Recent advances in orthodontic wires /certified fixed orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


OVERVIEW
 INTRODUCTION.
 HISTORICAL PRESPECTIVE.
 PHYSICAL AND MECHANICAL
PROPERTIES.



INTRODUCTION
The materials used by orthodontists have changed
rapidly in recent years and will continue to do so in
the future.
As esthetic composite archwires are introduced,
metallic archwires will likely be replaced.
Because an ideal material has not yet been found,
archwires should be selected within the context of
their intended use during treatment.

Ideally, archwire are designed to move teeth with
light, continuous forces. Such forces may reduce the
potential for patient discomfort, tissue hyalinization
and undermining resorption
When force is applied, the archwire should behave
elastically over a period of weeks to months.
several properties and characteristics should be
considered in the search for the ideal archwire.


Among them are esthetics, biohostability,
friction, formability, weldability, resilience, and
springback.

Currently, orthodontists principally use wires of
four major base metal alloys types: Stainless steel
Cobalt-chromium-nickel, Nickel-titanium and
Beta-titanium www.indiandentalacademy.com

HISTORICAL PRESPECTIVE
Gold alloys were first used in orthodontic practice,
although these noble metal wires have minimal
use currently because of their greater cost.
Their compositions were similar to base metal
wires precisely to IV gold casting alloy
Gold alloy wires had elastic force
was much less than that of S.S.


With the advent of Stainless steels in World War I
and the refinement of drawing processes to form wires
in the late 1930s, gold archwires gradually lost favor to
the smaller cross-sectional areas that stainless steel
archwires can produce.
By 1950s stainless steel alloy was used by most of
the orthodontist
It has low cost, excellent
formability and good
mechanical property.

PHYSICAL AND MECHANICAL
PROPERTIES
STRESS: It is a internal distribution of the load
measured as force per unit area.
STRAIN: It is the internal distortion produced by the
load ,force defined as deflection per unit area.
PROPORTIONAL LIMIT OR ELASTIC LIMIT :The
point at which first elastic deformation occurs
LDR OR STIFFNESS: For a given force deflection
within the elastic limit is known as LDR

SPRING BACK: spring back is a measure of how far
a wire can deflect without permanent deformation.
STIFFNESS: It is a measure of amount of force
Required to produce a specific deformation.
STRENGTH: STIFFNESS X RANGE
RESILIENCE: Represents energy stored capacity of
wire which is a combination of strength and
springness

FORMABILITY: The ability to bend a wire into desired
configuration into loop, coil and stops without
fracturing the wire.
FLEXIBILITY: The amount which a wire can be
strained under going plastic deformation
ZERO STRESS RELAXATION: This the ability of
the wire to deliver constant high elastic force when
subjected to external force or force of occlusion.


SRESS RELAXATION: When a specimen has been
deformed and held in a fixed position the stress may
diminish, with time this is called as stress relaxation
COLD-WORKING: The process of plastically
deforming a metal at a temperature below that at which
it recrystallizes new grains, which is usually one-third
To one-half times its absolute melting point temperature
HEAT TREATMENT: General process of using
Thermal energy to change the characteristics of
metallicalloys as in tempering, precipitation hardening
, or annealing (a high-temperature, softening process).

PHASE TRANSFORMATION: A change in the number
and/or character of the phases that constitute the
microstructure of an alloy by a change in crystalline
structure.
RANGE - The distance that an archwire can be
activated by a specific force, this distance is termed the
“working” range.
-With regard to elastic property ratios the distance
that an archwire can be activated elastically
i.e., its elastic range.

