Debanding , debonding and removal of

orthodontic composite remnants .

prof. dr. Maher Fouda

Faculty of Dentistry. Mansoura university

Mansoura .Egypt

The objectives of debonding

Is to Remove the attachments and all the adhesives from the teeth.

Is to restore the surfaces of the teeth as closely as possible to their pretreatment condition without inducing iatrogenic damages to the enamel surfaces.

Debonding is discussed in

detail as follows;Clinical procedure.

Enamel tear outs and cracks(fractures lines).

Removal of the residual adhesives.

Amount of enamel lost in debonding.

Operator safety during debonding.

Clinical procedureRemoval of steel brackets;

The brackets should be individually removed to avoid the force transfer from tooth to tooth, which may increase risk of enamel crack formation.

With metal brackets, applying a cutting pliers to the base of the bracket so that the bracket bends is the safest method. This has the disadvantage of destroying the bracket, which otherwise could be reused, but protecting the enamel usually is a more important consideration

1. Mechanical Methods: Using pliers (bracket removing plier, Howe plier, ligature cutter, Weingart)or wrenches.

The original method:

Place a tips of a twin-beaked pliers against

the mesial and the distal edges of the bonding

base and cut the brackets off between the tooth

and the base.

Gentler technique:Squeeze the bracket wings mesiodistally and

then lift the bracket off with a peel force.

This technique is useful on mobile, brittle

or endodontically treated tooth..

The recommended technique,

in which brackets are not deformed and is to

remove the brackets while it is still ligated

in place.

The brackets are gripped one by one

with bracket-removing plier

and

lifted outward at a 45-degree angle. The indention

In the pliers fits into the gingival tie-wings for

a secure grasp

Lift-Off Bracket Remover

Place the wire over any bracket wing, position the instrument so that

it is over the bracket, gently squeeze the handle until the two contact

surfaces are balanced over the tooth and squeeze more until the

bracket lifts from the tooth

This technique is quick and gentle and leave

the brackets intact and fit for recycling.

The bond breaks in the adhesive bracket interface

and the pattern of the mesh backing is visible on

the adhesive remaining on the tooth.

This technique uses a peeling type force.

A peel force ,as in peeling an orange, creates prepheral stress

concentrations that cause bonded metal brackets

to fail at low force values.

.

Attempts to remove the brackets by shearing it off

( as is done in removing the bands)can be traumatic to the patient

and damaging to the enamel

Task Bond Removing Pliers

Designed to remove excess composite bond

from the enamel surface after debonding.

The plastic tip sits on the occlusal surface, whilst

the metal tip gently removes adhesive residue.

Task Bracket Removing Pliers

Designed to remove any type of direct

bond bracket – metal, ceramic or

composite.

The blades slide behind the base of the

attachment, and when squeezed, lift it

from the tooth surface.

.

Task Bracket Remover Angled Task Bracket Remover Straight

Mesiodistally cutting off the brackets with gradual pressure from the tips of twin-beaked pliers oriented close to the bracket–adhesive interface is not recommended because doing so may introduce horizontal enamel cracks.

2. Ultrasonic method using

special tips

Ultrasonic tip can cause cohesive

bond failure within the adhesive or

bond failure occurs at enamel adhesive interference. So bracket damage is

avoided.

it minimizes the potential for bracket failure as well as the trauma to the enamel surface during debonding .

3-Electro-thermal Method:

Overcomes the problems of bracket failure, enamel damage and high forces when debonding orthodontic brackets. The electro thermal debracketing instrument transfers heat through the bracket, allowing bond failure at the bracket-adhesive interface as the heat deforms the adhesive.

Removal of ceramic bracketsDebonding of the ceramic brackets is more liable to enamel

fracture formation since they more strongly adhere to the enamel surface and will not flex when squeezed with debonding pliers.

Recent ceramic brackets have a mechanical lock base and a vertical slot that will collapse the bracket by squeezing. Debonding collapsible ceramic brackets with the arch wire in place and ligated to hold together the debonded bracket parts is recommended.

Ceramic brackets bond to enamel by

indentations and/or undercuts in the

base (mechanical retention)

Chemical retention of

a ceramic bracket

base.Fracture of two tie-wings.

Ceramic brackets are a particular problem for debonding because their base cannot be distorted. They break before they bend. There are two ways to create adhesion between a ceramic bracket and the bonding adhesive: mechanical retention through undercuts on the bracket base, as is done with metal brackets, or chemical bonding between the adhesive and a treated bracket base.

The mesh design closely replicates a metal base, while the

polymer material provides a protective barrier between the

ceramic bracket and the enamel. Since the base flexes upon

debonding, the bracket removes cleanly without the need to

fracture the bracket or rely on special tools

Chemical retention

of a ceramic bracket

base

It is quite possible to create such a strong bond between the adhesive and a chemically treated bracket base that failure will not occur there, but then when the bracket is removed, there is a real chance of enamel surface damage. Reports of enamel damage on debonding began to appear soon after ceramic brackets were introduced and have been a problem ever since.

Enamel damage from debonding metal brackets is rare, but there have been a number of reports of enamel fractures and removal of chunks of enamel when ceramic brackets are debonded . It also is easy to fracture a ceramic bracket while attempting to remove it, and if that happens, large pieces of the bracket must be ground away with a diamond stone in a handpiece.

These problems arise because ceramic brackets have little or no ability to deform—they are either intact or broken. Shearing stresses are applied to the bracket to remove it, and the necessary force can become alarmingly large

There are three approaches to these problems in debonding ceramic brackets: 1. Modify the interface between the bracket and the bonding resin to increase the chance that when force is applied, the failure will occur between the bracket

and the bonding material.

