Bonding aftab

BONDING IN
ORTHODONTICS
www.indiandentalacademy.com

CONTENTS
1.Introduction
2.History & Pioneers
4.Bonding Materials(Types)
-Self-cure
-Light-cure
-Dual-cure
5.Light-cure units(types)
6.Preparation for Bonding

7. Bonding techniques
a) Direct
b) Indirect -Labial & Lingual
8. Bonding strength and the procedure
for study of bond strength
9. Failures in Bonding
10.Recycling procedureswww.indiandentalacademy.com

11. Debonding Techniques
12 Microscopic structure of a good bond
13. Bonding procedures for-
-Hypo plastic teeth
-Acrylic crown
-Porcelain crown
-Metal crown
-Gold crown
14. Conclusion.

Bonding of attachments, eliminating the
need for bands, was a dream for many
years before rather abruptly becoming a
routine clinical procedure in the 1980s.
Banding is based on the
mechanical/chemical locking of an
adhesive to irregularities in the enamel
surface, and to mechanical locks formed in
the base of orthodontic attachment.

Successful bonding in orthodontic,
therefore, requires careful attention of
three components of the system: the tooth
surface and its preparation, the design of
the attachment base and the bonding
material itself.

What is bonding?
WHAT WAS THERE BEFORE
BONDING

Advantages of bonding over
banding
Optimal performance in bonding of orthodontic
attachments offers many advantages when
compared conventional banding.
1. It is esthetically superior
2. It is faster and simpler.
3. Less discomfort for the patient
4. Arch length is not increased
5. Bonds are more hygienic than band improved
gingival and periodontal condition
6. Partially erupted teeth can be controlled

7. Mesiodistal enamel reduction is possible during
treatment.
8. Attachments may be bonded to artificial tooth
surfaces and to fixed bridgework
9. Interproximal areas are accessible for complete
buildups.
10.Caries risk under loose bands is eliminated.
11. No band spaces are present to close at the end of
treatment.
12. Brackets may be recycled, further reducing the
cost . www.indiandentalacademy.com

History & Pioneers

• The development of the bonding procedure
has revolutionized the use of fixed
orthodontic appliances.
• Although the molars are the only teeth that
are commonly banded, many practitioners
today exclusively bond all fixed appliances
including the molar using bondable molar
tubes.

Over the years, refinements have taken
place both in the bonding techniques
as well as in the materials that are
used for bonding.
The history of Bonding goes back all the
way to the 19 50’s and the acid-etch
bonding technique has led to dramatic
changes in the practice of orthodontics

.
Buonocore in ’55 demonstrated
increased adhesion by acid
pretreatment, using 85%
Phosphoric acid.
Newman began to apply this finding
to direct bonding of orthodontic
attachments.
.

Retief also described an epoxy resin
system to withstand orthodontic
forces.
• Smith in 1968 introduced zinc
polyacrylate cement and bracket
bonding with this cement.

• In 1971,Miura et al described an acrylic
resin(orthomite), using a modified
trialkyl borane catalyst that proved
successful for bonding plastic brackets
and in presence of moisture

BONDING TECHNIQUES
DIRECT BONDING INDIRECT BONDING
LINGUAL BONDING
FACIAL BONDING

BONDING ADHESIVES
Composite resins
Chemical cure
Light cure
Dual cure
Electrothermal cure
Glass Ionomer
Cements
Acrylic Resin
Compomer
Hybrid Ionomer

• Chemical cure adhesives are the ones in which
two components of adhesives interact.
• The light-cure system is polymerized via
exposure of a high intensity visible light.
• The dual cure system cure with or without
exposure of visible light.
• The choice depends upon personal performances
keeping in mind, however that orthodontic
adhesives are low film thickness, meaning that
they have a higher strength in a thin layer than in
a thick www.indiandentalacademy.com

Electro thermal bonding:
In 1979, Voster introduced the concept of
electrothermal bonding by raising the temp. of
the resin.
Reduces the setting time of chemically cured
bonding resin by 4-8 second.
The pulp chambers of a mandibular incisor,
the most sensitive tooth, increased by only 2o
c
after 3 pulses delivered at 2 sec interval.