EFFCT OF SIZE AND SHAPE ON
ELASTIC PROPERTIES
Major elastic properties namely-Strength, stiffness
and range is substantially effected by a change in
the geometry of beam.
Cross-section (circular, rectangular or square)
and length of the beam are of great significance in
determining its properties


EFFECT OF DIAMETER OR CROSS-SECTION

Add fig 10-12 pg 335 proffit


EFFECT OF LENGTH AND ATTACHMENT
If length of cantilever beam is doubled, its bending
strength becomes ½ , and springiness increases
by 8 times
Length effect on torsion quite differently
-springiness and range as length increases
-Torsional strength is not effected by length
Supported beam on both end has more strength
but less springiness

Add fig pg 336 proffit


EFFECT OF CHANGING VARIOUS ASPECT
OF ARCHWIRE


FROM
WILLIAM.R.PROFFIT
II edition

This alloy consists of 18%chromium ,8%nickel
alloyed with austenitic type of stainless steel.
Cr and ni maintains the austenite at room
temp.And prevents the conversion fcc structure of
austenite to martenisitic cubic lattice structure.
By nature austenite is malleable and ductile
and martenisite is hard and brittle

BRAIDED AND TWISTED WIRES
Very small diameter s.s wire can be braided or
twisted together by the manufacturer to form wires
for clinical orthodontics.
Separate strands may be as small as 0.005 or
0.010, comprised of five or seven wrapped around a
central wire of same diameter.
It affords extreme flexibility and delivers extremely
light forces, full engagement of the arch wire at an
early stage.

Used at the beginning of the treatment to align
labiolingually displaced or rotated anterior teeth.
These wires are available with bright smooth finish
to give minimal friction.
They resist permanent deformation and not unravel
when cut.
They are cost efficient wires in comparison to
titanium wires.

They are available in both round and rectangular
shape.
Different type of multi-stranded wires are available
1. Triple stranded – 3 wires twisted
2. Coaxial – 5 wires wrapped around a core wire
3. Braded – 8 strand rectangular wire.


Stainless steel arch-wire with
soldered brass wire
Used for sliding mechanics
ADVANTAGES
Minimal chair side time.
More efficient sliding of
arch wire through posterior
slot
No running out of space
for activation

DISADVANTAGES
Confusion concerning ideal force level.
Tendency to over activate elastic forces.
Insufficient force.
Damaged or crushed bracket inhibits sliding.
Cortical bone resistance due to thinning of
bone at extraction site.


AUSTRALIAN ORTHODONTIC ARCH WIRE
Claude Arthur j wilcock produced this wire for
Dr.P.R.Begg
The unique charecteristics of this wire are it is
high Tensile austenitic stainless steel.
The wire is resistant to permanent deformation ,
maintaining its activation for max. control of
anchorage.


All these properties make this wire very hard
and brittle.
MANUFACTURING PROCEDURE
pulse straightening the wire is pulsed in a special
machine which permits high tensile wires to be
straightened and drawn in as smaller diametres as
possible.
The material yeild strength is not altered and the
surface has smoother finish so less friction.

PROPERTIES OF WIRE
1. The tensile strength of the P.S wire is 8-12% higher
than of S.S so greater resistance to fracture.
2. The LDR was high by 10%for 0.016 ps wire and by
235% to 0.020premium wires indicates that when
used for intrusion they deliver significant higher
loads
3. High working range and good recovery patterns.
4. Frictional resistence of ps wires were lesser by
50%than s.s wires.

GRADING AND COLOUR CODING
- OLDER WIRES
1. REGULAR GRADE- WHITE LABEL
2. REGULAR PLUS- GREEN LABEL
3. SPECIAL GRADE- BLACK LABEL
4. SPECIAL PLUS- ORANGE LABEL
5. EXTRA SPECIAL PLUS- BLUE LABEL


NEWER WILCOCK WIRES
Newer grade of wires came to market with superior
properties with advent in manufacturing process
they are1. PREMIUM - PURPLE
2. PREMIUM PLUS – GOLD
3. SUPREME - BEIGE


PREMIUM GRADE
They are more difficult to bend, occasional breakage
to be expected.
They are efficient to open the bite.
PREMIUM PLUS
The 0.014 premium plus wire is used
in high angle cases to prevent
undue molar extrusion and due to
less dia.donot produce much force
and and ant intrusion(not effective)
which is favourable in such cases.