Most of the ceramic brackets now on the market have an interface designed to make removal easier. Chemical bonds between the bonding resin and the bracket can be too good, and most manufacturers now have weakened them or abandoned chemical bonding altogether.

2. Use heat to soften the bonding resin, so that the bracket can be removed with lower force. 3. Modify the bracket so that it breaks predictably when debonding force is applied.

Nevertheless, the ideal solution would be to perfect the third approach-modification of the bracket -so that ceramic brackets can be debonded without heating as readily as metal ones.

One advantage of a metal slot in a ceramic bracket is that then the bracket can be engineered to fracture in the slot area, which makes it much easier to remove.

Electrothermal and laser instruments to heat ceramic brackets for removal now are available. There is no doubt that less force is needed when the bracket is heated, and research findings indicate that there is little patient discomfort and minimal risk of pulpal damage.

The Pauls Tool

The QuicKlear bracket is by far the easiest ceramic bracket to

remove. The Pauls Tool fits over the bracket and a simple push or

pull on the handle toward the tooth or away from the tooth will easily

debond the bracket.

The Pauls Tool disengages the bracket from the tooth. No pain!

No noise! No squinting of patient’s eyes! The bracket is removed

in one piece and during treatment, if desired the bracket can be

removed and replaced to a better position on the tooth surface

Easier and safer way for sapphire bracket de-bonding process• Produced the highest quality, corrosion resistant stainless steel.• Prevent the fracture on bracket.• Possible to remove the bracket even with the ligation of wire.• Provide easier and comfortable handling for users.• Able to use with other bracket brands

Sapphire Bracket Orthodontic De-bonding pliers Aesthetic

Transparent Clear

De-bonds like metal using “Wrench” debonding

instrument in combination with advanced mechanical

mushroom-style base

• Wrenching method: ceramic brackets are debonded

by a special tool that uses a torsional or wrenching

force at the base of the bracket

Grinding

Low-speed grinding of ceramic brackets with no water coolant may cause permanent damage or necrosis of dental pulps. Therefore water cooling of the grinding sites is necessary.

Lasers

also have the potential to be less traumatic and less risky for enamel damage. This procedure first appeared to facilitate the removal of porcelain laminate veneers, which are bonded using a very strong resin cement. Öztoprak and colleagues demonstrated that with a new scanning method, the Er:YAG laser is effective for reducing SBS of ceramic brackets from high values to levels for safe removal from the teeth in 9 seconds per bracket.

Additionally, in a recent study, Mundethu and co-workers reported that clear brackets can be debonded with a single pulse when irradiated with the Er:YAG laser operating at 600 mJ, 800-μs pulse, 1.3-mm fiber tip. With this method, 19 out of 20 brackets successfully debonded with a single pulse

In this method, laser energy is transferred through the ceramic and absorbed at the composite layer where micro explosions occur, resulting in the detachment of the bracket without any thermal damage to the tooth.

The laser tip is brought into contact with the ceramic bracket

and initiated for

laser-aided debonding. Laser energy is transferred through the

ceramic and absorbed at the composite

layer where microexplosions occur, resulting in the detachment

of the bracket without any

thermal damage to the tooth.

Enamel Tearouts and Cracks (Fracture Lines)

Localized enamel tearouts have been reported to occur associated with bonding and debonding metal and ceramic brackets.

Ceramic brackets using chemical retention cause enamel damage more often than those using mechanical retention.

This damage probably occurs because the location of the bond breakage is at the enamel–adhesive interface rather than at the adhesive–bracket interface.

the sharp sound sometimes heard on the removal of bonded orthodontic brackets with pliers is possibly associated with the creation of enamel cracks.

Hosein et al pointed out that more surface enamel is lost during debonding and clean-up procedures than during bonding. Least enamel was lost during clean-up of brackets bonded with a self-etching primer system compared to conventional acid-etching technique.

With ceramic brackets, the risk for creating enamel cracks is greater than for metal brackets. The lack of ductility may generate stress in the adhesive–enamel interface that may produce enamel cracks at debonding.

Clinical implicationUse brackets that have mechanical retention and debonding instruments and techniques that primarily leave all or the majority of composite on the tooth

Avoid scraping away adhesive remnants with hand instruments.

Another important clinical implication may be the need for a pretreatment examination of cracks, notifying the patient and the parents if pronounced cracks are present.

Removal of bands is accomplished by breaking the cement attachment and then lifting the band off the tooth, which sounds simpler than it is in some instances. For upper molar and premolar teeth, a band-removing instrument is placed so that first the lingual, then the buccal surface is elevated .

Bands are largely retained by the elasticity of the band material as it fits around the tooth. This is augmented by the cement that seals between the band and the tooth, but a band retained only by cement was not fitted tightly enough.

Maxillary right

first molar, mesial

aspect. LR,

Lingual root; FC,

fifth cusp; MLC,

mesiolingual

cusp; MMR,

mesial marginal

ridge; MBC,

mesiobuccal

ridge; MCA,

mesial contact

area; CR, cervical

ridge; MBR, mesiobuccal root

Mandibular right first

molar, mesial aspect.

MMR, Mesial marginal

ridge; MLC,

mesiolingual cusp;

MCA, mesial contact

area; CL, cervical

line; DD,

developmental

depression; CR,

cervical ridge; MBC, mesiobuccal cusp

Cement left on the teeth after debanding can be removed easily by scaling .

No orthodontic band cement bonds strongly to enamel (which is why band cements cannot be used to bond brackets). When the band is distorted by force to remove it, the cement breaks away from the band or the tooth, and there is almost no chance of damaging the enamel surface

Removal of composite

remnants after bracket debonding.

