Dr.amit tooth coloured-presentation

INTRODUCTION
Orthodontics needs a variety of devices, made from a
large array of materials, which should be harmless.
According to paracelsus in 16th
century a physician “All
substances are poisons. There is none, which is not a poison.
The right dose differentiates the poison from remedy”.
Newer materials such as composites present new
challenges because of the potential for interaction. Although
so some extent the problems raised by orthodontic materials
are the same as those raised by dental materials in general,
the former deserve a more specific and differentiated
approach. Specialization has created a gap between the
materials used by orthodontics and those used by dentists.
Few branches of medicine match orthodontics in its
dependence on materials and concomitant rapid assimilation
of new products.

GENERAL REQUIREMENT FOR BIO MATERIALS
It should be :
Non-toxicity
Strength
Hydrolytic stability
High purity
Reproducible quality
Sterilizability

EVOLUTION OF ORTHODONTIC BIO MATERIALS
Material Scarcity(1750 - 1930)
At the 19th
century E.H. Angle launched a list of few
materials appropriate for orthodontic work, basic design for
most of the orthodontic appliance stemmed from that period,
these include strips or wires of precious metal, wood, rubber,
vulcanite, piano wire and silk thread. Half a century later, it
was focused on molar band versus screw band, German
silver arches versus gold arches and different types of band
materials and ligatures.
(1930 - 1975)
Major developments in metallurgy and analytic and
organic chemistry as well as improvement in metal treatment
and emergence of new plastic, gave rise to first mass
production orthodontic device in the 1960s.

1975 to the present
Over the past 25 years the number of orthodontic
manufacturers has grown both in quantity and variety of the
products. Manual and analog machines have been replaced
by digitally controlled molds, increasing both production
and quality. Computer Aided Design (CAD) and Computer
Numerically Controlled (CNC). Machines now allow large
production, to the traditional materials (i.e. metals, plastics)
manufactures have added ceramic and composite device.

In fixed orthodontic appliance system, consist of
active and passive component like bands, brackets, arch
wires tubes and other accessories like ligature, springs,
elastomeric chains.
One of the requirement from the patient view is
esthetics or invisible orthodontics. Hence, various brackets
and arch wire have been introduced into the market.

TOOTH COLOURED BIO MATERIALS USED IN
ORTHODONTICS ARE :
I. Brackets
• Plastics - reinforced type (glass, ceramic, metal)
• Composite - Ceramic - Polymer
- Metal - Polymer
- Ceramic filler, plastic body, metal liner.
Ceramic
II. Arch wires
• Composite arch wires (optiflex)
• Teflon coated arch wires
• Plastic coated arch wires

III. Ligature wire
• Composite coated
• Teflon coated
IV. Retainers
Essix Appliance
V. Invisalign System

POLYMERS
Organic polymers are natural allies of medicine
because they enter the composition of living tissues.
IDEAL REQUIREMENT FOR ORGANIC POLYMERS
Non-degradable
Stable
Compatible with biological materials.
Must not have mutagenic or carcinogenic properties
The first organic polymers used in orthodontics were
rubber and its sulfur cross-linked derivative, vulcanite (good
year 1840), polymethyl methacrylate (plexi-glass) was
synthesized by O. Rohm in 1936 and polyurethanes were
synthesized by O. Bayer in 1937. Along with these, other
more recently discovered polymers such as polycarbonates
and polysulfones have made it possible the manufacture
esthetic attachments.

STRUCTURE AND COMPOSITION
Polymers can be linear, branched or 3 dimensional.
First 2 types form carbon chain packed in lamellae, which are
folded in different ways without being inter-connected.
Depending on their structure and molecular weight, their
properties can vary significantly.
Some coils maintain active chemical functions, which
allow them to bond with other molecules through bridges or
cross-links, thus restricting their movement. If these bonds
are few, the stretched material returns to its previous form
after mechanical activation.

ELASTICS
Slightly cross-linked polymers exhibit some flexibility
and elasticity as well as greater toughness and on increased
resistance to stress and abrasion. As the number of bridges
between the coils increases, the material becomes
considerably harder and more difficult to stretch.
STRONG ELASTICS
The highly cross-linked polymers form a tri-
dimensional network. These bridges render the material
hard, insoluble and impossible to reshape by heating. A pre
polymer obtained from an aromatic diisocyanate, which are
semi-crystalline, hard and are dispersed in an amorphous
matrix, soft, low molecular weight diol. Because of the hard
segment of the polymer, the stretching energy is partly
dissipated. The initiation of cracks is delayed and deflected,
and the stress concentrations are relieved. These features
exist in the plastic bracket.

PLASTIC BRACKET
These brackets were described and tested by Newman
in 1969. They had limited popularity because of the
following clinical problems :
Staining and discoloration.
Poor dimensional stabilities, so that is not possible to
provide precise bracket slots or built in all the straight wire
features.
Friction between the plastics bracket and metal arch wires
that makes it difficult to slide teeth to a new position.

