Materials in orthodontics /certified fixed orthodontic courses by Indian dental academy

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

IMPRESSION MATERIALS
ACRYLIC MATREIAL –REMOVABLE PLATE
BANDS
BRACKETS
CEMENTS
ARCH WIRES
BONDING MATERIALS
ELASTICS
MAGNETS IN ORTHODONTICS

IMPRESSION MATERIAL
ALGINATE
composition
type- fast & slow setting
properties

BAND MATERIAL
STAINLESS STEEL
PREFORMED
FABRICATE
Different sizes
Preformed – according to diff. manufactures
Fabricate- band material -150X0.005”
180x 0.005”www.indiandentalacademy.com

S S BANDS
Preformed

BRACKETS
GOLD
STAINLESS STEEL
CERAMIC(TOOTH COLOURED)
TITANIUM

STAINLESS STEEL BRACKET
Pre-adjusted edgewise bracketwww.indiandentalacademy.com

Beggs bracket – vertical slot

Nickel sensitivity – titanium as an
alternative to SS bracket
Cutaneous sensitization to nickel develop
from skin contact with any jewelry
Most common in females

CERAMIC BRACKET

Introduced in late 1980s
Advantage – tooth colored
Disadvantage –
1. Staining and discoloration in patient
who smoke & drink coffee more
2 .Poor dimensional stability
3 .Friction b/n plastic bracket and arch
wire

CEMENTS
Cementing orthodontic bands
ZINC PHOSPHATE
GIC(LUTING)
MODIFIED GIC-LIGHT CURE

GIC

For a patient visiting to orthodontists
The only Medicine Will Be
Forcewww.indiandentalacademy.com

WIRES
Composition
Manufacturing & Heat Treatment
Properties

ARCH WIRES
CLASSIFICATION
1] According to the material used :
S.S
Elgiloy
Niti
TMA
2] According to shape
Round: 0.014 , 0.016 , 0.018 etc
Rectangular : 0.016x0.16 ;0.016 x0.022 ;
0.017x0.025
3] According to the properties of springiness :
Elastic / Springy
Intermediate
Rigid www.indiandentalacademy.com

BASIC PROPERTIES OF ELASTIC
MATERIAL
STRESS – is internal distribution of load
defined as force per unit area.
STRAIN – is internal distortion produced
by load defined as deflection per unit
length.

Orthodontic arch wires are like elastic material
which shows typical force
deflection curve
Point of arbitrary clinical
loading
stiffness
Range

Orthodontic material properties
STRENGTH
STIFFNESS
RANGE

STRENGTH
It is a force value that is a
measure of the maximum possible
load i.e., the greatest force that a
wire can sustain or deliver, if it is
loaded to the limit of the material.
Strength measured in stress units i.e
gm/cm2

STIFFNESS
It is the rate of force delivery
required for a unit activation .
It is the measure of the force
required to bend or otherwise
deform the material to a definite
distance.

RANGE
Range is defined as the distance
that the wire will bend elastically
before permanent deformation
occurs.
Range is usually determined from
the 0.1% offset point on the force
– deflection diagram.

Strength,Stiffness and Range have an
important relationship,i.e.,
Strength = Stiffness x Range

Resilience –represents the energy
storage capacity of the wire
Formability- amount of permanent
deformation that wire sustain before
failing

IDEAL WIRE MATERIAL FOR
ORTHODONTIC PURPOSE
IT SHOULD POSSESS
High Strength
Low Stiffness
High Range
High Formability

The material should be
Weldable or Solderable
Low cost

ORTHODONTIC ARCH WIRE
MATERIAL
PRECIOUS METAL ALLOYS
STAINLESS STEEL
COBALT-CHROMIUM ALLOYS(ELGILOY)
NICKEL-TITANIUM (NiTi) ALLOYS
BETA TITANIUM( TMA)
COMPOSITE PLASTIC
TOOTH COLORED WIRES

PRECIOUS METAL ALLOYS
Use routinely before 1950s
Gold , platinum, palladium etc

GOLD ALLOY WIRES
The first wire introduced for orthodontic
purpose was made of gold
Gold arch wires were the ideal choice of
arch wires with good bio-compatibility.

Composition of many gold alloy wires
corresponds to the type IV gold
casting alloys
They are also subjected to softening
and hardening heat treatments.
Crozat appliance was orignally made
from gold in 1900s

STAINLESS STEEL ALLOY
Stainless steel wires began to
replace gold wires in the 1930’s .
Steels are iron – based alloys that
usually contain less than 1.2%
carbon.