It is as important to remove a fixed appliance safely as to place it properly.

Acid etching removes approximately 10 µm of enamel

surface and creates a morphologically porous layer (5

µm to 50 µm deep). The low-viscosity fluid resin

contacts the surface and is attracted to the interior of

these microporosities created by capillary attraction.

Resin tags are formed into microporosities of

conditioned enamel that after adequate

polymerization, provide a resistant, long- lasting bond

by micromechanical interlocking with this tissue .

50µ= 0.05000000mm

5µ= 0.005000000mm

10µ= 0.01000000mm

penetration depth of the etching acid into the tissue ranging from 5 to 50 𝜇m.

5µ= 0.005000000mm 50µ= 0.05000000mm

Debonding of brackets usually leaves a residual adhesive volume of 0.6 to 2.5 mm on the enamel surface .

. Factors which are affecting acid etching of

enamel include: 1. Type of the acid 2. Concentration of

the acid 3. The time of etching. Etching with 10 % or 37 %

phosphoric acid produces the highest bond strengths to

enamel. The use of 10 % maleic acid for etching results in a

lower bond strength . No etching yields a very low bond

strength. No differences in bond strengths are observed

when enamel is etched with phosphoric acid ranging in

concentration from 2 % to 37 % .

Iatrogenic Effects of Etching: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 about 10 ±20 µm of

enamel.5. Resin tags retained in enamel - possible

discoloration of resin.6. Rougher surface if over-

etched .

Duration of Etching . No differences in bond

strength are detected between 15-second and 60-

second etching with 37 % phosphoric acid;

however, shorter etching times cause less enamel

damage on debonding. Decreasing etching time

between 30 and 10 seconds does not affect bond

strength(11 Mpa) or location of failure site

Whereas etching for 0 or 5 seconds reduces bond

strength (less than 3 Mpa).

the application of a sustained force

during the bonding process affects

the adhesive layer and improves the

bond strength mainly because it

reduces fluid interference from the

underlying dentine (Chieffi et al.,

2006, 2007; Goracci et al., 2006).

When enamel etching was introduced in 1955,

the recommended time was 30 seconds for 85% phosphoric acid. Then, at the time of its first clinical use (the 1960s), it was extended to 60 seconds. In the 1980s, it was reduced to a 30-second application and has remained today .

Enamel Acid Etching: C A Review

January 2007;28(1):662-669

Some authors recommend reducing the etching time to 15 seconds when a 32% to 40% phosphoric acid is used. Most of the manufacturers of adhesive systems have recommended 15 seconds because it saves time without compromising the adhesive performance.

Enamel Acid Etching: C A Review

January 2007;28(1):662-669

As a result, it has been suggested that the conditioning time be reduced to 15 seconds, which is considered adequate for creating a retentive enamel surface with no difference in the enamel etching pattern or decrease of the bond strengths. . In vitro studies have demonstrated that a 15-second conditioning time is also adequate for orthodontic adhesive procedures. The third advantage is saving chair time.

Enamel Acid Etching: C A Review

January 2007;28(1):662-669

A 15-second etching time is sufficient when using 32% to 40% phosphoric acid to achieve a proper bond strength when it is applied to instrumented enamel surfaces or when a cavitary preparation has been accomplished.

Enamel Acid Etching: C A Review

January 2007;28(1):662-669

Reducing times has been suggested because it presents 3 advantages. First, because acid conditioning causes superficial tissue loss, it is desirable that minimal tooth structure be dissolved; therefore, minimal acid-application time should be used. The difference between 15-second and 30-second application time of phosphoric acid on enamel dissolution is very small. The chemical reaction of the conditioning occurs quickly and, as mineral components are lost, the acid potential decreases by buffering.

Enamel Acid Etching: C A Review

January 2007;28(1):662-669

AFM ANALYSIS OF ENAMEL DAMAGE DUE TO ETCHING WITH ORTHOPHOSPHORIC ACID

. The surface of enamel after laying the phosphoric acid was demineralized in a 5−10 μm layer, which is the area of etched enamel. The pores about 20 μm thick are created beneath the surface, and these are the areas of qualitative pores, while beneath that area there is the area of quantitative pores, about 20 μm thick.

20 micron

0.02 mm

With improvements in the physical and mechanical properties

of resin adhesive systems, cleanup of resin remnants

after orthodontic bracket debonding has

become a clinical problem.

Pocket Dentistry

Fastest Clinical Dentistry Insight

Engine

Adhesives and Bonding in Orthodontics

The removal of adhesive remnants from tooth

surfaces is a final procedure to restore the

surface as closely as possible to its

pretreatment gloss without inducing iatrogenic

damage

If remnants are not completely removed,

tooth surfaces are likely to discolor and

entrap plaque .

Despite the introduction of new methods (e.g., Nd:YAG

laser) to remove residues of bonding resin selectively, the

most common removal techniques use a low-speed

handpiece with a tungsten-carbide bur and a high-

speed handpiece with a diamond bur. The preferred

method uses a low-speed handpiece with a round,

tungsten-carbide bur.

tungsten-carbide bur diamond bur

The bulk of the remaining adhesive may be removed

with diamond or tungsten-carbide burs

attached to a high-speed handpiece.

Because of considerable scratching,

however, these should not be used closer

to the enamel surface.

When approaching the enamel, a tungsten-carbide

bur attached to a low-speed hand piece operating at

30,000 rpm should be used. For this purpose, the

bur is moved in one direction as the resin layers are

removed. Water cooling is avoided at this stage

to improve the contrast between the adhesive and

the enamel surface.

