wire with special plastic and friction reducing tooth colored coating.
It blends well with natural dentition, ceramic, plastic and composite brackets.

238. • Imagination wire:
This wire was introduced by Gastenco in Sweden.
It offers superior esthetics, hypoallergic.
wires are available as round, rectangular and square.
• Teflon coated stainless steel archwires:
Teflon coating imparts to the wire a hue which is similar to that of natural teeth.
Teflon coating protects the underlying wire from the corrosion process.

239. BIOFORCE ARCH WIRES
• bioForce arch wires have the unique property of delivering remarkably accurate
and biologically correct forces,
• The NiTi BioForce wires apply low, gentle forces to the anteriors and increasingly
stronger forces across the posteriors until plateauing at the molars.
• Beginning at approximately 100 grams and increasing to approximately 300
grams,
• BioForce provides the right force to each tooth, reducing the number of wire
changes and providing greater patient comfort.

240. ORGANIC POLYMER WIRE
• Organic polymer retainer wire made from 1.6mm diameter round polytheline
terephthalate
• Patients who have worn esthetic ceramic or plastic brackets during orthodontic
treatment are likely to want esthetic retainers after treatment, so these wires are
used for esthetic maxillary retainers.

241. Newer orthodontic wires

242. DUAL FLEX WIRES
• Type I
• Type II
• Type III

243. • Type I - The dual flex-1, the anterior segment made up of 0.016 titanol (ni-ti alloy), the
posterior segment made up of 0.016 SS.
• The flexibility of the anterior segment provides easy bracket engagement and
• the rigid posterior segment controls rotation movements, prevents tipping, and permit
bite opening.
• useful with the lingual appliance, where anterior interbracket width is greatly reduced

244. • Type II –
• The dual flex-2, the anterior segment made up of .016x.022 rectangular titanol wire and the
posterior segment of 0.018 SS.
• It is used in cases where it do not need all of the extraction space closed by anterior retraction.
The anterior segment impedes movement of anterior teeth while the extraction space is closed
by the mesial movement the posterior teeth.

245. • Type III - The dual flex-3, however, consists of a flexible anterior part of a
0.017 x 0.025-inch titanic rectangular wire and a posterior part of 0.018 square
steel wires.
• establish anterior anchorage and control molar rotation during the closure of
posterior spaces. They also initiate the anterior torque

246. BIO TWIST NITI
• The bio twist is a 0.021 × 0.025 pre-form rectangular arch wire formed with multiple strands
of titanium super elastic wire. This multistrand structure gives the wire
• low force and low stiffness with excellent flexibility, and the rectangular shape allows
significant engagement of the slot.
• Bio twist wire is great for use at the beginning of treatment during the unraveling stage
because it will facilitate levelling and aligning while also controlling torque.

247. NITANIUM TOOTH TONE PLASTIC COATED ARCHWIRE
• These are stain and crack resistant
• .They are plastic and the friction reducing tooth colored coating blend with natural
dentition as well as ceramic, plastic and composite brackets.
• These wires blend in with tooth anatomy and esthetic brackets to further enhance the
visual appeal of esthetic bracket systems.
• And it delivers 29 to 150 grams of force on teeth.

248. TRIFORCE WIRE
• Implantation – Nitriding.
• Advantage it makes titanium more esthetic
• It is a pre programmed wire to deliver the right amount of force for each area of mouth. It
delivers high forces to molars, medium force to bicuspids and light force to incisors.
• These wires are austenitic wires and delivers force constantly. It prevents unwanted
rotations of premolars and gentle force to anterior causing no discomfort.
• It provides three dimensional controls from the beginning of the treatment.

249. MEDICAL GRADE TITANIUM
• Metal allergies are common in dentistry, sometimes patient gets inflamed
gingival, puffy face and breathing problem.
• Pure titanium are as sturdy as SS but contain no copper, nickel,
molybdenum/chromium to eliminate all allergies. Ideal for sensitive patient.

250. TRIANGULAR WIRES
• Broussard and Graham in 2001 introduced SS triangular wire
• The triangular wires are equi- lateral triangle in cross-section of 0.030" to a side
with rounded edges
• These wires can be used for making retainer, removal appliance and bonded
lingual retainer.

251. DEAD SOFT SECURITY ARCHWIRE
• It has been introduced by Binder and Scott. In a non- extraction case,
• an archwire is usually placed to initiate tooth movement immediately after
bonding.
• in an extraction case a proper archwire might create undesired tooth movement
before extraction are performed.
• This problem can be avoided by placing sectional arches made of dead soft brass
wire or twisted double strand of 0.008" or 0.010" dead soft SS ligature wire.

252. GOLD NITI WIRES
• A NiTi wire coated with super hard gold 24 carat
• Allows silky smooth sliding mechanics and gives a fabulous rich look.

253. L SHAPED NITI WIRES
• It has deeper curve of spee thus makes easier to open the bite,

254. Conclusion
• Fundamental principals and properties of orthodontic arch wires should be
known by an Orthodontist ,
• The right selection of these materials is essential for proper clinical practice

255. References
• Proffit W R; Contemporary Orthodontics
• William A Brantley : Orthodontic materials-scientific and clinical aspects
• OP Kharbhanda
• Catalogs , Ormco , AO , 3m unitek , GH wires
• Robert P Kusy;A review of contemporary arch wires; Their properties and characteristics’
Angle Orthod, 1997;67(3);197-208
• Kusy Orthodontic biomaterials: From the past to the present-AJO May 2002
• Twelftree, Cocks, Sims. Tensile properties of Orthodontic wires. AJO 89;72:682-687
• Kapila & Sachdeva. Mechanical properties and clinical applications of orthodontic wires. AJO
89;96:100-109.

256. • Charles J Burstone&AJ Goldberg;Beta Titanium;A new orthodontic alloy;AMJ
Orthod 1980;77:121-132.
• Wilcock AJ;Applied materials engineering for orthodontic wires; Aust Orthod
J,1989;11(1);22-29
• Andreasen GF& Marrow RE;Laboratory &clinical analysis of nitinol wire;AMJ
Orthod 1978;73;142-151
• Charles J Burstone,Qin&Morton;Chinese Niti wire;A new orthodontic alloy;AMJ
Orthod 1985;87;445-451
• Fujio Miura,Mogi,Ohura&Hamanaka;The super-elastic property of the Japanese
NiTi alloy wire for use in orthodontics;AMJ Orthod Dentofac Orthop,1986;90;1-10