Most efforts are directed towards improving the
polymeric brackets by reinforcing that plastic matrix, apart
from strength and esthetics. Other benefits are, the
roughness brought by the addition of fillers - conditions of
the plastics base. Polyurethane and polyesters alike have
been reinforced with powder or fibres - steaming both
stiffness and strength.

PARTICLE OF FIBRE REINFORCED BRACKETS
CURRENTLY AVAILABLE
Polymer fiber reinforcement - Goldberg
Glass reinforcement - Adam et al,
Mineral filler reinforcement - Masuhara

Ceramic liner - Sernate
Metal liner - Wall Sherin
Metal reinforcement - Andrew

PHYSICAL PROPERTIES
Polycarbonates have high strength and modulus.
Show little elastic deformation under load.
Solvents attach them.
Ductile in nature.
They show low co-efficient of friction against stainless
steel but under excessive rapid force result in high co-
efficient of function.
It reacts with the acrylic adhesive enhancing adhesion of
the adhesive attachment interface.
It has relatively low water absorption but over a period of
time it becomes soft.

BOND STRENGTH
In vitro, bond tests reveal that mean bond values of
about 5.10 Mpa, when used with a plastic conditioner as
recommended by a manufacture. When used without such
conditioner, the value is 4.36 Mpa, which may not be
clinically adequate. Miura had stated that 5.1 Mpa is the
desirable value for satisfactory clinical performance.
These brackets do not show any tendency for brittle
fracture like ceramic bracket and do not posses and hazard in
de-bonding. They may be de-bonded like metal brackets. No
enamel damage unlike ceramic brackets is consequent in de-
bonding. They cannot be recycled satisfactorily.

COMPOSITE BRACKETS
A composite is a multiphase material brought about
by combining materials that differ in composition or form in
order to obtain specific characteristics and properties. The
constitutes retain their identities and properties such that
they exhibit an interface between one another and act in
concert to achieve improved synergistic properties not
obtainable by any of the component acting alone.

In orthodontics, the 1st
composite resin were launched
in 1950s and the first attachments in the mid 1990s. In
composites, the particles are dispersed in the polymer
matrix. As a result, the whole material composed of several
phase. Each of these components phase can possibly be
made of other phases. E.g. metal slot is inserted into a
ceramic powder - reinforced plastic.

STRUCTURE AND COMPOSITION
Basic types of composite are the dispersion of the
fillers (a discontinuous phase made up of round or
irregularly shaped particles, fibers and whiskers), in a binder
or matrix (continuous phase made up of metal, ceramic or
resin). The physical mixtures with properties that lie some
where between the values of their constituent material are
known as blends.
In composite, matrices are weak link, under load,
these are the first to crack and craze. This can be reduced by
adding fibers (filler) to the matrix. By keeping the reinforced
fibers together in the right orientation and position and by
transferring and distributing the load, matrices protect fibers
against chemical attack and during handling, this renders
composite remarkable for their strength and endurance.

The most efficient filler are the stiff fibers, these fibers
reduces the slip between the plans of atoms. The preferred
orientation achieved by adding oriented fibers changes the
shape of the macromolecules. Because of high strength and
stiffness, material usually fail, as a result of flawed
propagation, fibers limits the destruction phenomenon to the
length of their size. A flaw in a fiber cannot lead to failure of
the entirely assemblage. Adding whiskers to the matrix
results in increase in the strength of the material. They
measure about 0.5 MM in diameter and 40 to 50 MM in
length. Whiskers can be handled in a manner similar to
powder.

COUPLING AGENT
Filler matrix interface within composite plays a major
role. Its defects or weakness can severely limit
performances. Void of affinity, the components do not
behave as a whole easily disassembled. For this reason,
coupling agents are used. In orthodontics, the best-coupling
agent is the silanes, which are extensively used both for
treating fillers entering the composite adhesive and for
adhesion of ceramics.
A variety of materials such as metals, plastics and
ceramics can be used both as matrices and reinforcements.
The most common combination used in orthodontics is the
reinforcement of polymer with ceramic, metals and other
polymers of ceramic with metals and of metals of ceramic.

SYNTHESIS
Method of making composite are based on the
controlled additional pretreated solid fillers to the liquid /
Melton matrix of the synthetic resin. For composite brackets,
the preferred manufacturing method is injection molding.
The process is based on forcing into a mold, a dispersion of
filer in polymer at controlled temperatures.
To avoid contamination and discolouration, clean,
non-metal apparatus must be used throughout. The future
may bring so called molecular mixing in which rigid
backbone molecules are uniformly dispersed in a matrix of
flexible polymers. Such composites are expected to have
superior impact resistance and compressive strength,
retaining their optical properties.