The mechanics of high-speed rotary

instrument. A, The blue circular arrow indicates that the high-

speed diamond bur rotates in a clockwise direction when viewed

from the head of the handpiece. The green arrows indicate the

direction that the instrument should be drawn to counteract the

rotational force of the bur and achieve the most rapid abrasive

action of the bur.

B, Incisal view of the forces generated during high-speed rotary tooth

preparation. As the bur rotates in a clockwise direction, it generates a

rotational force at the tooth surface, FB(large blue arrow that represents

schematically the force of tooth structure against the bur). The operator

of the instrument must generate an opposing force, Fo (green arrow),

which will exceed the rotational force of the bur, FB, and carry the instrument against the tooth surface where the surface will be abraded

Any recontouring considered necessary should be

completed at this stage before proceeding to polishing

The brackets were removed, and then, with the aid of a UV

light source , the cement adhering to the enamel was removed selectively.

ORTHOCEM UV TRACE

Orthocem UV Trace contains a fluorescent tracer, which in contact with ultraviolet light, emits an blue light, facilitating its removal at end of the treatment.

• 1 syringe with 4g

• 1 acid conditioner (Condac 37 – FGM)

Orthocem UV Trace is a light-curing cement for

the bonding of orthodontic brackets made of

polycarbonate, metal and ceramic, which has a

difference to the already known Orthocem: the

inclusion of a fluorescent tracer. When it

receives UV (ultraviolet) energy originating from

specific equipment at a determined wavelength,

the cement emits a bright blue light

(fluorescent) that allows it to be distinguished

from the enamel.

UV Tracer: when UV light is applied, it enables cement

residues stuck to the enamel to be identified.

• Photo-activated curing mechanism: enables control

of the working time when placing the material.

• Balanced adhesive strength: balanced adhesion to

avoid adhesive failure measured throughout treatment

as well as facilitating removal of the bracket at the end

of treatment.

Appropriate consistency: facilitates the installation

of the brackets.

• Comprehensive application spectrum: cements

various types of brackets (polycarbonate, metal or

ceramic).

•High aesthetic quality: resistant to color

variations over time and with high translucency;

• Greater practicality: primer and bond in the same

syringe; reduction in clinical steps.• Light curing:

Operator Safety During Debonding

Another important but often ignored issue is the

inhalation of aerosols produced during the removal of

fixed orthodontic appliances. Recent research shows that

aerosol particulates produced during enamel cleanup

might be inhaled regardless of handpiece speed or the

presence or absence of water coolant.

This aerosol may contain calcium,

phosphorus, silica, aluminum,

iron, and lanthanum.

Although the particles most likely are deposited in

the conducting airways and terminal bronchi,

some might be deposited in the terminal alveoli of

the lungs and cleared only after weeks or months.

Studies indicate that

orthodontists are exposed to high

levels of aerosol generation and

contamination during the

debonding procedure, and that

preprocedural chlorhexidine

gluconate mouthrinse appears to

be ineffective in decreasing

exposure to infectious agents.

Barrier equipment should be used

to prevent aerosol contamination.

Detailing and Polishing

After completion of adhesive removal, the enamel

surface may be further polished using various soft

disks, cups, and pastes. Some authors view this

stage as “optional,” considering the normal wear of

enamel.

The wide diversity of elastomeric or

rubberized abrasive rotary finishing

and polishing devices. Coarser

finishing and pre-polishing devices

are on the top row; polishing

devices are aligned on the lower row

of the illustration.

Synthetic and natural foam or felted polishing paste

rotary applicators provide for a more efficacious and

efficient final polishing step using loose-abrasive

polishing pastes. Synthetic and natural felt applicators

appear on the left and center of the photograph;

synthetic foam cup applicator appears on the far right

A recent technologic development in restorative

polishing involves abrasive-impregnated brushes,

which are depicted in this photograph. The three

abrasive brushes from left to right contain diamond

particles as the abrasive. The brush on the far right

contains silicon carbide

Newer rotary devices have broadened the range of

indications for finishing and polishing devices. The white,

fiber-impregnated polymer rotary burs have been suggested

and indicated for “minimally” abrasive action—that is, stain

removal and selective composite removal. The blue rotary

bur (right) is suggested for removal and cleaning of

temporary cement on tooth preparations before final

cementation

Bonded brackets must be removed, insofar as possible, without damaging the enamel surface. This is done by creating a fracture within the resin bonding material or between the bracket and the resin and then removing the residual resin from the enamel surface.

Complete removal of all remaining adhesive is not easily achieved because of the color similarity between present adhesives and enamel.

The greater strength of bonding adhesives becomes a potential problem in debonding. When a bonded bracket is removed, failure at one of three interfaces must occur:

between the bonding material and the bracket, within the bonding material itself, or between the bonding material and the enamel surface.

.

enamel surface as it pulls away from it

If a strong bond to the enamel has been achieved, which is the case with the modern materials, failure at the enamel surface on debonding is

undesirable because the bonding material may tear the

Enamel fracture at debond

The interface between the bonding material and the bracket is the usual and preferred site of failure when brackets are removed. The safest way to remove metal brackets is to distort the bracket base, which induces failure between it and the bonding adhesive. This damages the bracket so that it cannot bereused.

The major reason for not recycling and reusing brackets is the possibility of enamel damage when they are removed without distorting the base. If brackets can be

removed without damage they can be cleaned, sterilized, and reused without risk to the patient in exactly the same way as other medical devices

Residual bonding resin is more difficult to remove .The best results are btained with a 12-fluted carbide bur at moderate speeds in a dental handpiece . This bur cuts resin readily but has little effect on enamel.