Silicon,phosphorous,sulphur,
manganese, tantalum, and niobium
may also be present in small
amounts. The balance is iron.
These alloys are often designated as
American Iron and Steel
Institute(AISI) Series 400 stainless
steels.

When 12-30% chromium is added
to steel the alloy is commonly
called STAINLESS STEEL.
For orthodontic purpose 18:8
stainless steel is used
( 18% chromium and 8% nickel)

S S replaces Gold wire because of
its better strength and springiness
Properties of steel wires controlled
by amount of cold working and
annealing
Steel is soften- by annealing
Harden –by cold working
Fully annealed wire – making
ligature wire. (dead soft wire)

Ligature wire

AUSTRALIAN ORTHODONTIC
ARCHWIRE –stainless steel
A. J. Wilcock of Victoria, Australia,
produced the orthodontic archwire to
meet Dr. Begg’s needs for use in Begg
technique.
The wire produced has certain unique
characteristics different from usual
stainless steel wires

Grading and colour coding of
Australian Orthodontic Arch
wires
REGULAR GRADE : White label
REGULAR PLUS GRADE : Green Label
SPECIAL GRADE : Black Label
SPECIAL PLUS GRADE : Orange Label

Each grade of wire is available in
diameters of 0.010″, 0.012″, 0.014″,
0.016″, 0.018″, 0.020″, 0.022″. They
are supplied in the form of spools or
cut lengths of the wire.

CLINICAL USE OF STAINLESS
STEEL WIRE
Orthodontic stainless steel is the most
widely used alloy in orthodontics.
Its application as
Arch wires
Auxillaries -springs
Retainers
Removable appliances
Bands etc.

The wires are available both in round
as well as rectangular cross-sections.
The Australian stainless steel wires
described previously are used in the
Begg’s technique as well as in the
preadjusted edgewise technique

MULTISTRANDED
WIRES
Twist flex- UNITEK
Force 9 - ORMCO
D-rect – ORMCO
Respond – ORMCO

Nickel Titanium Wires
(NiTi)
William F. Buehler in 1960’s
invented Nitinol
NOL (Naval Orddnance Laboratory)
Ni – Nickel
ti-titanium

Andreasen G.F. and co-
workers introduced the use of
nickel-titanium alloys for
orthodontic use in the 1970’s.

COMPOSITION
55% nickel
45% titanium
1.6% cobalt also is added to obtain
desirable properties.

NiTi can exists in more than one form or
crystal structure.
MARTENSITIC FORM – exists at lower
temperature
AUSTENTIC FORM - at higher
temperature

PROPERTIES
Shape Memory
Super elasticity
Both of these properties occur at
low transition temperature b/n the
martensitic and austenitic forms.

Shape memory - This indicates that a
material will return to its desired shape
after being plastically deformed while in
martensitic form.

THERMOELASTICITY
When alloy is cooled below transition
temperature it deforms plastically, but
when it is heated again the original
shape is restored----this property called
thermoelasticity.

Thermodynamic –refers to the ability
of an archwire to return to its
intended shape once heated through
its transition temperature. To be of
clinical value, thermodynamic
archwires must have a transition
range close to mouth temperature.

Andreasen introduced 0.019 inch
thermal nitinol wire with a
transition temperature range
between 31° C and 45° C.

Martensitic NiTi first marketed by
Rocky Mountain & is now
commercially available as M NiTi
In later 1980s NiTi wires with an
active austenitic grain structures (A
NiTi) appeared- with property of
superelasticity

Super elasticity – This property
can be produced by stress and
not temperature difference.
Therefore it is called as
stress induced martensitic
transformation

A NiTi – force applied is not the same
as force applied to activate it. i.e
means unloading curve differs from
its loading curve
E.g Copper NiTi

Type I
Type II
Type III
Type IV
advantage of cu- NiTi
produced light continuous forces for long
duration.
Cu NiTi (copper NiTi)

TYPE I wire –Af 150
generate very high forces
TYPE II wire- A f270
generate highest force among all
Uses-
in pt with higher pain threshold
normal periodontal health
rapid tooth movement is required

Type III Wire- Af 350
generate midrange force
normal pain threshold patient
generate light force
use in normal or slightly compromised
periodontal patient

PROPERTIES OF COPPER
NiTi WIRES
1. Copper Ni Ti generates a more
constant force over long
activation spans than other
nickel titanium alloys and does
so on a consistent basis, from
archwire to archwire.

For every small activations,
Copper NiTi generates near
constant force, unlike other
nickel titanium alloys.
Copper NiTi is more resistant to
permanent deformation
compared with other nickel
titanium alloys; it exhibits
better spring back
characteristics.

