Nickel Titanium Alloys / orthodontic courses by Indian dental academy

NICKEL-TITANIUM NICKEL-TITANIUM ALLOYSALLOYS

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NEWER ORTHODONTIC NEWER ORTHODONTIC WIRESWIRES INDIAN DENTAL INDIAN DENTAL ACADEMYACADEMY Leader in continuing dental education www.indiandentalacademy.comwww.indiandentalacademy.co

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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”www.indiandentalacademy.co

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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)


PROPERTY AUSTENITE AUSTENITE

YIELD STRENGTH 560 MPa 100 MPa

ELASTIC MODULUS

75 GPa 28 GPa

NICKEL-TITANIUM


NICKEL-TITANIUM Martensitic transformation of NiTi

FIDUCIARY LINE


MARTENSITIC TRANSFORMATIONADDDITIONS 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


NICKEL-TITANIUM ALLOYS The crystal structure of the alloy will be

confirmed by means of RADIOGRAPHIC DEFRACTION or DIFFERENCIAL SCANNING CALORIMETRY

STUDY OF RESISTIVITY


NICKEL-TITANIUM ALLOYS RESISTIVITY


NICKEL-TITANIUM ALLOYS 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.


NICKEL-TITANIUM ALLOYS THERMOELASTICITYThrough 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


NICKEL-TITANIUM ALLOYS 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

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NICKEL-TITANIUM ALLOYS 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.


NICKEL-TITANIUM ALLOYS 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


NICKEL-TITANIUM ALLOYS 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


NICKEL-TITANIUM ALLOYS LOAD- DEFLECTION CURVE


NICKEL-TITANIUM ALLOYS 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.


NICKEL-TITANIUM ALLOYS CLASSIFICATION

NiTi orthodontic wires are generally classified as

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


NICKEL-TITANIUM ALLOYS 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.


NICKEL-TITANIUM ALLOYS III) EVANS and DURNING introduced a even more

comprehensive classification of orthodontic alloys dividing into 5 groups.

1) Phase 1 – Including alloys like gold and ss. 2) Phase II – Stabilised 3) Phase III – Super elastic active austhentic 4) Phase IV – Thermodynamic active

martensitic 5) Phase 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 ). www.indiandentalacademy.co

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NITINOL Ni – Nickel Ti – Titanium Nol - 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.


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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 250,000p.s.i

280,000 to 300,000p.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


NITINOLCLINICAL 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


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. www.indiandentalacademy.co

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JAPANESE NITI 1. Tensile test

Tensile testing was performedfirst 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.


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CLINICAL IMPLICATIONS0.016” medium preformed arch wire was tied

into thelateral incisor and canine bracket.

INITIAL

TWO MONTHS LATER


CLINICAL IMPLICATIONS 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.


CLINICAL IMPLICATIONS 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.


CLINICAL IMPLICATIONS FACTORS THAT AFFECT THE MECHANICAL

PROPERTIES OF SPRINGS.

1. Diameter of the wires super elastic activity. 2. Size of the lumen 1/ super elastic activity. 3. Martensite transformation temperature 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.


CLINICAL IMPLICATIONS Closed coil spring

After 5 months


CLINICAL IMPLICATIONS

Open coil spring

After 3 months


CLINICAL IMPLICATIONS 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.


CLINICAL IMPLICATIONS 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


CLINICAL IMPLICATIONS NICKEL TITANIUM DOUBLE LOOP SYSTEM - GIANCOTTI ( JCO APRIL 1998 )

After second molar erupts 80g Neosentalloy arch wire 2 sectional arch wires


CLINICAL IMPLICATIONSNew 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.


CLINICAL IMPLICATIONSFACTORS 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


CLINICAL IMPLICATIONS INDIVIDUALISED PRESURGICAL ARCH FORMS - MIURA et al






CLINICAL IMPLICATIONS Before surgery After surgery


CLINICAL IMPLICATIONS 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





CLINICAL IMPLICATIONSSENTALLOY INTER ARCH COIL SPRINGS


CLINICAL IMPLICATIONSWIRE SELECTION Wire flexibility will be more in vertical direction than horizontal direction


CLINICAL IMPLICATIONS 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)


CLINICAL IMPLICATIONS 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)


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 Af – 150 c Type II Af - 270 c Type III Af - 350c Type IV 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.www.indiandentalacademy.co

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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


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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-NiTiwere submitted to a flexuraltest


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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


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CHINESE NITI WIRE STIFFNESS

The force or movementproduced 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 80www.indiandentalacademy.com

CHINESE NITI WIRE THE MAXIMUM MOVEMENT..