SUPREME
Supreme grade wires are used to unravel crowding
of ant. teeth,maa,mini uprightining springs
They have resistance and yeild diameter near to
NI-TI wires and cost wise they are more economic.
when used as MAA the lighter forces produced do
not tax the anchorage.


Triangular Wire
The new stainless steel Tri-Angle wire is an
equilateral triangle in cross-section, .030" to a side,
with rounded edges.
One of the best uses for Tri-Ang
wire is in retainers and other
removable orthodontic appliances.
Various types of clasps made of round wire usually
cross the occlusion, creating interferences that can
cause patient discomfort.
JCO,2001 BY - BROUSSARD

The round wire can act as a wedge to cause
inter-proximal spacing, which can disrupt the
occlusion, with a potentially adverse effect on longterm stability.

Comfort , periodontal health, and appliance stability.

Bonded lingual retainers

Special plier for Tri-ang wire bending

NICKEL TITANIUM WIRES
Andersen G.F and co workers introduced the
use of NITI alloys for orthodontic use in 1970s
It consists of conventional NITI (55% nickel
45%titanium) ,resulting in 1 : 1 ratio of these
elements,cobalt is added to achieve desirable
properties.

UNIQUE PROPERTIES
Shape memory effect - The combination of
thermoelasticity and pseudoelasticity in which,
following a force-induced phase transformation, the
reverse transformation occurs, when the archwire
temperature is increased to oral temperature
Pseudoelasticity - The mechanical analog of
thermoelasticity in which, at constant temperature,
the austenitic-to-martensitic phase transformation
occurs with increasing applied force. As the force is
subsequently removed, the reverse phase
transformation occurs.

Thermoelasticity - The thermal analog of
pseudoelasticity in which the martensitic phase
transformation occurs from austenite as the
temperature is decreased. This phasetransformation
can be reversed by increasing the temperature to its
original value.
Phase transformation temperature –
1. Martensitic- on cooling ,Ms and Mf temperature are
the temp. at which the transformation to martensite
begins and is completed.


2.Austenitic- On heating As and Af are temp. at
which the transformation to austenite begins and
Compeleted.
3.Rhombohedral- It is a intermediate R-phase which
is formed during Martensite-Austenite phase, it also
has Rs and Rf phase.


SUPER ELASTIC WIRES
Nitinol wire is work hardened during the
manufacturing process which induces the martenistic
phase into the alloy hence super elasticity is not
exhibited by the nitinol wire.
The super elastic property of some niti wires has
been attributed to phase transformation from
Austenitic form to Martenistic form of niti when stress
reaches certain level during activation.


Upon deactivation the reverse phase
transformation from martenistic to austenitic
structure takes place.
It is thus necessary for the manufacturer to
leave ni-ti in austenitic structure for super elastic
behaviour.
The new super elastic ni ti (a-ni-ti) wires are
significantly different from earlier work hardened ni
ti(m-ni-ti)and from s.s
The combination of super elasticity and shape
memory makes these archwires comfortable for
the patients even as rect. intial arch wires.

Since the stiffnes increases and the wire
becomes more efficient towards the end of the
movement the clinician should not change the
wire too often,a two month appoint. interval is
sufficient or remove and place the same arch
wires at monthly interval which will return them
to their intial activation level.
Intial rect super elastic wires fully engaged for
rotation correction, alignment,levelling.


The original super elastic arch wires ,the round
sentalloy wires are available in light,medium,and
heavy force levels.
Neo-sentalloy wires at levels of 100,200,300
grams of forces.
The second generation ,squre or rectangular bio
force wires provides 80 gm of force in central
incisor region for tooth alignment and as much as
320gm of force in molar region for initial leveling.

The new bio force ion guard has 3micron
nitrogen coating that is produced by ion
bombardment of wire surface which reduces
friction, breakage and nickel release.
The most versatile wire of simultaneous
alignment and leveling.


CHINESE NITI
In1985 dr. burstone c.j. reportedof an alloy the
chinese ni-ti developed by dr.tien hua chang.
This alloy has unique charecteristics and offers
significant potential in the design of orthodontic
appliances.
It has low TTR than nitinol its history of little work
hardening in a parent phase which is austenitic
yield mechanical properties that differ significantly
from nitinol.