Type IV – Af 400
generate tooth driving force
forces are intermittent
use in pt who are sensitive to pain
periodontal compromised cases

Another wire called the Japanese
Niti wire introduced by Fujio
Miura is manufactured by a
different process and
demonstrates super elasticity.

Another nickel titanium alloy
introduced by Burstone
developed by Dr Tien Hua
Cheng called as Chinese Niti
alloy exhibits superior spring
back property when compared
to Nitinol

Due to little work hardening and
presence of the parent phase
which is austenite yielding better
mechanical properties.

CLINICAL USE OF NICKEL
TITANIUM WIRES
Nickel titanium wire can produce
an uniform constant force which
is delivered for a long period of
time during the de-activation of
the wire.

Because of its superior spring
back, superelasticity, shape
memory, and its ability to
produce light force for longer
duration , NiTi is
 ideal wire for initial levelling
and aligning.


BEFORE
AFTER ALIGNMENT

 Rectangular NiTi allows full
engagement of the bracket slot
and give better torque control in
the initial phase of treatment.
Recently a NiTi palatal expander

NiTi is also available in the form
of coil springs.
Used for distalisation of molars.

Reverse curve NiTi, also known
as Rocking chair NiTi helps in
bite opening and when placed
down helps in bite closure along
with levelling and aligning.

Cobalt Chrome alloy (Elgiloy)
Developed during the 1950’s by the
Elgiloy Corporation(Elgin, IL,USA).
Manufactured for watch springs by
Elgin watch company, hence the
name Elgiloy.

COMPOSITION
40% cobalt,
20% chromium,
15% nickel,
7% Molybdenum,
2% manganese, 0.16% carbon, 0.04%
beryllium and 15.8% iron.

Supplied in softer form and harden by
heat treatment
Heat treatment – increases the
strength

TYPES OF CHROME
COBALT ALLOY WIRES
Blue(soft) elgiloy :
bent easily with finger pressure
pliers.
Heat treatment of blue elgiloy
increases its resistance to
deformation.

Yellow elgiloy :
Relatively ductile and more
resilient than blue elgiloy.
Further increase in its resilience
and spring performance can be
achieved by heat

Green elgiloy : More resilient than
yellow elgiloy and can be shaped
with pliers before heat treatment.
Red elgiloy :
Most resilient of elgiloy wires, with
high spring qualities,
. Heat treatment makes it extremely
resilient.

β – TITANIUM – TITANIUM
MOLYBDENUM ALLOY OR
T.M.A.
high temperature” form of
titanium alloy became available.
At temperature above 1625°F
pure titanium rearranges into a
body centered cubic lattice
(B.C.C.), referred to as ‘Beta’
phase.

Addition of elements as
molybdenum or columbium,
a titanium based alloy can
maintain its beta structure
even when cooled to room
temperature. Such alloys are
referred as beta stabilized
titanium.

High temp Ti – Beta phase
Molybdenum + Ti –TMA
i.e in low temp maintain beta
phase

PROPERTIES TMA
Excellent formability]
Reduced load/deflection
Excellent resiliency

Elastics
Made up of latex
Separator
E chain
module

CLINICAL USE
choice for utility arches.-
INTRUSION

TOOTH COLOURED
ORTHODONTIC WIRES
current generation are built of
composite plastics,
Optiflex WIRE
Made of clear optical fibre, it
comprises of three layers.
CV NiTi WIRES

Indirect bonding

Indirect bonding
SILVERMAN AND COHEN – 1972
MMA and UV light activated unfilled
BISGMA
MMA was applied to the plastic bracket
base on the patient’s model
BISGMA –intermediary adhesive
between the patients etched enamel &
pre set adhesive on the bracket base

Indirect bonding
Updated technique – 1974 by same
authors
Used perforated metal bracket bases and
only one adhesive- BISGMA[ UV light
activated]
Increased operator working time as
polymerization did not occur

INDIRECT BONDING
ADVANTAGES
Accurate bracket placement
Decreasing the chair side time
Avoiding band fitting on the posterior teeth
Eliminating the need for separators
Improved ability to bond the posteriors
Improved patient comfort and hygiene

INDIRECT BONDING
Disadvantages
Technique sensitive
Additional set of impressions need to be
taken
Posterior attachments more likely to fail if
the patient chews on hard food

Indirect bonding techniques
Thomas technique
Silicon transfer tray
Double sealant technique
Moin & Dogon technique
Indirect method – Anoop Sondhi
Indirect bonding for light cured composites