Topical fluoride should be applied when the cleanup procedure has been completed, however, since some of the fluoride-rich outer enamel layer may be lost with even the most careful approach.

Many patients may be left with incomplete

resin removal, which is not acceptable.

Abrasive wear of present bonding resins is

limited and remnants are likely to become

unesthetically discolored with time .

The removal of excess adhesive may be

accomplished by 1. Scraping with a very sharp band or bond-removing pliers or with scaler.

As a final quality assurance check after debonding orthodontic

brackets. In this regard, following the removal of any

composite deposits using a tungsten carbide bur in a slow

hand-piece, the Mitchell's trimmer may be used to sweep up

and down the labial surface of the tooth, in order to detect any

missed adhesive remnants. This then shows up as silver grey

on the surface of any residual composite, thereby rendering

the task of the adhesive's complete removal.

Mitchell's trimmer

2. Using a suitable bur and contra –angle. -- Dome shaped

TC bur -- Ultrafine diamond bur -- White stone finishing bur.

Although the first method is fast and frequently successful

on curved teeth it is less useful on flat anterior teeth. Also, a

risk exists of creating significant scratch marks

TUNGSTEN CARBIDE

ORTHODONTIC

DEBONDING BURS

Ultrafine diamond bur

The removal of excess adhesive may be accomplished by

. Residual Adhesive Cleaning • Methods :

Use of handpiece with tungsten carbide

bur (30,000rpm) - High speed handpiece

with diamond bur - Scraping with sharp

band or bond removing pliers • Scarring of

enamel after debonding is inevitable •

Angle Orthodontist. 1995;65:103-110

Phillip M, Campbell. Enamel surfaces after orthodontic debonding

diamond bur

tungsten

carbide

bur

Tungsten carbide slow speed adhesive removal burs were found to be less damaging to the enamel surface compared with high speed tungsten carbide burs and abrasive discs.

Fine fluted tungsten carbide burs used

with high speed, with light brush stroke

in one direction is most fastest and

least damaging method .

Fine fluted(grooved) tungsten carbide burs

The fewer the flutes, the more aggressive is the cutting

tungsten carbide bur

Speeds higher than 30,000 rpm using fine fluted(rugged)

tungsten carbide burs may be useful for bulk removal

but are not indicated closer to the enamel because of

the risk of marring(HARM) the surface.

Remnants of adhesive on enamel surface can be also eliminated through different methods and instruments including:

• bioactive glass air abrasion

• aluminum oxide air abrasion :Compressed air shoots

a tiny stream of aluminum oxide particles and

water, and a small vacuum sucks up the materials.

The preferred method for the removal of

excess adhesive is to use a suitable

dome-tapered tungsten carbide bur

in a contra-angle hand

piece.

Clinical experience and laboratory studies indicate that approximately

30,000 rpm is the optimum for rapid adhesive removal without enamel damage.

Light painting movements of the bur should be used so as not to cause deep scratches on the enamel.

Water cooling should not be used when the last remnants are removed because water lessens the contrast with enamel.

When all adhesive has been removed, the

tooth surface may be polished with pumice

ultrafine highspeed diamonds produce considerable surface scratches. Slower speeds (10,000 rpm and less) are ineffective, and the increased jiggling vibration of the bur may be uncomfortable to the patient.

INFLUENCE ON ENAMEL BY DIFFERENT

DEBONDING INSTRUMENTS Zachrisson and Artun

were able to compare different instruments commonly

used in debonding procedures and rank their degrees

of surface marking on young permanent teeth.

The study demonstrated that 1. diamond instruments were

unacceptable; even fine diamond burs produced coarse

scratches and gave a deeply rough appearance. 2. medium

sandpaper disks and a green rubber wheel produced

similar scratches that could not be polished away

3. fine sandpaper disks produced several marked

and some even deeper scratches and a surface

appearance largely resembling that of adult teeth.

4. plain cut and spiral fluted TC burs operated

at about 25,000 rpm were the only instruments

that provided the satisfactory surface

appearance. 5.none of the instruments tested

left the virgin tooth surface with its perikymataintact.

The clinical implication of the study is that TC

burs produced the finest scratch pattern with

the least enamel loss and are superior in their

ability to reach difficult areas-pits, fissures,, and

along the gingival margin

Shofu tip is also used for the removal of the residual adhesives but it was reported that The Shofu tip at low speed or high speed promoted the highest surface roughness on enamel compared to debonding pliers, carbide bur at high speed, carbide bur at low speed

A – Shofu tip;

• Some patients complain about color change of their teeth during and after orthodontic treatment.

• the composite bur provided a smoother enamel surface than was produced by the

carbide bur.

STAINBUSTER burs (Pearson Dental Supply

Co., Sylmar, CA) gently remove cement, stains, and colored

coatings from the surface of the enamel without abrading tooth

enamel or ceramic. The burs are made up of the fiber sections

with abrasive power, which cover the entire working surface

and split up into small fragments as they act on a hard surface.

• A recent study confirms this and states that both the orthodontic adhesive systems and the burs used to remove their residuals on tooth surfaces are responsible for this effect.

• The authors suggest using STAINBUSTER burs (A new composite bur, reinforced by zircon-rich glass fiber) to remove the adhesive remnants close to the enamel surface.