COMMERCIALLY AVAILABLE COMPOSITE
BRACKETS ARE :
Plastic reinforced with ceramic - Lee Fisher (Lee Pharm)
Plastic reinforced with glass - Image (GAC)

Plastic reinforced with ceramic - Value line (Uree)
Plastic reinforced with ceramic - Silkon (Am Ortho)
Plastic with metal insert - Spirit (Ormco)

Plastic with metal insert - Spirit MB (Ormco)
Plastic with metal insert - New plastic (Tomes)
Ceramic with metal insert - Clarity R (Unitek)

Plastic reinforced with ceramic and metal insert - New
spirit (Ormco)
Metal with plastic base - Ceramic moflex (TP Ortho)
Plastic reinforced with glass - Self locking - Oyster (GAC)

CERAMICS
Esthetics constitutes an important consideration in
orthodontics. Demand for esthetics in treatment has been
reason for change in bracket morphology and material.
Ceramic bracket was first introduced in 1987 and today it
has found wide acceptance and still holds more promise.

They are classified on the basis upon:-
1. The crystal structure into more crystalline or polycrystalline
brackets.
2. It may be classified depending on its retentive mechanism
into
- Mechanical
- Chemical
- Combination – mechano chemical
3a. Based on the material constituents into
- Pure ceramic
- Laminated ceramic
3b. Based on the material constituents
- Alumina based
- Zirconia based materials.

PROPERTIES
A very important physical property of ceramic bracket
is the extremely high hardness of aluminium oxide and
Zirconium. Both mono crystalline and polycrystalline,
alumina has a significant advantage over stainless steel.
Because ceramic brackets are at times harder than stainless
steel brackets or enamel. Tensile strength is much stronger
in mono crystalline alumina than in polycrystalline alumina
that is in turn significantly stronger than stainless steel.

Tensile strength characteristics of ceramics depend on
the condition of the surface of the ceramic. A shallow scratch
on the surface of a ceramic bracket will drastically reduce the
load required for fracture. Fracture toughness in ceramics is
20 to 40 times less than in stainless steel making it much
easier to fracture a ceramic bracket than a metallic one.
Among ceramic materials, poly crystalline alumina presents
higher fracture toughness than single crystal alumina.

BOND STRENGTH
Ceramic material does not bond chemically with
adhesives, ceramic brackets derive their strength from the use
of silane-coupling agent on the base of the bracket, through
groove for mechanical retention or both.
Laboratory testing of mechanical retention indicates
that adhesive to bracket bond strength of ceramic is lower
those equivalent size foil/mesh metallic brackets.

Ceramic bracket base have considerably fewer mechanical
undercuts than these found in mesh base design therefore
ceramic brackets might be expected to have greater bond
failures rates if they are used without a silane coupling agent.
According to the system of chemical bonding, glass is
added to the aluminum oxide base and is treated with a
silane-coupling agent. Silane bonds with glass and leaves a
free ends of its molecules that react with any of the acrylic
bonding materials.

The presence of different behavior between
mechanical and chemical bonding is due to the way stress
concentration is distributed over the bonding surfaces.
Ceramic brackets that offer a mechanical bond with the
adhesive have retentive grooves in which edges are 90°.
There are also cross cuts to prevent the brackets from sliding
along the undercut grooves that have sharp edge and
resulting in brittle failure of the adhesive.

One application of shear bonding force part of the
adhesive is left on the tooth and part on the grooved brackets.
On the other hand, the shiny surface of ceramic brackets
bonded chemically allow a much greater distribution of stress
over the whole adhesive interface without the presence of any
localized stress bond is needed to cause de – bonding and
pure design, but also by various other factors including type
of bonding resin, etching time, condition, and preparation of
teeth.

FRICTIONAL RESISTANCE
Stainless steel brackets generate lower frictional than
ceramic bracket. The injection-molded ceramic bracket
creates less friction than other ceramic bracket and then wide
metallic or ceramic bracket creates less friction then narrower
brackets of the same materials. Comparison of frictional
forces produced in ceramic and stainless steel materials, the
different wires are used, suggested that for most size, the
wire in ceramic brackets produced significant greater friction.
Also beta- titanium and nickel-titanium wires were
associated with higher frictional force than stainless steel
cobalt-chromium wires. To reduce frictional resistance,
development of ceramic brackets with smoother slot surfaces
and consisting have metallic (clarity brackets) or
ceramic/plastic slot surfaces was considered and it has been
accomplished.

BASE SURFACE CHARACTERISTICS
Currently there are 3 types of ceramic bracket base,
available:-
Type 1 : Bracket base is formed with undercuts or grooves
that provide a mechanical interlock to the adhesive. These
brackets may have a flat base, covered with silane
layer with recesses for mechanical anchoring. This structure
minimizes the parameters of mechanical retention, compared
with other base.
Type 2 : Bracket base has a smooth surface and relies on a
chemical coating to enhance bond strength. A silane –
coupling agent is used as chemical mediation between the
adhesive resin and the bracket base because of the insert
composition of the aluminum oxide ceramic brackets. The
manufacturers of the such brackets have reported that they
achieve higher bond strength when compared with
mechanical retention.