Indirect bonding
Moin & Dogon technique AJO 1977
Pour impression in
stone
A drop of sticky wax
is placed on teeth
surfaces of cast
Brackets are
warmed over flame
and set on the cast

Indirect bonding - Moin & Dogon technique
Impression made with
polyether material
Tray separated from
cast but brackets remain
in situ
Bracket is removed from
the cast &warmed to
remove residual wax
They are placed into the
impression

Teeth are pumiced,etched & isolated
Enamel surface is sealed with mixture
of universal & catalyst sealant
bracket base is covered with the
adhesive
tray is seated

Use of sticky wax-corrections can
easily &readily be made until optimal
bracket alignment is obtained
Previously used
Adhesive tape - bracket displacement
Bonding resin – cleaning of bracket
base prior to bonding difficult and time
consuming

Indirect bonding – ANOOP SONDHI
AJO 1999
NEW INDIRECT BONDING MATERIAL
3 M UNITEK / SONDHI RAPID SET
Unique features
Increased viscosity - silica fillers[5%]
Quick set time – 30 secs
Decreases the time needed for holding the
bonding tray
Completely cured 2 min allowing rapid
removal of the tray

Alginate impressions
made
working models poured
in stone

APC brackets used
and positioned over
the teeth excess
adhesive removed

Bracket positions
checked
Models are placed
in the TRIAD
curing unit 10
minutes

Indirect bonding – ANOOP
SONDHI
Block the
undercuts
Construct tray with
bioplast material
[1mm] thick
overlayered with
bioacryl

SONDHI
Excess tray
material is trimmed
off with scalpel
Trays placed in the
TRIAD unit to
ensure that
uncured resin is
cured

SONDHI
Prepare patient
Pumice , Etch &
isolate
Tray can be
sectioned if there
is severe
crowding

Small amounts of
resin A and B are
poured into the
wells
Resin A – tooth
surface
Resin B – resin
pads in the tray

Seat the tray over
the teeth
Hold with uniform
pressure for 30
seconds
Leave the tray on
for another 2
minutes to ensure
complete
polymerization

not really a bracket
placement device
Rather it orients the
arch wire slot of the
bracket relative to the
facial surface
Accomplished by
holding the archwire
slot stationary while
manipulating each
tooth to any tip angle ,
torque, rotation &
height .
The slot machine & indirect bonding

[ Orientation templates & rotation
guides]

SEALING
Sealer / Primer / Intermediate resin
Low viscosity resin which is applied
prior to bonding .
 Necessary to achieve proper bond
strength
 Improve resistance to microleakage
 Both reasons
 Not needed at all

Chemically cured
Sealant
Light cured
Ceen & Gwinnett
Found
Light cured sealant Chemically
cured
Protect enamel Polymerize poorly
adjacent to bracket Have low
resistance from discoloration towww.indiandentalacademy.com

Evaluation of sealant in
orthodontic bonding
Wei Nanwang etal AJO 1991
Evaluated the Tensile bond strength with
and without use of sealant
They found no statistically significant
difference in the bond strength of the two
evaluated groups

However the use of sealant
May offer extra protection to enamel
during debonding
As chances of enamel surface
detachment with out use sealant was
greater.

Self Etch Primer
Unique characteristic of some bonding
system is that they combine the
Etchant + Primer into single product
Saves time
Cost efficient

Self Etch Primer
Prompt L Pop
Transbond self etch primer
Liquid begins to etch as soon as it is
applied www.indiandentalacademy.com

Etchant Primer
When two hydroxide
ions are converted
hydrogen ions are
released

Procedure For Self Etch
Teeth are pumiced
Self etch primer gently swirled on to each
enamel surface for 2 to 5 secs
As pH rises , etchant is converted to
primer
Primer is thinned with burst of air
No rinsing with water
Bracket then bonded in usual way.

Conclusion-
No significant difference in bond strength
between the two groups.
10 min delay in bonding after application
of self etch primer might not be deleterious
for adhesion

Hydrophilic Primer ( MIP )
Bond failure – Moisture contamination
When etched enamel is wet most
porosities get plugged – Penetration of
resin impaired
Second molars – Access difficult
Hydrophilic primer (HEMA & Maleic acid)
dissolved in acetone – 3M Unitek
( Transbond MIP )

Thank you
For more details please visit

Materials in orthodontics /certified fixed orthodontic courses by Indian dental academy

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Materials in orthodontics /certified fixed orthodontic courses by Indian dental academy

Similar to Materials in orthodontics /certified fixed orthodontic courses by Indian dental academy (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Materials in orthodontics /certified fixed orthodontic courses by Indian dental academy