Nickel titanium alloys /certified fixed orthodontic courses by Indian dental academy

ALLOYS
&
NEWER ORTHODONTIC
WIRES
INDIAN DENTAL
ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

NICKEL TITANIUM WIRES
“ To obtain fairly rapid tooth

movement, HYALINISED ZONES were
to be avoided or kept to a minimum.”
- REITAN


NICKEL TITANIUM WIRES
Ideally orthodontic wires are designed to move teeth
with light, continuous forces.





Stainless steel
Co-cr alloys
Beta titanium
Nickel titanium


NICKEL TITANIUM ALLOYS


Conventional - Nitinol



Superelastic
- Pseudoelastic – Japanese NiTi
-Thermoelastic – Cu NiTi


TITANIUM








Titanium was discovered by GREGOR
( England 1790 )
BOTHE et al implanted titanium in lab. animals
(1940)
A light weight metal
Atomic weight – 47.9
Non magnetic


TITANIUM





Corrosion resistant
Biocompatibility
High strength
Ductility
Two phages




Alpha
Beta

TITANIUM




Alpha phase – Hexagonal unit cells
At room temperature
Beta phase – Body centered cubic cells
At temperatures above 16200F or 8820C


TITANIUM






Alpha type – ALPHA TITANIUM (A.J. Wilcock)
Beta type – Beta II or ORMCO’ TMA
Titanium-Niobium wires
Both alpha & beta phases – Ti-Al-Fe & Ti-Al-V


TITANIUM
SUPERIOR CORROSION RESISTANCE
A thin complex film Tio2 gives Ti affinity, a self
adherence that may cause friction.
Titanium is not esthetic



Lacer aided depositions
Implantation of nitrogen ( IONGUARD )

NICKEL-TITANIUM ALLOYS
2 forms of NiTi alloys
1. Martensite - Body centered cubic/tetragonal lattice
2. Austenite – Face centered (close packed
hexagonal)
‘R’ phase – Rhombohedral
“SMART MATERIALS”

NICKEL-TITANIUM
TRANSITION TEMPERATURE RANGE
TTR above the body temperature renders the alloy
austenitic which is more rigid
TTR below the body temperature renders it martensitic
that is super elastic
Austenite wires - 2% of the strain range
Martensitic wires - 8%.

NICKEL-TITANIUM
HYSTERESIS
The range for most binary alloys is 400 – 600
Above the TTR the alloy is fully austenitic (Af),by
lowering the temperature martensite will form (Ms)
The temperature at which all the austenite is converted
to martensite is designated as martensite finish (Mf)

NICKEL-TITANIUM

PROPERTY

AUSTENITE

AUSTENITE

YIELD STRENGTH

560 MPa

100 MPa

ELASTIC
MODULUS

75 GPa

28 GPa


NICKEL-TITANIUM
Martensitic transformation of NiTi
FIDUCIARY
LINE


MARTENSITIC TRANSFORMATION
ADDDITIONS and IMPURITIES
Third metal can lower the TTR to as low as –3300F
or lower the Hysteresis
Thermally activated alloys contain third metal
(Cu,Co)
Small amounts of Al, Zr, Cr, or Fe will improve the
strength of the martensitic form


NICKEL-TITANIUM
Smaller atoms such as oxygen, nitrogen, and carbon
can not substitute for larger ones,but disrupt the
matrices
Ti4Ni2O4 inclusion, which lowers the alloy elasticity
(memory changes) interstitial oxygen causes NiTi
alloys to become susceptible to corrosion


MECHANICAL
PROPERTIES
Pseudoelasticity and thermoelasticity of nickel titanium
alloys: A clinically oriented review.Part I:Temparature
transitional changes
– SANTORO et al (AJODO June 2001)
SHAPE MEMORY

PSEUDOELASICITY
 SUPERELASTICITY



The crystal structure of the alloy will be confirmed by
means of RADIOGRAPHIC DEFRACTION or
DIFFERENCIAL SCANNING CALORIMETRY
STUDY OF RESISTIVITY


RESISTIVITY


SHAPE MEMORY
‘The ability of material to remember its original shape
after being plastically deformed’
A certain shape is set at elevated temperatures (above
the TTR).When the alloy is cooled below the TTR, it
can be plastically deformed but when it is heated
again the original shape is restored.