Thus reducing the occurrence of bacterial colonization and decalcification

New composite burs for cement and stains removal gentle for enamel, ceramics, and soft tissues

. Removal of stains and coloured coatings . Cleaning of the enamel after ultrasonic scaling . Grinding of

composite fillings . Easy removal of surplus cement . Elimination of temporary cement

STAIN BUSTER (tseZlatneD) Stain Remover Burs

Cleanup with Super-Snap produced acceptable

results, but a number of deep scratches were left

on the enamel surfaces.

Manufacturer: Shofu Dental

Super-Snap is designed for easy, fast and safe contouring, finishing and polishing of all

microfilled and hybrid composites.

•Ultra-thin, colour coded discs indicate the grit and function to take you step-by-step to the

finest restorations you can achieve.

•Four different colour-coded and grit-sizes in both standard and mini-discs without metal

centres – giving protection against ditching or scoring-on composite or compomer restorations.

•For interproximal areas use polystrips which are matched to give the same finish as the discs.

Types: L506 (Black, Coarse Contour, Safeside Down), L508 (Dark Violet, Medium Finish,

Safeside Down), L509 (Light Violet, Medium Finish, Safeside Up),

L501 (Dark Green, Fine Polish, Double Sided), L502 (Dark Red, Extra-Fine Polish, Double

Sided)

Packing: Each kit contains 100 Standard Discs, 80 Mini Discs, 40 Polystrips, 2 Dura-White

Stones (Shapes CN1 & FL2), Composite Fine Midi-Point and 2 CA Mandrels. Each refill disc

pack contains 50 pieces

After removal of the adhesive, it should be followed by multistep Sof-Lex disks and pumice slurry because a negligible amount of resin ranging from 0.11 to 0.22 mm3 is left on the tooth surface, and the use of polishing systems with good composite polishing properties may leave a lustrous surface and therefore more composite remnants as they become invisible.

Polishing also can be done using;

One-Gloss silicone particle polishing alone produced

enamel surfaces that were closest to the intact enamel

surface, but the polishing efficiency was the lowest

between all the methods.

.

NOTEIn clinical settings, cooling procedures that use air-

water sprays are essential to ensure the prevention of pulpal damage

Removal of resin remnants with a tungsten carbide bur using a high-speed handpiece without water cooling produces temperature increases exceeding the critical 5.58°C value for pulpal health.

The removal of residual adhesive after debonding is best performed with fine burs.

Upon debonding , the bond failure usually occurs between the base of the bracket and the resin, leaving excess resin on the tooth. Removing excess bonding resin is best accomplished with a smooth 12-fluted carbide bur, followed by pumicing. The carbide bur is used with a gentle wiping motion to remove the resin.

Clean-up with water cooling never produces temperature changes exceeding the critical value. Temperature rise of 9.4°C was found using a 6-fluted bur, followed by the 12-fluted bur (6.5°C) and 1.2°C using a 40-fluted bur.

AMOUNT OF ENAMEL LOST IN DEBONDING 10 to 25 μm.

Pus and Way(AJO 1980) found a high-speed bur and

green rubber wheel removes approximately 20μm and a low- speed TC bur removes around 10μm of enamel..

. B, Tooth ground by a diamond bur. Note the multiple

scratches formed by the random arrangement of abrasive particles on the diamond bur.

Van Waes et al(1997) recently confirmed

observations of a more limited loss of enamel when TC

burs are used cautiously. They found an average

enamel loss of only 7.4 μm and concluded that minimal

enamel damage is associated with careful use of a TC bur for removal of residual composite

Tooth cut by a carbide bur. Note the regular pattern of removal of tooth structure, which corresponds to the regular arrangement of blades on the bur

ENAMEL TEAROUTS

ENAMEL TEAROUTS Redd TB(Jco1991)

suggested localized enamel tearouts have been

reported to occur associated with bonding and

debonding both metal and ceramic brackets. They

may be related to the type of filler particles in the

adhesive resin used for bonding and to the location

of bond breakage.

When comparisons were made between tooth

surface appearances after debonding metal

brackets attached with either macrofilled (10 to

30μm) or microfilled (0.2 to 0.3μm) adhesives, a

difference occurred when the resin was scrapped

off with pliers

On debonding the small fillers reinforce the

adhesive tags. The macrofillers, on the other hand,

create a more natural breakup-point in the enamel-

adhesive interface. Similarly, with unfilled resins

there is no natural breakpoint.

The clinical implications is 1. To use

brackets that have mechanical retention and

debonding instruments and techniques that

primarily leave all or the majority of composite

on the tooth. To avoid scraping away adhesive

remnants with hand instrument

ENAMEL CRACKS Zachrisson BU et al (AJO

1980) The prevalance of cracks, their distribution per

tooth, their location on the tooth surface and the type

were described; 1. Vertical cracks are common, but

great individual variation

Few horizontal and oblique cracks are observed normally. 3.

No significant difference exists between the three groups with

regard to prevalance and location of cracks. 4. The most

notable cracks are on the maxillary central incisors and canines

The clinical implication of these findings 1. observes

several distinct enamel cracks on the patients teeth

after debonding, particularly on teeth other than

maxillary canines and central incisors 2. detects

cracks in horizontal direction, this is an indication

that the bonding or debonding technique used may

need improvement. With ceramic brackets, the risk

for creating enamel cracks is greater than for metal

brackets. The lack of ductility may generate stress

build-up in the adhesive-enamel interface that may

produce enamel cracks at debonding

The reason for this examination is

that patients may be overly inspective

after appliance removal

and may detect cracks that

were present before

treatment of which they

were unaware. They may

question the orthodontist

about the cause of the

cracks.

Enamel cracks generally are not visible on

intraoral photographs. Several cracks

are clearly seen on the left central incisor with

fiberoptic transillumination (A) and are

undetectable

by routine photography (B).