Types of ceramic brackets base
Bracket base designs of
brackets tested: A, Allure
IV x 35, B, Ceramaflex x
19, C, Intrigue x 23, D,
Transcend 2000 x 18, and
E, DynaBond II x 18.

Type 3 : Bracket has a thin poly carbonate laminate on the
base, (plastic breaking attachment) to which premier is
treated before chemical bonding the plastic will bend and
allow for a separation between the brittle ceramic and the
enamel, fracture site were at the adhesive bracket base
interface and 90% of the sample, the plastic water remained
on the tooth with the adhesive.

BRACKET FRACTURE
The breakage of ceramic bracket is a problem related
to the low fracture toughness of the aluminum oxide, and the
ability to resist it depends on the type and shape and bulk of
the material present. Bracket breakage might occur either in
function or in the de-bonding process. Investigation on
torsional , shear and peel de-bonding of ceramic brackets
reported differences on the incidence of bracket fractures and
on the fractured parts between different types of brackets. As
primary causes of fracture, the internal defects and
machining interface.

Bracket – wing fracture is frequently problems,
encountered by clinician. When ceramic bracket break
during orthodontic treatment, the patient is subjected to
increased chair time. There is also potential health risk due
to the possibility of swallowing or aspirating bracket
fragments, which would be difficult to locate because of the
radiolucent nature of alumina.

Second order wire activation’s do not usually cause
ceramic bracket failure, unless the bracket during treatment.
Third order wire activation may be more likely to cause
ceramic bracket failure but it seems that in most real situation
the fracture resistance of the ceramic brackets during arch
wire torsion appears to be adequate for clinical use.
Orthodontics should be aware of the brittle nature of
ceramic brackets. Extra care should be undertake during
treatment to avoid scratching of the bracket surface with the
instruments. Careful ligation is necessary, coated ligature
are recommended to prevent tie wings fractures.

RECYCLING CERAMIC BRACKETS
Recycling of ceramic brackets are done by heating,
comparison of de-bonded ceramic bracket base with those of
recycled brackets after heating and application of the silane
coupling agents suggested that “recycling” method is
effective in providing clean surface. Bond strength of
recycled brackets appeared to be clinically adequate,
although it was significantly lower than of new brackets. The
weaker bond strength after “recycling” of ceramic brackets
minimizes the likelihood of unwanted enamel removal
during de-bonding.

CERAMIC BRACKETS
Manufactures introduced ceramic brackets to eliminate
the problem of the unesthetics appearance of stainless steel
bracket without the disadvantage of plastic bracket. The
current ceramic bracket composed of either mono crystalline
or polycrystalline.
Mono crystalline brackets are manufactured by
heating aluminum oxide to temperature in excess of 2100C.
The molten mass is cooled slowly, and the bracket is
machined. The bracket is then that treated to remove surface
imperfection and relieve stress created by the cutting
operation.

Blending aluminum oxide particles with a binder and
molding the mixture into a shape from which a bracket is
machined or by injecting mould manufacture polycrystalline
brackets.
Temperatures in excess of 1800°C are used to burn out
the binder and fuse the particles together. The most apparent
difference between polycrystalline and single bracket is in
their optical clarity. Single crystal brackets are noticeable
clearer than polycrystalline brackets, which tend to be
translucent. Both single crystal and polycrystalline brackets
resist stains and discoloration.

ZIRCONIA BRACKETS
Zirconia is tri-dimensional inorganic macromolecules.
Their ionic, crystalline structure accents for its hardness and
compressive strength , which exceeds that of metals. At room
temperature, pure zirconia exists in the monoclinic phase.
When heated to 1000°C pure zirconia transforms to the
tetragonal phase, which is accompanied by a substantial
volume change that is structurally catastrophic. Crack
formation can be inhibited by addition of 4-6% of a stabilizing
oxide like calcia, yttria or magnesia. This partially stabilized
zirconia (PSZ) results from the retention of some tetragonal
particles at temperature between the normal transformation
temperature ranges. Increase in the volume known
“transformation toughening” protects the ceramic by
arresting the propagation of cracks.

When compared with aluminum PSZ are make up of
smaller grain sizes and has higher fracture strength.
Fracture toughness of partially stabilized zirconia is about
3 times that of aluminum.
Low frictional co-efficient achieved with PSZ.
Zirconia brackets do have problems related to color and
opacity, which detracts from the esthetics can inhibit
composite photo polymerization.

New collapsible ceramic bracket
A new collapsible ceramic bracket designed with a
metal lined arch wire slot, a vertical slot designed to help
create a consistent failure made during de-bonding.
The new bracket is tough combine the aesthetic
advantage of ceramics and the functional advantages of de-
bonding metal brackets.