THERMOELASTICITY
Through deflection and repeated temperature cycles the
wire in the austenitic phase is able to memorise the
preformed shape
Ex; An orthodontic archform
By lowering the temperature the alloy is transformed
into martensite and becomes pliable and easily
deformed

PSEUDO ELASTICITY
A small percentage of martensite
( Intermediate Phase R ) is present in the grain
structure.
Under the conditions of stress “Stress induced
martensite ( SIM ) ” will be formed.
A LOCALISED STRESS RELATED SUPERELASTIC
PHENOMENON

SIM is unstable
In orthodontic clinical applications, SIM forms where
the wire is tied to brackets on malalligned teeth so
that the wire becomes pliable in deflected areas.
In those areas the wire will be super elastic untill
tooth movement occurs.


SUPERELASTICITY
The stress value remains fairly constant up to a certain
point of wire deformation. At the same time
deformation rebounds, the stress value remains
again constant.
It is determined by the typical crystallographic
characteristics of NiTi


STRESS-STRAIN CURVE
A-B shows elastic deformation
of the austenitic phase

B is the stress at which
martensite will form

C-D elastic deformation of
martensite



LOAD- DEFLECTION CURVE


The unique force deflection curve for A-NiTi wire occurs
because of a phase transition in grain structure from
austenite to martensite , in response not to a
temperature change but to applied force.
This transformation is a mechanical analogue to the
thermally induced shape memory effect.


CLASSIFICATION
NiTi orthodontic wires are generally classified as




NON SUPER ELASTIC ( M –NiTi )
Nitinol
SUPER ELASTIC ( A-NiTi )
Japanese NiTi ( Sentinol )


WATERS ( 1992 ) divided the compounds into 3 groups based
on their TTRs
1) Group I – Alloys with TTR between room temperature and
body temperature. ( Mart active alloys )
2) Group II - TTR below room temperature. (austenitic)
3) GROUP III – Alloys with TTR close to body temperature
which by virtue of the shape memory effect spring back to
their original shape when activated by body heat.


III) EVANS and DURNING introduced a even
more comprehensive classification of orthodontic
alloys dividing into 5 groups.
1) Phase
2) Phase
3) Phase
4) Phase
martensitic
5) Phase

1
– Including alloys like gold and ss.
II – Stabilised
III – Super elastic active austhentic
IV – Thermodynamic active
V

- Graded thermodynamic.


NITINOL
Laboratory and clinical Analysis Of Nitinol Wire
- G F. Andreasen, R E. Morrow ( AJO Feb 1978 )
Introduction of stainless steel wire appliances.
(1930- 1940)
Nitional ( Early 1960s) - William.F.Buehler, a
research metallurgist at the Naval Ordinance
Laboratory in Silver Springs, Maryland
( Now called the Naval Surface Weapons Center ).

NITINOL
Ni
Ti
Nol

– Nickel
– Titanium
- Naval ordinance laboratory

It was marketed by Unitek
Clinical use of Nitinol wire started in May 1972 by
G.F.ANDREASEN et al.


NITINOL
SHAPE MEMORY WIRE
Nitinol has the characteristic of being able
to return to a previously manufactured shape when it
is heated to a transition temperature range.
ELASTIC ORTHODONTIC WIRE
Compared with stainless steel Nitinol wire has an out
standing elasticity which is useful for orthodontic
applications.

NITINOL
In orthodontic applications
1 . Requires fewer arch wire changes.
2 . Requires less chair time.
3 . Shortens the time required to accomplish the
rotations and leveling
4 . Produces less patient discomfort.


NITINOL
PHYSICAL PROPERTIES.
Material property

Nitinol

Stainless steel

Alloy

Nickel, Titanium

Iron, Chrome,Nickel

Ultimate strength

230,000 to 250,000

280,000 to 300,000

p.s.i

p.s.i

Modulus of elasticity 4.8 x106 p.s.i


28.5 x 106 p.s.i

NITINOL
BEND TEST
A series of bend and torsion test have been performed
in accordance with the new ADA Specification no.32
on orthodontic wires .


NITINOL


NITINOL
TORSION TEST
A comparison between nitinol and stainless steel wires.