Note

The prevalence of enamel cracks after debonding has been found as high as 50%, with vertical cracks being the most common.

Without a pretreatment

diagnosis and documentation

(most cracks are not visible on

routine intraoral slides), proving

that such cracks are indeed unrelated

to the orthodontic treatmentis almost impossible.

ADHESIVE REMNANT WEAR Adhesive has been

found on the tooth surface, even after attempts to

remove it with mechanical instruments. Because

of color resemblance to the teeth, particularly when

wet, residual adhesive may easily remain

undetected.

Brobakken and Zachrisson (AJO 1981) Abrasive

wear depends on the size, type and amount of

reinforcing fillers in the adhesive. At the time of

debonding, varying amounts of adhesive were

purposely left on the teeth assumed to be the most

exposed to tooth brushing forces. Only thin films

of residual adhesive showed any reduction in size

ADHESIVE “ is a material frequently a viscous fluid that joins two

surfaces together and solidifies and therefore is able to transfer a

load from one surface to the other.

2 basic types resins for orthodontic bonding 1- Acrylic

/ Based on Self-curing acrylics / Methylmethacrylate

monomer & ultra fine powder / form linear polymers

only / filled or unfilled forms / e.g Orthomite, Genie /

Plastic brackets 2-Diacrylate resin based on acrylic

modified Epoxy resin / Bis GMA or Bowen’s resin /

Polymerised also by cross linking into 3 dimensional

network / Cross linking – greater strength / filled or

unfilled forms / e. g Concise, Phase II .

COMPOSITES RESINS FILLERS Bis-GMA / URETHANE-

DIMETHACRYLATE TEGMA-REDUCES VISCOSITY QUARTZ

FUSED SILICA ALUMINO- SILICATES BARIUM OXIDES

Coupling agent: vinylsilane –helps the filler and polymer for

reinforcement to occur

TYPES-ACCORDING TO SIZE OF FILLER PARTICLES

CONVENTIONAL 1-50 µm MICROFILLED 0.04 µm

HYBRID CLINCAL APPLICATION: •LARGER FILLER

PARTICLES-EXTRA BOND STRENGTH. •CAREFUL

REMOVAL IS NECESSARY DUE TO ACCUMULATION OF

PLAQUE

ACID ETCHING:ACID ETCHING: REMOVAL OF SURFACE

DEBRISREMOVAL OF SURFACE DEBRIS AIDS BONDING

PORES CREATED RESIN PENETRATES CREATES TAG LIKE

EXTENSIONS MECHANICAL INTERLOCKING INCREASES

SURFACE ENERGY OF ENAMEL IMPROVES WETTING.

Gwinnett and Ceen (AJO 1978) report that small

remanants of unfilled sealant did not predispose to

plaque accumulation and did begin to wear away with

time. However, this finding can not automatically be

transferred to different types of filled adhesives, some

of which have much greater wear resistance and

accumulate plaque more readily.

Brobakken and Zachrissons( AJO 1981) findings

showed that residual filled adhesive will quickly

disappear by itself after debonding; it appears

irresponsible to leave large accumulations of

adhesives.

REVERSAL OF DECALCIFICATION White spots or

areas of demineralization are carious lesions of varying

extent. The general conclusion was that individual teeth,

banded or bonded, may exhibit significantly more white spot

formation than untreated control teeth.

In a multibonded technique Gorelick et al (AJO 1982)

found that 50% of the patients experienced an increase in

white spots. The highest incidence was in the maxillary

incisors, particularly the laterals. This obvious degree

of iatrogenic damage suggests the need for preventive

programs using fluoride associated with fixed appliance

orthodontic treatment.

Zachrisson BU (AJO 1975) suggested daily

rinsing with dilute (0.05%) sodium fluoride solution

throughout the periods of treatment and retention,

plus regular use of a fluoride dentifrice, is

recommended as a routine procedure for all orthodontic patients.

Ogaard et al (AJO 1981) observed that

remineralization of surface softened enamel and

subsurface lesions are completely different

processes. The surface – softened lesions

remineralize faster and more completely than

subsurface lesions which remineralize extremely

slowly, probably because of lesion arrest by

widespread use of fluoride. Visible white spots that

develop during orthodontic therapy should therefore

not treated with concentrated fluoride agents

immediately after debonding because this procedure

will arrest the lesions and prevent complete repair

At present it seems advisable to recommend a period

of 2 to 3 months of good oral hygiene but without fluoride

supplementation associated with the debonding session.

This should reduce the clinical visibility of the white spots.

More fluoride may tend to precipitate calcium phosphate

onto the enamel surface and block the surface pores. This

limits remineralization to the superficial part of the lesion,

and the optical appearance of the white spot is not reduced.

Microabrasion Done when remineralizing capacity

of oral fluids is exhausted and white spots established.

Microabrasion: A gel prepared from 18% HCl, pumice

and glycerine is applied professionally with a modified

toothbrush tip for 3-5 mins; followed by rinsing. This

is effective for removing white spots and brownyellow

enamel discolorations. In case of more extensive

mineral loss, grinding with diamond burs or composite

restorations may be required

Enamel microabrasion is a conservative method for

removing enamel to improve discolorations limited to the outer

enamel layer. Sundfeld, et al.36 (2007) noted in an in vitro study

that the enamel microabrasion technique results in a loss of

enamel of around 25 to 200 μm, depending on the number of

applications and acids concentration. The use of various acids to

remove enamel stains was described early, in 191626. Since then,

many variations of this principle have been described. The

enamel microabrasion technique has been suggested for aesthetic

improvements, employing a mixture of 18% hydrochloric acid

and pumice14 or 6.6% and 10%35 hydrochloric acid with silica

carbide particles, or even 37% phosphoric acid gel32associated

with extra fine grain pumice in proportions of equal volume

In Figure 1 was described the usuall microabrasion

technique. A teenage girl had idiopathic white

enamel demineralization of her maxillary central

incisors (Figure 1A). The enamel microabrasion

procedures were performed after enamel

macroabrasion of the affected enamel surfaces,

using a fine-tapered diamond bur (3195 FF, Kg

Sorensen Indústria e Comércio Ltda, Barueri, SP,

Brazil) under water and air cooling (Figure 1B).