GIC
• Recently introduced resin-modified glass
ionomer cement s (both chemical and light
cured)
• Bond to saliva-contaminated enamel
surfaces without phosphoric acid etching.
• The liquid contains polyarcylic and maleic
acid which remove contaminants and
change the enamel surface mechanically but
it will not create micromechanical retentionswww.indiandentalacademy.com

Glass-ionomer dental cements were
invented in the late 1960s by replacing the
phosphoric acid solution
The advantages of glass-ionomer
cements are:
* Self-adhesion to both enamel and
dentin.
* Fluoride release and re-release , without
dis-integration.
* Thermal expansion co-efficient similar
to dentin.
* No appreciable setting exotherm.
* Biocompatibility in appropriate host
environmentswww.indiandentalacademy.com

Hybrid GIC
• This are resin-reinforced water based
• Exhibited all necessary qualities for bonding.
• Debonding was less damaging to the enamel.
• Results no decalcification because of fluoride
• Can be used without acid conditioning
• Light curing activates free-radicals polymerization
of HEMA and two other monomers.thus forming a
poly-HEMA matrix immediately setting the
material.
• Eg,Fuji Ortho LC

Composotion
Powder Fluroaluminosilicate
glass
Liquid Copolymer of acrylic
acid
Malic acid
HEMA(2-
hydroethylmethaylacrylate
Water
Camphorquinone
Activator
Powder:Liquid 3gm:1gmwww.indiandentalacademy.com

Glass-filled resin GIC
• Also light cure
• Need acid conditioning to create larger area to bond
to enamel.
• Eg,Ultra bond LoK
Advantages-
1.Can be used in moist environment
2.Causes localized floride release
3.Has good bond strength
4.Debonding causes less damage to the under lying
Enamel

BONDING
PROCEDURE

Bonding Procedure :
The steps involved in direct and
indirect bracket bonding on facial
or lingual surfaces are as follows,
Cleaning
Enamel conditioning
Sealing
Bondingwww.indiandentalacademy.com

CLEANING

Moisture
control
Enamel conditioning
Enamel
Pretreatment

Moisture control
• Lip expanders and/or cheek retractors
• saliva ejectors
• Tongue guards with bite blocks
• salivary duct obstructers
• * Gadgets that combine several of these
• Cotton or gauze rolls
• Antisailalogues

Regarding antisailagogues both tablets
and injectable solutions of different
preparations, for example Banthine, Pro-
Banthine , atropine,surfate etc.)
Generally not needed for most patients.

When indicated, Banthine tablets (50 mg
per 100 lb [45kg] body weight in a
sugar-free drink 15 minutes before
bonding may providing adeduate
results

Enamel pretreatment ( Etching )
• After isolation, the conditioning
solution or gel (usually 37% phosphoric
acid) is applied over the enamel
surface for 15 to 60.
• To avoid damaging delicate enamel
rods, care should be taken not to rub
the liquid onto the teeth.

• The etchants is rinsed off the teeth with
abundant water spray.
• Next the teeth are thoroughly dried with
a moisture-and-oil-free air source to
obtain the well-known dull, frosty
appearance

Type and concentration of Acid
A. Liquid
B. Gel
Etching with 10% or 37% phosphoric
acid produces the highest bond strengths
(28MPa) to enamel.
The use of 10% Maleic Acid results in a
lower bond strength (18MPa).

No differences in bond strengths are
observed when enamel is etched with
phosphoric acid ranging in
concentration from 2% to 37%.

DURATION OF ETCHING
No differences between 15-second and
60-second etching with 37%
phosphoric acid; shorter etching time
causes less enamel damage on
debonding

Clinically, the etching of enamel creates
1. Microporosity within the enamel and
2. Reduces surface tension and allows the
resin to penetrae and polymerize within
the etched enamel rods.