NITINOL
STORED ENERGY COMPARISONS
Stored energy of Nitinol wire is significantly greater
than an equivalent SS wire.this comparison was
based upon the wires being bent 90 degrees


NITINOL
CLINICAL APPLICATIONS
Class I ,II,III malocclusions in both extraction and non
extraction cases


NITINOL
The most important benefits from Nitinol wire are
realised when a rectangular wire is inserted early in
the treatment.
Simultaneous rotation, leveling, tipping,and torquing
can be accomplished earlier with a resilient
rectangular wire,
Cross bite correction
Uprighting impacted canines
Opening the bite

NITINOL
LIMITATIONS
1.Nitinol cannot be bent with sharp – cornered
instruments.
2. It will readily break when bent over a sharp edge.
3.The bending of loops or omega bends are not
recommended. ( especially closing loops ).

NITINOL
4 . Nitinol cannot be soldered or successfully welded
to it self with out annealing the wire, because the
bending of tieback hooks entails a high risk of
failure.
5 . Cinch – backs distal to the buccal tubes are easily
accomplished by flame annealing .Care should be
taken not to over heat the wire.


JAPANESE NITI
The super - elastic property of the Japanese NiTi
alloy wire for use in orthodontics.
- Fujio Miura et al ( AJODO July 1986 )
In 1978 Furukawa electric co.ltd of Japan
produced a new type of alloy
1. High spring back.
2. Shape memory.
3. Super elasticity.

JAPANESE NITI
TESTS
1. Examination of mechanical property of the wire.
1. Tensile test
2. Bending test
2. Measurements of the influence of specific treatment
on the wire.

JAPANESE NITI
1. Tensile test
Tensile testing was performed
first because it is the most
acceptable method.
Co-Cr-Ni, Nitinol ,
Ss and Japanese NiTi.


JAPANESE NITI


JAPANESE NITI
Bending test
3 point bending test was conducted in a specially
designed situation similar to the conditions involved in
moving teeth in the oral cavity.


JAPANESE NITI
Measurement of the influence of special
heat treatment on the wire.
A comparative analysis was conducted for this
property before and after being subjected to heat
using a .016 inch Japanese NiTi alloy wire.
Nitrate salt bath .
2000 c , 3000c, 4000c, 5000c, and 6000c.
5, 10, 60, and 120 min.
20 different variations.

JAPANESE NITI
RESULTS
The effects of temperature were negligible up to
5000c .
Super elasticity can be influenced by temperature
and time.
It is possible to modify the amount of orthodontic
force in an individualised segment of the arch wire.


CLINICAL IMPLICATIONS
0.016” medium preformed arch wire was tied into the
lateral incisor and canine bracket.
INITIAL

TWO MONTHS LATER


NITI COIL SPRINGS
TOOTH MOVEMENT RANGE- 0.5 mm per week .
Force range 75 to 100 gms.
NiTi coil springs .
The concept of NiTi coil springs was suggested in
1975.
1. Open coil springs.
2. Closed coil springs.

STUDIES ON THE JAPANESE NiTi ALLOY COIL
SPRINGS -F.Miura et al ( AJODO AUGUST 1988 )
study conducted to evaluate the efficiency and
mechanical properties of closed & open coils as well
as stainless steel coil springs.
10 mm Closed coil springs- tensile test .
50 mm Open coil spring- compression test.

FACTORS THAT AFFECT THE MECHANICAL
PROPERTIES OF SPRINGS.
1. Diameter of the wires α super elastic activity.
2. Size of the lumen 1/α super elastic activity.
3. Martensite transformation temperature α super
elastic activity.
4. Pitch of the open coil spring – when it is changed
from fine to coarse, the load value of super elastic
activity remains same but range increases.

Closed coil spring

After 5 months


Open coil spring

After 3 months


MOLAR DISTALIZATION WITH SUPER ELASTIC
NiTi WIRE.
- R.LOCATLLI et al ( JCO 1992 MAY ) .
100gms neosentalloy wire .
Markings
1. Distal wing of first pre molar bracket.
2. 5 to 7mm distal to the
anterior opening of the molar
tube.
3. Between the lateral
incisors and canines.

Crimp a stop to the wire at
each mark

Insert the wire into the
molar tube until the stop
abuts the tube



INITIAL

AFTER 4 MONTHS


NICKEL TITANIUM DOUBLE
LOOP SYSTEM
- GIANCOTTI
( JCO APRIL 1998 )
After second molar erupts
80g Neosentalloy arch wire
2 sectional arch wires


New application of superelastic NiTi rectangular wires
F.Miura, Mogi, Y.Okamoto ( JCO sept 1990 )
FINISHING WIRES
NEOSENTALLOY can be used in the initial phases
It has 3 dimensional tooth control.