The advantage of having stainless steel slot to minimize
the increased friction that occurs as a result of arch can
function ceramic furthermore. The metal slot helps to
strengthen the bracket order to withstand torque forces.
The new bracket also incorporates a vertical slot (0.019
inches and 0.018 inches) in width and depth designed to help
create a consistent bracket failure made during de-bonding.
The vertical slot can also be used to insert auxiliaries such as
uprighting spring.

DEBONDING BRACKET WITH PLIER
The collapsible ceramic brackets were de-bonded
according to the manufactures directions with a weingart AEZ
plier. The tip of the weingart plier was placed over the mesial
and distal ends of the metal lined arch wire slot. The tie
wings are the squeezed gently until the bracket collapses. It is
critical that the tips of the plier be placed over the ends of the
metal slot and not over the bracket base.

PROBLEMS ENCOUNTERED IN CERAMIC BRACKETS
I. Enamel fracture and flaking or fracture lines in during
de-bonding . Solution :
Avoid sudden impact loading or stress concentration
within the enamel by using proper de-bonding techniques.
Do not bond ceramic brackets on structurally damaged
teeth.
- Reduce bond strength.
- Mechanical retention
- Laminates
- Reduce chemical adhesive (silane to reinforced
mechanical retention).
- Adding metal mesh of the base of the bracket.
- Use of weaker resin.
- Modify the thickness of the adhesive use.
De – bonding with ultrasonic, electro thermal and laser
devices.

II. Attrition of teeth against ceramic bracket.
Solution:
Select the teeth to be bonded.
Adding composite over the interference point
III. Increased friction with ceramic bracket
Solution:
Develop of bracket with smoother slot
Avoid less of anchorage by building up the anchorage.

IV. Increased pain or discomfort while de-bonding ceramic
brackets
Solution :
Have a bite with pressure on cotton roll and or gauze
during de-bonding.
V. Limited rotation of teeth with ceramic bracket.
This problem mainly affects bracket designed because they
are necessarily the smallest and bulkier than metal brackets
as this required for sufficient resistance to fracture.

DE-BONDING TECHNIQUES FOR CERAMIC BRACKET
Heat removal of ceramic bracket.
Heat the tip of the utility plier for about 10 seconds with
micro torch with light rotation force bracket is removed.
Removal of excess adhesive from mesial, distal and incisal
portion of the bracket base with No. 7901 tapered finishing
bur. Bracket is removed using unitek de-bonding instrument
No. 800-804 using quick circular motion. If the bracket
fractures, remove the rement with ‘A’ company de-bonding
plier No. 079-960. In case small bracket remant can be
moved with diamond but in high-speed hand piece.

CONVENTIONAL TECHNIQUES OF BRACKET
REMOVAL
This recommended by the manufacture were
effective, required little expenditure of time and did not
result in significant enamel damage under the condition
employed.
Disadvantages :
Enamel fracture
Aspiration of bracket fragments by point
Patients discomfort

ULTRASONIC BRACKET REMOVAL
Ultrasonic de-bonding approach includes a decreases
chance of enamel damage and decreased bracket failure.
Removal of the adhesive after de-bonding can be
accomplished with same ultrasonic tip.
Disadvantages :
Increased de-bonding time.
Excessive wears of expensive ultrasonic tip.
Need to apply moderate force level (sensitive).
The Potential for soft tissue injury by a careless operator.
The need for a water spray to reduce the heat build up and
minimize any possible pulp damage.

ELECTRO THERMAL DE-BONDING
ETP method reduces the incidence of bracket failure,
small amount of force required to break the bond minimal
for enamel damage.
Disadvantages :
Potential for pulpal damage
Increase in the temperature of the hand piece, which has
the potential to cause patient discomfort on mucosal
irritation.
Bulky hand piece design, which makes its intraoral use
difficult in the premolar region.
Instruments is designed to fit specific bracket design.

LASER DE-BONDING
CO2 and ND are used.
It is “Cold” universal de-bracketing instrument.
Advantages:
Significantly reduction de-bonding force.
Potential to be a traumatic
Less risk of enamel damage.
Contra indication of ceramic bracket
Deep bite case.
Patient with bruxing teeth with cracks on large restoration.
A need of significant incisor torque.
Children – due to brittleness of the ceramic bracket.

PROBLEMS WITH CERAMIC BRACKET
Incisal wears (Elastometric cover on the lingual incisor
helps in preventing attritional damage).
Frequent fracturing of tie wings.
Difficulty of torquing and tipping
Increase arch wire friction.
Longer treatment time.
Under finishing
Discomfort of bracket removal
Enamel damage during de-bonding
Ceramic bracket using mechanical appears to cause
enamel damage less often than using chemical retention.

InVu CERAMIC BRACKET
InVu has been introduced with significant
improvements in product design, low friction, bonding and
also reliable and safe characteristics.
Design Rationale
The InVu ceramic bracket has been designed to optimize
various key design parameters, such as :
Profile height (offers the lowest).
Low friction (comparable to metal brackets).
Ease of debonding (debonds just like metal brackets).
Good bond strength (only ceramic bracket offering a mesh
base).
Smooth radii on all edges to prevent archwire binding and
cutting of elastomerics.