3 POINT DEFLECTION TEST


Because of this high range of action and spring
back chinese ni-ti is applied when large deflections
are required.
It has sprinback that is 4.4 times more compared
to stainless steel and 1.6 times that of nitinol.
Stiffness of this wire is 73%that of s.s and 36% that
of nitinol.
These wires are highly suitable if low stiffness is
required and large deflections are needed.

JAPANESE NITI
In 1986 miura f.etal reported Japanese NITI
,developed by furukowa electric comp.ltd. japan.in
1978
It posses excellent spring back ,shape memory
,super elasticity.
The delivered a constant force over an extended
portion of deactivation range and less likely to under
go permanent deformation.

It generates a physiological tooth movement bcoz of
relatively constant force delivered for a long period of
time during the deactivation of the wire
This super elasticity can be produced by stress and
not by temp.difference
Heat treatment at 500deg centigrade for 5 minutes
produced optimum super elasticity,this method is
inconvenient for clinical use
So, anew type of heat treatment reported by fujio
miura which is known as derht(direct electric
resistence heat treatment)

The chinese ni-ti and japanese ni-ti have a basic
austenitic grain structure and have a advantage of
transition in the internal structure with out
requiring a significant temp. change to accomplish
this.


In 1993, Hanson combined the mechanical
advantages of multistranded cables with the
material properties of superelastic wires to create a
superelastic nickel titanium coaxial wire.
This wire, called Supercable, comprises seven
individual strands that are woven together in a long,
gentle spiral to maximize flexibility and minimize
force delivery.
JCO 1998 ,BY- JEFF BERGER


FORCE DELIVERY TEST
A three-point bending test was carried out to
compare the force delivery of .016", .018", and .020“
Supercable with that of common nickel titanium
initial archwires.
Instron universal testing machine was used for
load deflection test.
All arch wires were loaded with a maximum
deflection of 4 mm, and then unloaded slowly

STUDY RESULTS
.016" and .018" Supercable wires exerted only
36-70% of the force of .014" solid nickel titanium
wires.
Comparing wires of the same diameter, .016"
Supercable demonstrated 65% less force than .
016" solid superelastic wires
while .018" Supercable exerted 78% less force
than .018“ solid superelastic archwires.

CLINICAL USES OF SUPER CABLE
.016" and .018" Supercable wires were the only
ones that tested at less than 100g of unloading
force over a deflection range of 1-3mm.
Supercable thus demonstrates optimum orthodontic
forces for the periodontium, as described by Reitan
and Rygh.


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.

END STOP

ADVANTAGES
• Improved treatment efficiency.
• Simplified mechanotherapy.
• 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.


DISADVANTAGES
• 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.

It is a new orthodontic wire designed by M.F.TALASS
It has high esthetic apperance with unique mechanical
properties. (manufactured by ORMCO)
It is made of clear optical fiber, it comprises 3 layers

1. A silicon dioxide core that provides the force for
moving teeth.

JCO,1992 BY- M.F.TALASS

2. A silicon resin middle layer that protects the core
from moisture and adds strength.
3. A stain-resistant nylon outer layer that prevents
damage to the wire and further increases its strength.

The wire can be either round or rectangular and is
manufactured in various sizes.

Mechanical properties
It has wide range of action and the ability to apply
light, continuous force.
Sharp bends must be avoided, since they could
fracture the core.
Optiflex has practically no deformation.


It is a highly resilient archwire that is especially
effective in the alignment of crowded teeth.

Optiflex possess 5 advantages, in terms of
esthetics
Optiflex is the most esthetic orthodontic arch wire.
Optiflex is completely stain resistant. The arch
wire will not stain or loose its clean look even after
several weeks in the mouth.

optiflex is very effective in moving the teeth using
light continuous force. It exerts about ½ the
force in comparison with other wire.
Optiflex is very flexible and can be used in severely
crowded teeth.
Due to its superior mechanical properties, optiflex
can be used with any bracket system.