FACTORS CONTROLLING FORCE LEVEL
HEAT TREATMENT – Changes force levels,and
memory properties
COMPOSITION OF THE ALLOY – Lowering the ratio
of the nickel decrease the force level


INDIVIDUALISED PRESURGICAL ARCH FORMS
- MIURA et al


Before surgery

After surgery


ADVANTAGES
Provides 3 dimensional control
Effective in surgical orthodontic cases
Eliminates need to change arch wires frequently
DISADVANTAGES
Bracket friction will be more when large wires are used


BIOEFFICIENT THERAPY
ANTHONY.D.VIAZIS ( JCO Sept 1995 )
Superelasticity –Llight constant force levels
Shape memory – Easy arch wire placement
REFRIGERENT SPRAY – ENDO ICE


SENTALLOY INTER ARCH COIL SPRINGS


WIRE SELECTION
Wire flexibility will be more
in vertical direction than
horizontal direction


ORIGINAL SUPERELASTIC WIRES ( ROUND
SENTALLOY )
Light, medium, & heavy force levels
RECTANGULAR NEOSENTALLOY
I generation:
1OOg, 200g, & 300g force levels
II generation:
80g force in the central incisor region(alignment)
320g force in the molar region (posterior leveling)


BIOFORCE IONGUARD WIRES
3-micron nitrogen coating that is produced by ion
bombardment of the wire surface.
Reduce 1.Friction
2. Breakage
3.Release of nickel into the mouth .


DIRECT ELECTIC RESISTANCE
HEAT TREATMENT METHOD
(DERHT)
ARCHMATE


DIRECT ELECTIC RESISTANCE
HEAT TREATMENT METHOD
(DERHT)


COPPER NiTi
VARIABLE TRANSFORMATION
TEMPERATURE ORTHODONTICS - ROHIT C. L.
SACHDEVA.
“Variable cross sectional orthodontics”.
“Variable modulus concept”
- BURSTONE

COPPER NiTi
“VARIABLE TRANSFORMATION
TEMPERATURE THERMO MECHANICS”
Stress induced martensite
Martensite transformation is also temperature
dependent


COPPER NiTi
AUSTENITIC FINISH TEMPERATURE ( Af )
should be lesser then body temperature.This
difference determines the force generated by nickel
titanium alloys.
Af can be controlled by affecting the composition ,
thermo mechanical treatment &manufacturing
process of the alloy.


COPPER NiTi
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

COPPER NiTi
QUATERNARY METAL – Nickel, Titanium, Copper,
Chromium
CLASSIFICATION
Type I
Type II
Type III
Type IV

Af – 150 c
Af - 270 c
Af - 350c
Af - 400c

COPPER NiTi
Type II wire
1. Generates the highest forces .
2. Average or higher pain threshold.
3. Normal periodontal health.
4. Rapid tooth movement is required.

COPPER NiTi
TYPE III WIRE
1. Low to normal pain threshold.
2. Slightly compromised periodontium.
3. When relatively low forces are desired.


COPPER NiTi III
CORRECTION AFTER WEEKS


COPPER NiTi IV
TYPE IV WIRE
1. Intermittent forces .
2. Patients who are sensitive to pain.
3. Compromised periodontal conditions.
4. Patients co operation is very less.
5. Beneficial as an initial rectangular wire


COPPER NiTi IV
CORRECTION AFTER 6 WEEKS


COPPER NiTi
OPTIMAL TOOTH MOVEMENT FORCE.
The ideal arch wire would not exhibit any hysteresis,
thus providing equal loading ( engaging ) &
unloading ( tooth driving forces ).
Copper enhances thermal reactive properties and
creates a consistent unloading force.


COPPER NiTi
Earlier shape memory wires have partially met these
goals.
eg : a partially corrected rotation .
A major cause of this deficiency is the hysteresis that
severly limits the working range of super elastic arch
wires.
Difficulty in setting constant TT while manufacturing .


COPPER NiTi
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.
3. Consistent TT has ensured consistency of force
from batch to batch of arch wires results in affective
tooth movement.

CHINESE NITI WIRE
CHINESE NiTi wire - A new orthodontic wire
- C. J. BURSTONE ( AJO JUNE 1985 )
Dr. TIEN HUA CHENG et al at the General
Research Institute for Non- Ferrous Metals in Beijing
China
( Late 1980s ).
Chinese NiTi wire has much lower transitional
temperature than NiTi wire.