True Twin Bracket Design
InVu incorporates a true twin brackets design. It has
four individual tie wings to allow for various modes of
ligation. The tie wings provide substantial overhang for
reliable ligation.
The mesiodistal aspect (arch wire slot length) is wide
enough to permit excellent tip translation and rotational
control. The inter-tie wing space is large enough to allow for
bracket position alignment using a flat bladed adjuster.

Profile Height
InVu brackets have the lowest profile height of anyt
ceramic bracket currently available.

Frictional Resistance - Archwire in Slot
Ceramic brackets traditionally show higher frictional
resistance as compared to metal brackets. The InVu ceramic
brackets are made by an injection molding process, which
produces an extremely smooth surface as compared to
brackets that have machined surfaces.
InVu - TP Signature III - RMO

InVu surface yields a lower friction force as compared
to rough machined surfaces. InVu brackets have smooth
rounded edges at the mesial and distal edges of the archwire
slot to reduce static friction.
Virage -
American
Mystique -
GAC
Clarity -
Unitex
Inspire -
Ormco

InVu - Advanced Bonding Mesh Base
InVu ceramic brackets have an advanced bonding
base that replicates the mesh architecture of the mesh in
metal brackets. This high strength, polymer mesh base
provides for excellent mechanical and chemical bonding to
most orthodontic adhesives.

TOOTH COLOURED ARCH WIRE
Composite
Composite prototype arch wires have been made
from S-2 glass fibers and acrylic resin. Such composites are
esthetically pleasing because their translucent quality tends
to transmit the color of the host teeth.
They are quite strong and springy.
Processed by photo pultrusion and by Electro magnetic
radiation.
Arch wire prototype have been constructed with stiffness
from that of nickel titanium to beta titanium. This
variability can be achieved without a change in other over
all cross sectional dimensions.

When the fiber and resin content are equal, spring back is
greater than 95% so that the energy applied at the wire
insertion point may be retrieved months later without
significantly loss.
The water absorption of fiber resin content is only 1.5% by
weight so that dimensional stability is good of stain and
odour is minimized.

COMPOSITE ARCH WIRE MANUFACTURING
PROCESS
In the photo-pultrusion process, fibers are drawn into
a chamber when they are cured, uniformly spread and
coated with monomer. The wetted surfaces are then
reconstituted into profile of specific dimension via a die
from which they then exit into a curing chamber. As the
photons of the light polymerizes, the structure quickly into a
composite. After final dimension of the desired profile, the
cure is completed and the material is taken up in a form of a
large spool.
If further shaping or sizing of the profile is required,
however, the composite is only partially cured. This staged
material is further processed using a second die and staged

ESTHETIC RETAINERS
(QCM) organic polymer retainer wire made from
1.6mm diameter round polytheline terephthalate. This
material can be bent wit 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). In pre-
fabricating, the QCM retainer wire, the anterior portion of
the wire and the “wave” portion are heat–treated at about
150°C immediately after bending.

These wires showed a module of electricity similar to
that of flat bow retainer wire.
After heat-treated it displayed little deformation.
More shrinkage during heating was observed in the
posterior segment of the arch wire, which was compensated
by posterior segment.

No significant discoloration of QCM was noted indicating
that it does not esthetic quality.
New esthetics organic polymer.
They are made up of (poly ethylene terephthalate).
The new version, easy to fabricate and fit to the dental
arch.
It requires no special tools or instruments only and
ordinary hair dyer.

New Version of Esthetic Retainer

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.

FIBER REINFORCED COMPOSITE
FRC materials have the potential to replace metals in
clinical orthodontics. Unlike metals, a FRC has good
bonding characteristics not only to the tooth, but also to
appliance itself.
FRC can be bonded to another FRC and also attachments
like brackets hooks etc can be added directly.
FRC materials are superior to polymers because they offer
a structural material of improved rigidity and strength as
well as reduction in stress relaxation. They are highly
formable and can be fabricated in complex shapes.

They are available in 3 configuration:-
- Rope type (round) used as fixed retainers
- 2mm wide strip where the fibers are in unidirectional
parallel configuration.
- Woven pattern, they have best mechanical properties.
Application of FRC to the tooth involves a straightforward
technique, either direct or indirect.

ACTIVE APPLICATION
Engagement inter-maxillary
elastics without bonding or wires,
eliminating wire racket play.
Full arch FRC used in vertical
elastics to close open bite where
incisor extrusion is indicated.
Extrusion only of maxillary
incisor segment for open bite
closure, using mandibular full bar
as anchorage unit.

Posterior anchorage unit and
active anterior unit with bonded
attachment used for esthetics
space closure.
Uprighting second molar with
full FRC from 1st
molar to 1st
molar. Absence of brackets
allows greater, more efficient
inter-bracket distance between
bonded attachments.