Standard etchant dissolves about 5-10µm of
enamel surface and creates a zone of etched
enamel rods for about 15-25µm.
Etching process creates calcium
monophosphate and calcium sulfate by-
products that must be removed by a vigorous
water rinse

Resin composite does not bond well to
unetched enamel: however.
Hybrid Glass ionomer orthodontic
cement does not require etching and has
bond strength ranging from 8 to 25MPa.

1.Fracture and cracking of enamel
upon debonding .
2. Increased surface porosity - possible
staining
3.Loss of acquired fluoride in outer 10
µm of enamel surface .

4. Loss of enamel during etching .
5. Resin tags retained in enamel -
causing discoloration of resin.
6. Rougher surface if over - etched.

Air Abrasion
Also referred to as micro-etching is a
technique in which particles of aluminum
oxide are propelled against the surface of
enamel or another substrate by high air
pressure, causing abrasion.
Could eliminate acid etching;
Bond strengths to air - abraded enamel are
only about 50% of those to acid -etched
enamel.

Laser Etching
The application of laser energy to
an enamel surfaces causes localized
melting and ablation.
Results primarily from the micro-
explosion of entrapped water in the
enamel,some melting of the
hydroxyapatite crystals.

• Neodymium-yt-trium-aluminum garnet
produces lower bond strengths than
acid etching
• Used for 12 seconds at maximum
power (3W).

CO2 laser etching of enamel have shown
that bond strengths of 10 MPa can be
obtained

Crystal-Growing solutions
Another alternative is to grow crystals on the
enamel surface.
• Involves application to enamel a poly(acrylic
acid) containing sulfate ions.
• This causes growth of calcium sulfate
dihydrate crystals on the enamel surface.
• This in turn retains the adhesive.
• Bond strength 60-80% of strength obtained
with etching.
• Easier to debond,less adhesive left on tooth
and less damage to enamel.www.indiandentalacademy.com

SEALING ( PRIMER / COUPLING
AGENT )
• This make the surface more amenable to
accept a bond.
• Mainly hydrophilic monomers,carried in
solvent-Acetone,ethanol-water or water.
• Hydrophilic molecules,(HEMA,coupling
agent)
• This wet the surface for better
penetration of monomer.

Acidic primers (self etching primers)
Use of acidic primer to bond restorative
composites to enamel and dentin.
Comparable bond strengths are found when
used with highly filled resins.
Unique characteristic:
Contains conditioner (phenyl)
Primer (HEMA,dimethylacrylate) agents into
a single solution

Moisture -Resistant primers
Moisture resistant primer (Transbond) to etched
enamel that has been contaminated with moisture or
saliva.
This primer is a hydrophilic methacrylate
monomer.
Can be used even if enamel is contaminated
with saliva or moisture.
Bond strength is similar to resin composite
adhesive

Adhesion Booster
• Used in cases of-Hypocalcified, fluorosed, and
deciduous enamel.
• Enhance adhesion booster was created to
increase adhesion and strength.
• Enamel pretreatment is done by the same
procedure.
• Part A & Part B are mixed
• Applied in 4 coats
• Air dried
• Ready to be used with chemical, light or dual
cure

Improving orthodontic bonding to amalgam
Two cases were studied:
Surface was abraded with diamond bur
Appeared rough on visual inspection
Under SEM, periodic ridges and grooves
had fewer under cuts.
Aluminum oxide sand blasting with 50-µ
abrasive powder in a microetcher at
approximately 7 Kg/cm2 of air pressure for 3
sec from a distance of 10mm.
had a frosted appearance.
Under sem, irregular surface with multiple
under cuts observed.

Result:
Strongest bond to sandblasted amalgam in this
study were achieved with Superbond C&B, 4-
META.
The liner version of super bond C&B is marketed as
amalgam bond.
increasingly used for bonding amalgam restoration.
This prevents microleakage & microgaps
Reduces hyper sensitivity
Provides stronger amalgam - to - amalgam bonds.
Reduced the need for mechanical retention
Sandbasting the amalgam surface prior
Bonding produces higher mean bond strengths with
Concise than roughening with a diamond bur.www.indiandentalacademy.com