CHINESE NITI WIRE
CANTILEVER APPARATUS
0.016 SS, Nitinol and A-NiTi
were submitted to a flexural
test


CHINESE NITI WIRE
3 Characteristics
1. The spring back.
2. Stiffness
3. Maximum movement.


CHINESE NITI WIRE
SPRING BACK
The range of action of the wire.
For 800 activation
SS – 160
Nitinol – 520
Chinese NiTi - 730


CHINESE NITI WIRE
STIFFNESS
The force or movement
produced for each unit
Activation


CHINESE NITI WIRE
The magnitude of force increases if the wire is retied
into a bracket.
1500
1000
500

0

20

40


60

80

CHINESE NITI WIRE
THE MAXIMUM MOVEMENT.
.
WIRE

MOVEMENT

SPRING
BACK

SS

%RECOVER
Y
20

3,067

16

NITINOL

2,112

52

65

NITI

1,233

73

91


CHINESE NITI WIRE
TEMPERATURE DEPENDENT CHANGES


CHINESE NITI WIRE
TIME DEPENDANT CHANGES.
The wires remained tied between 3 brackets for periods
of 1 minute,1 hour and 72 hours.


CHINESE NITI WIRE
CLINICAL SIGNIFICANCE
1. Applicable in situations where large deflections are
required.
2. When tooth are badly malpositoned.
. 3. Nitinol wire deformation is not time dependent
4.Middle range of deactivation forces are useful in
designing an appliance with constant forces.


Effects Of Cold Disinfectants On The Mechanical
Properties And The Surface Topography Of Nickel
Titanium Arch Wires.
- J.E.BUCKTHAL & R.P.KUSY ( AJODO
1988 )
1. High cost
2. Super elasticity
Heat sterilisation is the most reliable method of
destroying pathogens.

Nitinol is susceptible to a pitting type of
corrosion attack.
Sterilant solutions;
1. 2% acidic gluteraldehyde ( Banicide )
2. Chlorine dioxide ( Exspor 4:1:1 )
Disinfectant solution;
3. Iodophor ( Wescodyne )
Wires tested;
12 Straight 1 inch length of rectangular 0.017
X 0.025” Nitinol and Titanol

4 GROUPS;
0 ( Control )
1 ( Group 1 )
2 ( Group 2 )
3 ( Group 3 )
 BEND,
 TENSILE and
 LASER SPECTROSCOPY

SUMMERY
No significant changes were detected .
The results supported the use of cold disinfectant
procedures.


NICKEL HYPERSENSITIVITY REACTION
Strong biologic sensitizer
SYMPTOMS;
Contact dermatitis
contact stomatitis
Angular chelitis
Severe gingivitis
Mild erythema with or without edema

Nickel hyper sensitivity reaction before, during, and
after orthodontic therapy.
-G.R.P.JANSON et al ( AJODO JUNE 1998 )
.170 patients of both sexes were examined .
3 groups
A - Before
B - During
C - After
5% Nickel Sulfate in white petrolium

RESULTS
Orthodontic treatment with SS does not induce a
nickel hypersensitivity reaction.
Frequency in females is 4 times more than in males
Association between personal history of allergic
reaction & nickel hypersensitivity

BETA - TITANIUM
Beta titanium: A new orthodontic alloy
C.J.BURSTONE& A.J.GOLDBERG ( AJO Feb
1980)
ORMCO CORPORATION
3 characteristics
1. Spring back
2. Stiffness
3. Formability

- High
- Low
- High


BETA - TITANIUM
Beta titanium was introduced by Dr. CHARLES
BURSTONE and JON GOLDBERG in the university
of CONNECTICUT ( Early 1980s )
Composition
Titanium
- 73.5%
Molybdenum - 11.5%
Zirconium
- 6%
Tin
- 4.5 %

BETA - TITANIUM
At temperatures below 16250F – hexagonal
Closed packed crystal form.
Yield strength
- 55 X 103 p.s.i
Modulus of elasticity - 15.5 X 106 p.s.i
Spring back SS

YS = 0.35 X 10–2
E

- 1.1 X 10–2

BETA - TITANIUM
At temperatures above 16250 F pure titanium
rearranges into body centered cubic lattice
- BETA PHASE
BETA STABILISED ALLOYS ( molybdenum or
columbium )
Yield strength
– 1,70,000 p.s.i
Modulus of elasticity – 9,400.000 p.s.i
YS/E -1.8X10-2