Rubber dam isolation was applied and the dental

enamel surface was treated with an application of

the microabrasive product (Opalustre, Ultradent

Products Inc, South Jordan, UT, USA), three times

on each of the three teeth at 60-second intervals

(Figure 1C, ,DD and andE).E). Teeth were polished

with Herjos F fluoridated prophylaxis paste

(Vigodent Coltene SA Indústria e Comércio; Rio de

Janeiro, RJ, Brasil). A 2% neutral-Ph sodium

fluoride gel was applied for 4 minutes. The

immediate enamel aspects were satisfactory (Figure

1F and andGG

Microabrasion Technique used to remove

superficial enamel opacities, brown-yellow

enamel discoloration, when re mineralizing

capacity is exhausted • Abrasive gel = 18%

HCL, fine pumice and glycerin Procedure: •

Isolate gingiva with rubber dam • Gel is applied

using electric tooth brush for 3-5 minutes •

Rinse for a minute • Procedure can be repeated

2-3 times/month

Enamel microabrasion is a conservative method for removing

enamel to improve discolorations limited to the outer enamel

layer.

Artun and Thylstrup(1986) after debonding, arrest

of further demineralization, and a gradual

regression of the lesion at the clinical level takes

place primarily because of surface abrasion with

some redeposition of minerals

Amount of Enamel Lost in Debonding

the reported amount of enamel loss is between 4.1 and 30 microns, which is approximately 0.05 mm3 in volume. In a clinical perspective, the enamel loss encountered with routine bonding and debonding procedures, exclusive of deep enamel fractures or gouges resulting from an injudicious use of hand instrument or burs, is not significant in terms of total thickness of enamel.

The surfaces usually bonded have a thickness of 1500 to 2000 microns. The claim that removal of the outermost layer of enamel, which is particularly caries resistant and fluoride rich, may also be harmful is not in accordance with recent views on tooth surface dynamics and with clinical experience over many years.

ENAMEL CRACKS Clinical Implication • Pre-treatment

examination of cracks and its documentation • Inform

patient if pronounced cracks are visible • Observe

cracks after debonding • Detect any horizontal cracks-

bonding/debonding technique needs improvement •

Gentle manipulation of debonding instruments

Removal of decalcification Daily rinsing with

dilute (0.05%) sodium fluoride during treatment

and retention period • Fluoride dentifrices •

Fluoride varnish in decalcified areas • Oral

hygiene measure

Caries has been demonstrated not to develop in sites even if the entire enamel layer is removed. Similarly, no histologic or clinical evidence of effects was experienced after significant of canines that had been ground to resemble lateral incisors when approximately one half of the enamel thickness was removed as long as the surfaces were left smooth and sufficient water cooling was

Operator Safety during Debonding

Recent research showed that aerosol particulates produced during enamel cleanup might be inhaled, irrespective of handpiece speed or the presence or abcence of water coolant. This aerosol may contain calcium, phosphorus, silica,aluminum, iron and lanthanum. Blood, hepatitis B surface antigen (HBsAg), and hepatitis B virus–DNA were also detected in excess fluid samples of the two hepatitis B carriers.

Although the particles are most likely to be deposited in the conducting airways and terminal bronchi, some might be deposited in the terminal alveoli of the lungs and cleared only after weeks or months.

So Barrier equipment should be used to prevent aerosol contamination.

Patients reported lower levels of pain and

discomfort when metallic brackets were

removed with lift off debonding instrument . The

use of a straight cutter plier caused the highest

pain and discomfort scores during debonding.

What is the best method for debondingmetallic brackets from the patient’s perspective?

Debonding methods used. a Lift-off debonding instrument (LODI). b Straight cutter (SC). c How plier (HP). d Bracket removal plier (BRP)

What is the best method for debonding metallic brackets from the patient’s perspective?

There is no doubt that fixed orthodontic treatment causes irreversible damage to dental enamel.

Arkansas stones, green stones ,diamond burs, steel burs, and lasers should not be used for adhesive removal. Tungsten carbide burs are faster and more effective in adhesive removal than Sof-Lex discs, ultrasonic tools, hand instruments, rubbers, or composite burs.

Effect of Orthodontic Debonding and Adhesive Removal on the Enamel –Current Knowledge and Future Perspectives – a Systematic Review

Janiszewska-Olszowska J. et al.: Effect of debonding and adhesive removal © Med Sci Monit, 2014; 20: 1991-2001

Finishing stone for composites

are made of white Arkansas

stone designed for polishing

composite and

porcelain. Polishing lab stone are

very useful for removing excess

of composite and polishing teeth.

tungsten steel burs

Arkansas stones

They remove a substantial layer of enamel and roughen its surface, and thus should be followed by multi-step Sof-Lex discs and pumice slurry, which is the most reliable method of polishing. Further efforts should be made to find tools and methods allowing complete removal of adhesive remnants to minimize enamel loss and to achieve a smooth surface after the completion of treatment with a fixed orthodontic appliance

white stone dental