The recommended bracket bonding procedure (with any
adhesive) consists of the following steps:
1. Transfer
2. Positioning
3. Fitting
4. Removal of excess.
Bonding to premolars: Most difficult, facilitated if
these teeth are bonded without a lip expander
BONDING PROCEDURE

Indirect Bonding with Silicone Transfer Trays.
1. Take an impression and pour a stone model.
The model must be dry. It may be marked on
each tooth.
2. Select brackets for each tooth.
3. Apply water-soluable adhesive on each base
or tooth.
4. Position the brackets on the model. Reposition
if needed
5.Mix material according to the manufacturer’s
instructions. Press the putty onto the cemented
brackets. Form the tray allowing sufficient
thickness for strength.www.indiandentalacademy.com

7. Trim the silicone tray and mark the midline.
8. Prepare the patient’s teeth as for a direct
application.
9. Mix adhesive load it in a syringe and apply a
sufficient portion to the bonding bases.
11. Remove the tray after 10 minutes. The tray
may be cut longitudinally or transversely to
reduce the risk of bracket debonding when it is
peeled off.
12. Complete the bonding carefully, remove
excess adhesive . Use oval or tapered TC
bur,clean around each bracket. Also inspect
around the bracket pad for adhesive voids (from
too little adhesive, tray slide on the teeth or
delayed seating) and fill with a small mix of
adhesive if needed.

CURING

Based upon the polymerization
initiation mechanism.
* Chemically activated (Also termed
chemically cured, autocured or self-cured):
two-paste or one-paste
* Light-cured (also termed photocured)
* Dual-cured (Chemically activated and
light cured)
* Thermocured)
Classification of orthodontic adhesive systems:

TYPES OF ADHESIVES
1.Acrylic resin
-based
on MMC
monomer
and ultrafine
powder
2.Diacrylate resin
Eg.Orthomite,Genie
based
on acrylic modified
epoxy resin,Bowen’s
resin or bisGMA
Both exist in either filled or unfilled

Filled diacrylate resins of bisGMA have
best physical properties and are the
strongest adhesives for metal brackets
(eg,Concise,PhaseII)
While acrylic or combination resins have
been most successful with plastic bracket.
Failure rates are less with adhesives
containing larger filler particals.

The most widely used resin commonly
referred to as Bowen’s resin or bis GMA
(bispheonal A glycidyl dimenthacrylate),
was designed to improve bond strength
and increase dimensional stability by
cross-linking.

NEW INNOVATIVES ARE-
1.No-mix adhesives: (eg,Rely-a-Bond)
set when one paste under light pressure
is brought together with a primer fluid on the
etched enamel
After positioning, press bracket firmly
into place and curing occurs within 30-60 sec.
Disadvantage is toxic .

These materials (Transbond) cured by
transmitting light through tooth structure
and ceramic brackets .
Argon lazer may be used for polymerization.
With metal brackets,usually dualsure resins
is used.
Bond strength is reported to be comparable
to chemically cured composites.
Fluoride-releasing visible light cureing
adhesives are also available.
2.Visible-light polymerized adhesives

LIGHT CURED
Light-cure is used to initiate polymerization
and this depends upon several factors-
-the exposure time,
-the photoinitiator concentration
-the light intensity emitted by the curing
unit and the filler volume

CURING LIGHT:
Due to demand to cure light - cure
adhesives quickly several new fast
cure light devices have been
introduced.
Laser
Cures adhesive in 5 sec, because
the photons that activate 
Adhesive catalyst released in a
collimated beam that concentrates a
larger number of photons.www.indiandentalacademy.com

Plasme Arc:
Camphorquinone, the most popular catalyst
used in light cure adhesives, optimally cures
at a wave length of 460 nanometers.
Standard curing light emitts 400-500 nanometer
.
The plasma arc light filters the wavelength to
440-480 and utilizes a higher watt bulb to
care standard composite in 10 sec.

Turbo tip: This simply reduces the
size of the director from 11mm to
8mm. As a result more energy
(photons) attacking the composite
beneath the bracket bars .
Curing time is 10 sec.