BETA - TITANIUM
TEST FOR SPRING BACK
TINIUS OLSEN STIFFNESS TESTER
¼ inch span of wire
A. Straight wires
B. Wires with 350 bend
C. Wires which are over bent to 900 and then bent
back to 350


BETA - TITANIUM
MODE

STAINLESS
STEEL

BETA
TITANIUM

PERCENT
INCREASE

A

16.0

32.8

105%

B

16.5

31.3

90%

C

17.5

37.3

113%


BETA - TITANIUM
ADVANTAGES:







Low stiffness
Good formability
High spring back
Weldable
Ductile
Corrosion resistance


BETA - TITANIUM
Ideal edgewise arches can be deflected twice than SS
allows greater range of action and useful for
•
•

Initial tooth alignment
Finishing arches
Forces - 0.4% of SS
Eg;

0.018 x 0.025 TMA = 0.014 x 0.020 SS

BETA - TITANIUM
Highly ductile
Tieback loops
Complicated
bends


BETA - TITANIUM
LOOPS
‘ T’ Vertical
Helical
‘ L’ loop


BETA - TITANIUM
ROTATION

INTRUSION


BETA - TITANIUM


BETA - TITANIUM
Direct welding of auxillaries

Helical finger spring


BETA - TITANIUM
Welding of TMA wire
- C.J.BURSTONE ( JCO Sept 1987 )
5 basic principles;
1. Proper positioning
2. Minimum voltage
3. Small contact area
4. Single short pulse
5. Pressure


ROCKY MOUNTAIN DIAL-A-WELD
506A


1. POSITIONING
SET DOWN OF
80%

25 - 60 %


2. VOLTAGE

3. SMALLER CONTACT AREA
4. SINGLE PULSE
5. PRESSURE


Improper welding
Low voltage - The parts may delaminate
High voltage - Wire become brittle
Cracks
Melting


PASSIVE APPLICATIONS
ACTIVE APPLICATIONS

SPACE CLOSURE


To gain space in
The anterior
Segment


ROTATIONAL
CORRECTION


TO INCLUDE SECOND MOLARS


ALPHA TITANIUM
- WILCOCK company
TITANIUM - 90%
ALUMINIUM - 6%
VANADIUM – 4%
Close packed hexagonal lattice
ALPHA stabilising elements – Aluminum, Gallium,
Germanium, Carbon, Oxygen and Nitrogen
‘ NEAR ALPHA ALLOY ’

ALPHA – BETA PHASE


ALPHA TITANIUM
PROPERTIES;
Heat treated to improve strength
Satisfactory creep properties – Finishing & breaking
arches
wire becomes hard in the oral environment due to
hydrogen absorption
TITANIUM HYDRIDE
Less ductile – one slip plane
Nickel free

TITANIUM-NIOBIUM
A new finishing wire alloy
M. Dalstra et al ( COR 2000 July )
Nickel free Titanium alloy
(SYBRON DENTAL SPECIALITIES. CALIFORNIA )
Ti - 82%
Mo - 15%
Nb - 3%

( or)

Ti - 74%
Nb - 13%
Zr - 13%


TITANIUM-NIOBIUM
PROPERTIES







Easy to bend, fomability is less than TMA
When lower forces are used than TMA
Stiffness – ¾ of SS,
- ¼ of TMA
Load deflection rate is lower than TMA
Yield strength is lower than SS

TITANIUM-NIOBIUM
ADVANTAGES;




Substitute for SS
No leaching of nickel

CLINICAL IMPLICATIONS;

 Finishing wire with multiple bends
 Fixed retainers ( Biocompatible )

COMPOSITE WIRES
The future of orthodontic materials
ROBERT.P.KUSY (AJODO Jan 1998)
Metals
Polymers
Ceramics
Advantages are realised
Disadvantages are minimised


METALS
METALCERAMIC

CERAMICS

METALPOLYMER

SEMI
CONDUCTORS

CERAMICCOMPOSIRE

POLYMERS

COMPOSITE WIRES
In orthodontics
composite prototypes of arch wires, ligatures,
brackets - S-2 glass fibers ( ceramic )
- Acrylic resins ( polymer )
Esthetically pleasing because they tend to transmit
the colour of host teeth
Strong & Springy