For maxillary anterior
intrusion with 4 incisor joined
to form active connection.
Tube is placed on posterior
connector of continuous TMA
intrusion arch wire, which
applies force of bonded button
or hook attached to the anterior
segment.
Fixed lingual retainer.

PASSIVE APPLICATION
For bonded tooth-to-tooth
retainer
Maryland bridges, to replace
missing lateral incisors
LIMITATIONS
They are weak in shear and torque force.

MANUFACTURING PROCESS
The fibers correctly oriented and an excellent coupling
is achieved, followed by an initial stage of polymerization of
the matrix. This initial polymerization makes the matrix
flexible and adaptable, so it can be easily contoured to the
teeth. The result is a user-friendly polymer that is easily
manipulated as any plastic, but as structurally stronger as
metals. The modulus elasticity is 70% greater than that of a
highly filled dental composite. Yield strength is 6 times
greater than the dental composite and 24 times greater
resilient than a dental composite.

AN ORGANIC POLYMER ORTHODONTIC APPLIANCE
We have developed a new, esthetic orthodontic appliance
(QCM) in which the brackets, wires and attachments are all
made of polycarbonate, an organic polymer.

Appliance Design
Plastic wires with homogenous cross-section do not
exert as much force as metallic wires of identical size. These
dynamic can be explained by the principle that "bending
stiffness is directly proportional to the geometrical moment
of inertia, which is function of the shape of the cross section
of the object, regardless of the nature of its material or the
magnitude of force applied on it". According, we made the
cross-section of the plastic wire a "T" shape to yield the
geometrical moment of inertia that would generate sufficient
forces for tooth movement.

To hold the wire and efficiently transmit the force to
the tooth, the bracket was given a "C" cross-section. The
plastic arch wire is normally inserted into the brackets by
sliding it from the canines to the posterior teeth, then
snapping it into the incisor brackets without ligation.
Cutting it between brackets with a pin-and-ligature cutter,
then sliding it out with a plier removes it.
The molar brackets also serve as buccal tubes, unlike
those conventional systems.

Bending test
A bending test was carried out to compare the new
wire with existing metallic wires. The wires are deflected 2
mm, at a speed of 90 microns/minute, in a load - unload
cycle. The force deflection curve on the plastic wire rose
uniformly up to 1mm, at which point the curve gradually
leveled off.

On unloading, the deflection curve dimensionally
rapidly until it reached 0.4mm of permanent deformation.
Although this permanent deformation was greater than that
of the metallic wires, the polymers exerted adequate force
on the tooth.
Although the polymer arch wire is able to exert
enough force to move a tooth, the force diminishes more
rapidly than it would with metal wires. To overcome this
disadvantage, we replaced the wires at shorter intervals
(every two or three weeks during the leveling stages).

OPTIFIEX ARCH WIRES
New orthodontic arch wires designed by Dr. Taloss
and manufactured by ORMCO. It has got unique
mechanical properties with a highly elastic appearance.
Made of optical fibers.

It comprises of 3 layers.
A silicon dioxide core that provides the forces for moving
teeth.
A silicon resin middle layer protects the core from
moisture and adds strengths.
A stain resistant nylon outer layer that prevents damage
to the wire and further increases its strength.

Optiflex possess 5 advantages, which makes it a unique arch
wire in terms of esthetics and mechanical alike:-
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. The yellowish stain commonly seen in
elastomeric ligatures and chains will be never being
observed in optiflex.

Beyond esthetics, optiflex is very effective in moving the
teeth using light continuous force. The force applied with
optiflex is approximately equal to half the force with a
corresponding with other arch wire of similar size.
Optiflex is very flexible. It has an extremely wide range of
action. When indicated it can be tied with elastomeric
ligature malaligned teeth without the fear of fracturing the
arch wire.
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.
Avoid using instrument with sharp edges like the scaler,
tie and tuckers etc, to force the wire into the bracket slot.
Instead apply gentle force with your finger to insert the arch
wire into the slot.

The cut end of the arch wire, distal to the molar 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.

Optiflex has got the following clinical applications:
It is used in adult patient who wishes that their braces not
be really invisible for reason related to personal concern or
professional consideration.
It can be used as an initial wire in cases with moderate
amounts of crowding in one or both arches.
It should be used in cases to be treated without bicuspid
extraction. Optiflex is not the ideal arch wire for major
cuspid retraction. Retracting cuspid in the extraction cases
with optiflex has been disappointed 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 10
to 6 inch, straight lengths of 0.017 inch and 0.021 inch.
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),
0.4698 grams for a defection of 4.46 mm.

MARSENOL
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.

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.

TOOTH COLOURED LIGATURE WIRE
Teflon Coated Ligature Wire
It does not discolor.
Grayish hue of these wires makes them esthetically
interior.
Teflon coating wear off after 2-3 weeks exposing the metal
surface of the wire.