LED Curing light
• Features
• No heat build up
• No noise
• Long life(2000 hrs)
• Automatic self inspection
• Last operation in memory
• Sleeping device to save power
• Right and left hand usage
• Wave length-450~490nm

DUAL CURE
This approach combines the advantages of rapid
initiation for photo polymerizing resins and high
conversion rates for chemically cured resins.
Here polymerization is induced through surface
exposure by visible light, and in bulk material
occurs by a chemical process.
Hence, both improved surface and bulk material
properties would be expected.
In a study, this has significantly higher bond
strength then chemical or light cure.

Ceramic brackets.
Ceramic brackets bonds to enamel by
(1)mechanical retention and
(2)Chemical bonding by means of a
silane coupling agent.

Bonding on plastic brackets
This are typically polycarbonate,although some
are reinforced fiber-glass or metal.
Bonding is typically mechanical and is achieved
by swelling the base, for adhesive penetration.
The primer is methyl methylacrylate monomer
is used to cause the swelling.

With mechanical retention the stress of
debonding is generally at the adhesive-
bracket interface whereas the chemical
bonding may produce excessive bond
enamel-adhesive interface. Both
chemically cured and light-cure adhesives
are useful for ceramic brackets.

BOND STRENGTH

Typically performed in shear or tension, using a screw-driven
or servohydraulic universal testing machine

EFFECTS OF IMPORTANT
VARIABLES ON BOND
STRENGTH

Differences among teeth
Older permanent teeth tend to produce
slightly higher bond strength than younger
permanent teeth.

Sound Enamel :
Enamel is characterized by -mineral content
96wt%) and organic matter (0.4-0.8 wt%)
and water (3.2-3.6wt%).
The mineral phase is calcium hydroxyapatite,
known as appetites.
The tightly packed, hexagonal, needle-
shaped crystallites of the inter-prismatic
area, the crystallites are more randomly
oriented and loosely packed,

In deciduous enamel than in permanent
enamel.Which may be one factor why
lesion progression in deciduous enamel is
faster than in permanent enamel.
Macroscopically, and in the SEM, surface
enamel of newly erupted teeth exhibits the
so-called perikymata or imbrication lines.
Perikymata are thus rare in adults.
Orthodontic brackets contribute to loss of
the perikymata.

Effects of fluoride
Fluorosis is revealed as a diffuse
bilateral white opacity that cover the
enamel.
Long time ingestion accentuates the
appearance of the perikymata and is
associated with changes in color,
depending on dose, timing, and
duration of fluoride ingestion.

Surface enamel fluorsis differs from
non-fluoride-induced opacities, which are
generally well demarcated and
asymmetrically distributed, more resistant
to acid etching than normal teeth.
Fluorotic teeth, have about 40%
lower bond strengths than to normal
teeth, although a group of mildly to
moderately fluorotic teeth from young
adults showed similar bond strengths when
compared to normal teeth.www.indiandentalacademy.com

Bleaching
Recently bleached teeth have
significantly lower bond strengths to resin
composites. The bleach produces oxygen,
which inhibits free radical polymerization of
resin composites.
Measurements of debonding force and bond
strength
This plays an important role in characterizing
the bonding potential role in characterizing the
boding potential of new systemswww.indiandentalacademy.com

The filler content of resin composite affects
the bond strength .
Highly filled resin composite bond better to
metal bracket .
Hybrid
GIC have bond strengths lower than
resin composite

Retention of adhesives to ceramic brackets
can be mechanical or chemical or both.
Mechanical bonding requires indentations or
roughness caused by chemical etching with a
9.6% hydrofluoric
Chemical bonding requires treatment with
silane. One end of the silane molecule bonds to
the ceramic, while the other end bonds to the
carbon -carbon double bonds available from the
resin composite adhesive.

• Harder then steel, causes enamel wear of
the opposing tooth
• Difficult to debond
• Surface is rougher, attracts plaque and
stain more easily.
• Brittle in nature.