COMPOSITE WIRES
PULTRUSION
The process of manufacturing components of
continuous lengths & a constant cross sectional
shape
Eg; Arch wires
Bundles of continuous fibers are impregnated with a
polymeric resin pulled through a sizing die
Then passed through a curing die that imparts a
precise shape ( Electro magnetic radiation )

COMPOSITE WIRES
The characteristics of the arch wires can be changed by
- PULTRUSION
Round
Rectangular
Ligature wires – Polyethylene fiber + Acrylic resin
2 ½ times stronger than SS
Lose most of their tying force in
less than 3 hrs

Comparison of unidirectional fiber reinforced polymeric
composites to NITI alloys in bending


COMPOSITE WIRES
ADVANTAGES;
patients with allergic reactions with nickel
Esthetic than previous wires
Better strength & springiness
DISADVANTAGES;
Shape can not be changed


COMPOSITE WIRES
OPTIFLEX WIRES
A composite ceramic fiber-plastic-nylon ( ORMCO )
Dr.TALASS


COMPOSITE WIRES
Structure – Clear optical fiber made of 3 Layers
A. Silicon dioxide core
- Force
B. Silicon resin middle
layer
- Protection from
moisture
C. Nylon layer
- Prevents from
damage

COMPOSITE WIRES
The wire can be ROUND or RECTANGULAR

•
•
•
•

Wide range of action
Light continuous force
Sharp bend must be avoided
Highly resilient - Effective in the alignment of
crowded teeth


TIMOLIUM WIRES
Improved titanium wires
1. FRICTION
2. RESISTANCE TO BREAKAGE
1. FRICTION
Smooth surface texture
Less friction
Accelerate treatment time

TIMOLIUM WIRES
2. RESISTANCE TO BREAKAGE


Surface defects



Yield strength



Compressive strength


BETA –III WIRES
Introduced by RAVINDRA NANDA

Bendable

High force

Low deflection rate

Co-efficient of friction is more

Nickel free titanium wire with memory

Ideal for multilooping, cantilever, utility arches
First choice of wire for finishing stages where tip
& torque corrections fully accomplished during initial
stages.

NICKEL TITANIUM PALATAL
EXPANDER
CORRECTION OF POSTERIOR CROSS BITES
- Skeletal expansion
- Dental expansion
The goal of palatal expansion is to maximise skeletal
movement and minimise dental movement.
EXPANSION APPLIANCES
- Rapid palatal expansion appliances
- Slow expansion appliances

EXPANDER
RAPID PALATAL EXPANSION APPLIANCES
( RPE)
- Produce large forces at the suture site
over
a short period.
Conventional RPE appliances
1. Uncomfortable
2. Require patient co- operation
3. Laborious
4. Inefficient because of the intermittent nature
of their force application

EXPANDER
Slow expansion appliances
- Light , continuous forces
- Best physiologic changes ( Both orthopedic and
orthodontic )
- Produce a widening rather than an actual
separation of the suture.


EXPANDER
NICKEL TITANIUM PALATAL EXPANDER
W.V.ARNDT ( JCO 1993 )
Tandem loop, nickel titanium ,
temperature activated palatal expander.
- Light continuous pressure on the mid
palatal suture .
( Simultaneous uprighting , rotating , and distalising
the maxillary first molars )

EXPANDER


EXPANDER
THE ACTION OF THE APPLIANCE
- A consequence of nickel titanium’ s shape memory
and transition temperature effects.
The nickel titanium expander has a transition
temperature of 940 F.



Below TTR – Metal is flexible
Above TTR – Metal stiffen

BELOW 20 0 C


AT

TTR







8 Different intermolar widths
( 26mm – 47mm )
Forces ranging from 180 – 300gms
26 – 32mm - Softer wires that produce lower force
levels for younger patients
3mm will be added for overcorrection

Passive
appliance

Initial
activation


After
expansion

“ COMPLETE
MAXILLARY
RIGHT
CROSSBITE”


A comparison of dental and dentoalveolar changes
between rapid palatal expansion and nickel titanium
expansion appliances.
- C. CIAMBOTTI et al ( AJODO JAN 2001 )
The objectives;
To compare – Amount of mid palatal suture separation
- Alveolar process tipping
- Maxillary first molar tipping
- Maxillary first molar rotation
- Palatal depth changes

Mixed or early permanent dentition.
12 patients treated with RPE appliances ( 6 males, 6
females with an average age of 11.1 yrs )
Duration 127 days
13 patients treated with NiTi palatal expansion
appliances. ( 3 males, 10 females with an average of
9.4 yrs )
Duration 153 days

RPE APPLIANCE – A tooth borne appliance
Mid palatal jack screw
Activation 0.5mm, 2 times per day
Expansion – Occlusal aspect of lingual cusp of
maxillary first molar contacted the occlusal aspect of
buccal cusp of mandibular first molar.