WIRE MOVEMENT SPRING BACK

%RECOVERY

SS 3,067 16 20

NITINOL 2,112 52 65

NITI 1,233 73 91


CHINESE NITI WIRETEMPERATURE 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 - TITANIUMBeta titanium: A new orthodontic alloy C.J.BURSTONE& A.J.GOLDBERG ( AJO Feb

1980) ORMCO CORPORATION 3 characteristics 1. Spring back - High 2. Stiffness - Low 3. Formability - High www.indiandentalacademy.co

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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 –

hexagonalClosed packed crystal form.

Yield strength - 55 X 103 p.s.i Modulus of elasticity - 15.5 X 106 p.s.i Spring back - YS = 0.35 X 10–2

E SS - 1.1 X 10–2


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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 - TITANIUMTEST 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 CLINICAL IMPLICATIONS

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 SSwww.indiandentalacademy.com

BETA - TITANIUM CLINICAL IMPLICATIONS 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 - TITANIUMWelding 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


CLINICAL IMPLICATIONSPASSIVE APPLICATIONS

ACTIVE APPLICATIONS

SPACE CLOSURE



To gain space in The anterior Segment



ROTATIONAL CORRECTION


CLINICAL IMPLICATIONSTO 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 ’www.indiandentalacademy.co

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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% Ti - 74% Mo - 15% ( or) Nb - 13% Nb - 3% 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 WIRESThe future of orthodontic materials ROBERT.P.KUSY (AJODO Jan

1998) Metals Polymers Ceramics Advantages are realised Disadvantages are minimised


METAL-CERAMIC METAL-

POLYMER

CERAMIC- COMPOSIRE

POLYMERS

METALS

CERAMICS

SEMICONDUCTORS


COMPOSITE WIRESIn 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 ) www.indiandentalacademy.co

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COMPOSITE WIRESThe 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 hrswww.indiandentalacademy.co

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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 www.indiandentalacademy.co

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COMPOSITE WIRESOPTIFLEX WIRES A composite ceramic fiber-plastic-nylon

( ORMCO )

Dr.TALASS


COMPOSITE WIRES Structure – Clear optical fiber made of 3 Layers

A. Silicon dioxide core - ForceB. Silicon resin middle layer - Protection from moistureC. Nylon layer - Prevents from damage www.indiandentalacademy.co

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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


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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.www.indiandentalacademy.co

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NICKEL TITANIUM PALATAL EXPANDERCORRECTION 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


NICKEL TITANIUM PALATAL EXPANDERRAPID 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


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NICKEL TITANIUM PALATAL 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.


NICKEL TITANIUM PALATAL 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 ) www.indiandentalacademy.co

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NICKEL TITANIUM PALATAL EXPANDER


NICKEL TITANIUM PALATAL 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 200 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


Passiveappliance

Initial activation

After expansion


“ COMPLETE MAXILLARY RIGHT CROSSBITE”


A comparison of dental and dento- alveolar 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 www.indiandentalacademy.co

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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 dento- alveolar 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


CRITERIA OF ANIDEAL ARCH WIRE

Esthetic

Good range

PoorBiohost

Tough

GoodSpring back

Lowfriction

Weldable

Springy

Formable

Biocompatible

Resilient

Strong


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” dimensionGROUP II 4 wires in 17”x 25” dimensionGROUP III 4 wires in 19”x 25” dimension


Properties studied are 1. Yield, tensile strength & elastic modulus2. Maximum load via 3-point bending test3. Frictional resistance4. Welding characteristics 5. Stress relaxation6. Working range / spring back7. Surface topography8. Micro hardness9. 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.


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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. www.indiandentalacademy.co

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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 www.indiandentalacademy.com

Documents

Nickel Titanium Alloys / orthodontic courses by Indian dental academy