Coupling Agent
• The coupling agent –
methacrylpropyltrimethoxysilane(MPTS) is
widely used for promoting chemical adhesion
• Bonding arises from two mechanism-
1.Silanol groups of the hydrolyzed silane
adhere to the hydration layer of the inorganic
surface,
2.Methacrylate groups of silane copolymerize
with the methacrylate resin matrix, possibly
forming covalent bonds.

comparison of relative properties of cements
and adhesives used for orthodontic bonding
and banding.
CEMENT/ADHES
IVE
BOND STRENGTH
TO ENAMEL
BOND STRENGTH
TO METAL
BRACKETS
Resin composite
(Transbond)
High Medium -high
Hybrid ionomer
(Fuji ortho LC)
Medium -high Low-medium

Bond strength (MPa)
Adhesive Ceramic bracket Metal bracket Plastic bracket
Resin composite, highly filled 5 13 8
Resin composite, slightly filled 5 9 8
Hybrid ionomer 6-7 3-4 1-4

Bond strength (MPa)
Treatment
Mesh
base
Photo-
etched
base
Grooved
base
No treatment 8 8 9
Silanation 11 9 9
Etching 8 8 15
Activation 9 9 10
Etching and
silanation
10 8 11
Etching and
activation
8 8 12

In vitro ensile bond strengths of chemically
cured and paste-primer resin composite
orthodontic adhesives as a function of thickness
(mm) between the bracket and substrate.

BONDING TO DIFFERENT
MATERIALS

Bonding to amalgam.
Modification of the metal surface
(sandblasting, diamond bur roughening)
The use of intermediate resigns that improve
bond strengths( eg., all Bond 2, Enhance
Metal Primer) and
New adhesive resins that bond chemically to
nonprecious as well as precious metals
(e.g..,4-META resins, 10-MDP bis GMA
resins

The procedure recommended for bonding to
amalgam :
A.Small amalgam filling with surrounding sound
enamel :
1.Sandblast the amalgam for 3 seconds
2. Condition surrounding enamel with 37%
phosphoric acid for 15 to 30 seconds.
3.Apply sealant and bond with Concise or
similar composite resin

B. Large amalgam restoration or
amalgam only
1.Sandblast the amalgam
2. Apply a uniform coat of Reliance Metal
primer
and wait for 30 seconds
3. Apply sealant and bond with Concise or
similar,
composite resin.

Bonding to Gold
The procedure followed here is different .
1.Roughening the gold surface with green stone
and then use highly filled resin to increase the
bond strength.
2.Intraoral Sandblasting
3.Tin plating-By Sn deposition eletrolytically on
gold
-Plating with gallium-tin-solution
Better bond

• But actually.sandblasting
• coulped with use of All-Bond 2 or 4-META
primers followed by bonding with Concise or
metal bonding adhesives(MCP-bond,Superbond
C&B) did not bring satisfactory result.
• Adhesive that bond chemically to metal-
• 4 META(methacryloxy
ethyl trimellitate anhydrate)
• 10 MDP (methacryoxy
decyl dihydrogen phosphate)

Bonding to porcelain.
For optimal bonding of orthodontic brackets and
retainer wires to porcelain surfaces, the following
technique is recommended
1. Isolate the working field
2. Deglaze an area by sandblasting with 50 µm
aluminum oxide for 3 seconds.
3. Etch the porcelain with 9.6% HF acid gel for 2
minutes.
4. Carefully remove the gel with Cotton roll then rinse.
5.Immediately dry and bond with highly filled bisGMA
resin

BOND FAILURES

Possible causes of adhesive -enamel bond
failures (Adhesive left on bracket, little left
on tooth)
* Contamination.
* Insufficient rinsing of etchant .
* Inadequate drying of enamel surface
precludes penetration of resin.
* Over -etching demineralizes enamel,
reduces depth of resin tags penetration,

•Faulty bonding materials are unlikely, but
exparation dates should e checked and care
taken in handling of materials.
•
•No activator was placed on enamel surface
when a no-mix adhesive was used.
•
* Tooth surface required special preparation
because of amalgam, gold ceramic, or other
restorative material.