When using optiflex, certain precautions
should be undertaken
Optiflex arch wires must be tied into the bracket
with elastomeric ligatures. Metal ligatures should
never be used since they fracture the glass core.
Sharp bend similar to those placed in metal
arch wire should never be attempt with optiflex.
These bends will immediately fracture the core.


It is recommended to use the (501) mini distal end
cutter. (AEZ) This cutter is especially designed to cut
all 3 layers of optiflex in the proper manner.
Inform your patient about the nature of optiflex and
its structure.Make sure they understand that rough
diet can harm the arch wire and delay treatment
progress.
Do not “cinch back” optiflex. You really don’t need
an cinch back since friction between elastomeric
ligatures and the outer surface of the arch wire will
eliminate unwanted sliding of the arch wire.

Clinical applications
It is used in adult patient who wishes that their
braces not be really visible for reason related to
personal concern or professional consideration.
It should be used in non-extraction cases as, it is
not the ideal wire for cuspid retraction in extraction
cases
optiflex has been disappointed in retracting
canine due to its limited ability to control the distal
tipping and labio lingual rotation of the retracted
cuspids.

Optiflex can be used in pre-surgical stage in cases,
which require orthodontic intervention.
Optiflex arch wire combined with translucent
brackets to create ultimate esthetics appliance.
Optiflex is available in 6 to 10 inch straight lengths of
0.017”and 0.021”
Optiflex arch wire showed low load deflection rates
reaching the proportional limit much earlier when
compared to other wires (braided stainless steel, niti,
cooper niti), It exerts 0.4698 grams for a defection of
4.46 mm.

Marsenol is a tooth colored nickel titanium wire
manufactured by glenroe technologies.It is E.T.E.
coated nickel titanium. (Elastomeric poly tetra flor
ethylene emulsion).
Marsenol exhibits all same working characteristics
of an uncoated super elastic nickel titanium wire.


The coating adhesive to the wire remains flexible.
The wire delivers constant forces over long periods
activation and is fracture resistant.

Leveling by extrusion (relative intrusion)
Exaggerated curve of spee in the
maxillary arch wire and reverse curve of
spee is placed in the lower arch wire


REVERSE CURVE
ARCH WIRE

LEE WHITE WIRE
Lee white wire, manufactured by Lee
pharmaceuticals is resilient stainless steel or
nickel titanium arch wire bonded to a tooth
colored Epoxy coating, suitable for use with
ceramic and plastic. The epoxy is completely
opaque and does not chip, peel, stain or
discolors.

organic polymer retainer wire made from 1.6mm
diameter round polytheline terephthalate.
This material can be bent with a plier, but will
return to its original shape if it is not heat–treated
for a few seconds at temperature less than 230°C
(melting point).

JCO,1996 BY- MIEKO WATANABE

In prefabricating the QCM retainer wires, the anterior
portion of the wire and the “wave” portion are
heat-treated at about 150°C immediately after bending.
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

Various parts of QMC retainer

Wire after heat-treated it displayed little deformation.
More shrinkage during heating was observed in the
posterior segment of the arch wire.

QMC WRAP-AROUND RETAINER
STEPS IN FABRICATION
2.
1.


3.

4.

5.


QMC WITH METAL POSTERIOR PORTION
1

2

3


QMC WITH ACTIVATIONLOOP


New Version of Esthetic Retainer (QMC)
New esthetics organic polymer.
The new version, easy to fabricate and fit to the
dental arch.
It requires no special tools or instruments only and
ordinary hair dyer.


It consists :
- Anterior plastic part
- A flat organic polymer wire with 10° labial torque
is attached to 0.032” stainless steel posterior arms,
each 11cm long.
Plastic portion comes in three intercanine
widths, with or without activating omega loops in
the posterior arms.


Thank you
For more details please visit


Recent advances in orthodontic wires /certified fixed orthodontic courses by Indian dental academy

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Recent advances in orthodontic wires /certified fixed orthodontic courses by Indian dental academy