NiTi EXPANDER
A tandem loop temperature activated appliance ( GAC
International ) designed by ARNDT
The proper size was selected by measuring the inter
molar width and then adding 3 to 4mm
Tetrafluoroethane refrigerant

NiTi expander

RME


RESULTS
1. Palatal width change
- RPE group is 28 %
- In NiTi group 16 %.
2. Buccal tipping of the alveolar
process
- RPE group – 5.080.
- NiTi group – 6.610
3. Molar rotation
- RPE group 1.580
- NiTi group 26.610

4. Radiographic evidence shows that mid palatal
suture separation is less obvious in the NiTi group
than RPE group.
5. No correlation between age and amount of dentoalveolar expansion.
6. RPE appliance widened the palate more reliably,
NiTi appliance tipped the molars buccally.


A review of contemporary arch wires: Their
properties and characteristics
- ROBERT KUSY ( AO JUNE 1997 )
CHARACTERSTICS OF THE IDEAL ARCH WIRE
Ideally archwires are designed to move teeth with
light continuous forces
No one wire is best for all stages

Strong

Good range
Esthetic

Resilient
Biocompatible

Formable

CRITERIA OF AN
IDEAL ARCH WIRE

Weldable

Tough
Poor
Biohost
Good
Spring back
Low
friction

Springy

APPLYING ARCH WIRES
During initial stages
- great range and light forces
VARIABLE CROSS SECTION ORTHODONTICS
- Multistranded stainless steel wire
Variable modulus orthodontics
- NiTi alloy wire

Intermediate stages of treatment



Beta titanium alloys
Larger sizes of Nitinol
( under sized stainless steel wire if sliding
mechanics are required )


FINAL STAGES OF TREATMENT
More arch stability and less tooth movements
- Large gauges of beta titanium or
- Stainless steel wires


A comparative study of metallurgical and working
properties of two new titanium based alloy wires
(TiMolium and Beta III ) with the earlier introduced
titanium wires ( TMA ), and also alpha titanium wires
- Jiku Abraham
TiMolium
– T.P.Orthodontics
Beta III
- Ortho organizers
TMA
- Ormco corp.
Alpha Titanium – A.J. WILLCOCK


Straight rectangular wires
GROUP I
4 wires in 16”x 22” dimension
GROUP II
GROUP III


1.
2.
3.
4.
5.
6.
7.
8.
9.

Properties studied are
Yield, tensile strength & elastic modulus
Maximum load via 3-point bending test
Frictional resistance
Welding characteristics
Stress relaxation
Working range / spring back
Surface topography
Micro hardness
Elemental analysis

INSTRON MODEL NO.1193

Expr. Setup for
Yield strength &
ultimate tensile strength


Manufacturers claim that;




TiMolium is superior to TMA wires in the following;
1. Friction and surface smoothness
2. Compressive strength
3. Yield strength & breakage resistance
Beta III is bendable , high force low deflection,
nickel free arch wire with memory.


Results of the study showed that

The coefficient of friction, surface smoothness,yield
strength & ultimate tensile strength of TiMolium was
superior to that of TMA .
However TMA has low load deflection rate and high
spring back than TiMolium .

Yield strength of Beta III was lower than TMA and
TiMolium

Formability is good but resiliency is low.


CLINICAL IMPLICATIONS OF THIS STUDY;
1. Correction of crowding or alignment of teeth TMA > Beta III
2. Intrusion TMA shows a better stress relaxation
TMA > TiMolium .

3. Space closure




Sliding mechanics TiMolium shows lowest values of coefficient of
friction in both static as well as kinetic friction.
TiMolium > Alpha titanium
Frictionless mechanics –
Formability - Beta III > TMA > TiMolium
Resilience - TiMolium > TMA > Beta III

WELDABILITY
TiMolium > Beta III
FINISHING STAGES
Incomplete tip, torque correction
Beta III > TMA > TiMolium


Thank you
For more details please visit

Nickel titanium alloys /certified fixed orthodontic courses by Indian dental academy

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