Possible causes of adhesive-bracket bond
failures (Adhesive left on tooth, little left on
bracket)
* Excessive force exerted on bracket from
occlusion or appliance.
* Movement of bracket during initial setting .
* Contaminated bracket mesh
* Adhesive not buttered into base firmly
* Activator not placed on bracket in paste-primer
system.
* Inadequate cure of light-cured resin composite
* special primer required (plastic brackets)www.indiandentalacademy.com

DEBONDING

Debonding Force
In units Newton's (N), kilograms (kg), or
pounds (lb). Bond strength, which is the force
of debonding divided by the area of the bonded
interface, strength in units of megapascals
grams per square centimeter.
An adhesive-bracket system should be able
to withstand a stress of at least 6-8MPa
mixture of adhesive and cohesive failures.

DEBONDING
Recycling or rebonding of metal brackets generally results
in lower bond strength.Sandblastig however produces
satisfactory bond strength.
Mechanical debonding of ceramic brackets can be
accomplished bb 3 ways-
1.Lift-off debonding instrument(LODI)
2.Delaminating method,here sharp-edged instrument.Force
application produces a peeling or wedge effect.
3.Employs a special tool that produces a torsional or
wrenching force at the base of bracket.

Bracket removal-steel brackets
Debracketing with pliers( twin beaked)cut
the brackets off between the tooth and the
base.
Another technique is to squeeze the
brackets wings mesiodistally

Amount of enamel lost in
debonding
The amt is related to several factors-
An initial prophylaxis with bristle brush for 10-15 sec abrade
as much as 10.
Whereas,with rubber cups only 5
Cleanup of unfilled resin with hand only results in a loss of
5-8
Removal of filled resin requires rotary inst, loss may then be
10-25.
High speed bur and green rubber wheel removes appro. 20.
But with careful use of TC bur,enamel loss was only 7.5www.indiandentalacademy.com

Enamel tearouts
Localized enamel tearouts is associated with
both metal and ceramic brackets
Microfilled causes more loss then macrofilled
resins
Unfilled resins have no such break points.
Clinical Implication is-
1.Use brackets that have mechanical
retention,such that during debonding,leave all
or majority of composite on the tooth.
2.Avoid scraping with hand instrument

Debonding on Porcelain
A gentle technique is necessary to achieve
failure at bracket-adhesive interface.
A 45 degreeperipheral force should be applied to
the tie wings or the wings should be squeezed.

Laser Debonding of Ceramic
Brackets
• Using both-Nd:YAG
-Co2
Initiated by applying a torquing force.
Debonding mechanism was thermal softening of resin
adhesive.
Temperature rise was transmitted through the bracket
Debonding time was 3-4 sec.
No carbon deposit,enamel tear or bracket fracture was
observed.

Removal of residual adhesive
• Because of colour similarity between present
adhesives and enamel,complete removal is
not easily achieved.
This is achieved by,
1.Scraping with a very sharp instrument,
2.With a TC bur.

Recycling
Main goal is to remove the adhesive
without damaging or weakening the
bracket.
Procedure-
Heat to burn off the resin
Electropolishing to remove the oxide
build
By Sandblasting.
Use of TC burs to remove the
composite.

Prompt L-Pop
Introduced in 1999 (All-in-one system)
Comes in a blister foil that contains 3
compartments
1st
compartment-methacrylated phosphoric acid
esters,photoinitiators,stablizers.
2nd
compartment-water,complex
fluride,stabilizers.
3rd
–containing the microbrush

Blister is activated by squeezing
comp1,releasing its content into comp2.
Mixing ratio is 4:1,and by squeezing comp2
releases mixed solution on the microbrush

Finishing

CONCLUSION
PRODUCT DEVELOPMENT AND
IMPROVEMENT HAS IMPROVED
DRASTICALLY SINCE THE EARLY 1970’S
.MOST OF THE PROBLEMS ASSOCIATED
WITH BONDING TECHNIQUES HAVE FADED
AWAY.
TODAY WE HAVE VERY LITTLE TO
BE CONCERNED ABOUT;EXCEPT
OURSELVES.

References:
1.Graber Varnasdal
2.Mc Namara , Brudon
3.Proffit

THANK YOU

Bonding aftab

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