Teflon coated stainless steel ligature produces less friction
than elastomeric ligature regardless of bracket type, arch
wire type or bracket wire angulations.
Teflon coated ligature, as an alternative to the clear
elastomeric ligature appears to partly reduce the high
frictional resistance of ceramic bracket.
Teflon coated ligature generates lighter force of
engagement of the arch wire into the bracket slot.

Composite ligature wire
Fabricated from the acrylic monomer n-butyl
methacrylate and drawn as polyethylene fibers by use of
photo-putrusion manufacturing process. the stress
relaxation characteristics of the composite matrix will
transfer the strain to the stronger polymer fibers, 98% of the
stress is lost within few hours. Such a loss of force is critical
for optimal sliding mechanics .

RETAINERS
Essix Appliance
Sheridan and Colleagues have developed the Essix
appliance as a passive retainer and as a device for active
minor tooth movement.
Uses
1. For correction of anterior cross-bite.
2. For correction of bilateral posterior cross-bite.
3. For correction of ectopic canines.
4. Used as a retainer for anchorage.

Two key steps are involved :
1. Improving the retention of the Essix appliance so that
intra or interarch elastics can be attached without dislodging
it.
2. Adopting the appliance for elastic attachment.
Undercuts for improved retention
Adding undercuts in the Essix embrasure areas
makes the appliance more tenacious. Use the Hilliard
Undercut Enhancing Thermoplier for this purpose.
Alternatively, Sheridan prefers to create the undercuts in the
dental cast before vacuum-forming to avoid stretching and
weakening the Essix material with the plier.

If the thermoplier is used, the Milwaukee Heat Gun is
a quick and inexpensive device that can be used to heat it.
The heat gun is directed at the beaked end of the Hilliard
plier for 12 – 15 seconds, and the plier is then immediately
pressed into the interproximal areas of the Essix appliance as
needed for added retention.

Attaching Elastics
We have tried various means for attachment of
elastics, including the Hilliard Elastic Hook-Forming
Thermoplier and ball hooks vacuum-formed into the Essix
material is one we call the “Rinchuse Slit”. Use a scissor to
cut a slit into the type of Essix appliance, with the location
and angle determined by the direction of the elastics.
Any type of elastic traction can then be used from
maxillary to mandibular Essix appliances from an Essix
appliance to fixed orthodontic appliances, from an Essix
appliance to a face mask.

INVISALIGN SYSTEM
The frequency of malocclusion in adults is equal to or
greater than that observed in children in adolescents.
Crowding and spacing are among the most common
problems in adults.

Despite their need for orthodontic treatment,
however, adults are often averse to wearing traditional fixed
appliances with wires, bands, and brackets. The Invisalign
System how makes it possible for orthodontics to offer adult
patients requiring full-mouth orthodontic treatment an
esthetically agreeable solution, using a computer-assisted
technology that produces a series of clear plastic overlays.

Clear plastic overlays appliances take a variety of
forms,
Retainers
Night guards
TMJ splints
Bleaching trays
Invisalign System, to take a single impression of a
patient’s dentition, and use that to:
Create a final setup
Project stages of tooth movement from the initial state to
the final state.
Create a series of clear, custom-made appliances, called
“aligners”, that move the teeth according to the projected
stages of movement.

Patient Selection and Records
A candidate for orthodontic treatment with the
Invisalign System,
Should have fully erupted permanent teeth.
Growth should be completed.
There are is no age requirement but full time wear is
mandatory.
Usual orthodontic records are including
Study casts
Photographs
Radiographs

Polyvinyl siloxane impression material must be used
because it yields highly accurate impressions that remain
stable for as long as three weeks and allow multiple pours.
Fabrication of Aligners
To ensure a high degree of
accuracy throughout the
process, impressions are
taken of your teeth by your
doctor.

Your doctor sends Invisalign
your impressions which are
used to make plaster models of
your teeth.
Using advanced imaging
technology, Invisalign
transforms your plaster models
into a highly accurate 3-D
digital image.

A computerized movie - called
ClinCheck- depicting the
movement of your teeth from the
beginning to the final position is
created.
Using the Internet, the doctor
reviews your ClinCheck file - if
necessary, adjustments to the
depicted plan are made.

From your approved ClinCheck
file, Invisalign uses laser
scanning to build a set of actual
models that reflect each stage of
your treatment plan.
Your customized set of aligners
are made from these models,
sent to your doctor, and given to
you. You wear each aligner for
about two weeks.

After wearing all of your
aligners in the series, you get the
beautiful smile you’ve always
wanted.

CONCLUSION
Advances in Orthodontic biomaterials is seen
regularly. More so in tooth coloured materials due to
increased esthetic concern of orthodontic patients. The day
is not far off when all attachments will be made in tooth
coloured materials.

Dr.amit tooth coloured-presentation

Dr.amit tooth coloured-presentation

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