Bonding in Orthodontics (2)

8/13/2019 Bonding in Orthodontics (2)

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ONDING

INORTHODONTICS

PRESENTED BY- Dr. Jasmine PannuSUPERVISED BY- Dr. Aval Luthra


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The aim of this presentation is todevelop theoretical , practical andclinical skills.

Main emphasis is on clinical aspects Topic is divided into 4 parts-

1) Bracket bonding2) Debonding

3) Bonded retainers4)Other application of bonding


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Bracket bonding Advantages when compared with

con vent ional band ing Esthetically superior Faster and simpler Less discomfort to the patient Arch length not increased by band

material

More precise bracket placement Improved Oral hygiene Partially erupted or fractured teeth can be

bonded


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Proximal enamel reduction ispossible during treatment

Attachments may be bonded toartificial tooth surface Interproximal areas are accesible for

composite buidups Proximal caries can be detected and

treated No band spaces are present to close

at end of treatment Brackets may be recycled, further

reducing cost. Lingual brackets can be used when

the patient rejects visible appliance


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Disadvantages

A bonded bracket has weakerattachment than a cementedband

Better access for cleaning does

not guarantee better oralhygiene and improved gingivalcondition Especially if excessadhesive extends beyondbracket base

Bonding is more complicatedwhen lingual auxiliaries arerequired

Debonding is more time

consuming than banding

Poor oral hygiene


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B ONDING PROCEDURE

CLEANING-remove pellicle and plaque

Polishing brush Rubber cup

Bristle brush cleansmore effectively


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MOISTURE CONTROLA fter the r inse , m ainta inin g d ry f ie ld is essent ia l

Lip expander Saliva ejecto rs

Tongu e guard w i th b i t e b locks


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Sal ivary duc t ob s t ruc to rsCot ton o r g auzero l l s

Ant is ia lagogues

Both tablet and injectable form (banthine ,probanthine, atropine sulfate etc)When indicated banthine tablet 50 mg per100lb/45 kg body wt.In sugar free drink , 15 mins before bonding


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Enamel etching The acid etch (37% phosphoric acid) is placed

on each tooth surface for ~15 seconds , thensuctioned with a high speed (HS) suction and

rinsed abundantly


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Air dry thetoothsurfaces

until theyappearf ros tywh i t e .


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Should the etch cover the entirefacial enamel or only a smallportion outside the bracket pad? etch an area only slightly larger than the

pad, however etching the entire facial

enamel with solution is harmless-at leastwhen a fluoride mouthrinse is used regularly.


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VISCOSITY -GEL S ORSOLUTIONS

Which i s bes t ???? No app arent d ifferen ce exis ts in

deg ree of su rface i r regu lar i t ies af tere tch ing B oth are eq u al ly effect iv e

How ever gels pro vide better co nt ro lfor r es t r ic t in g th e e tched area


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IS SANDBLASTING AS

EFFECTIVE AS ACID ETCHING?

Sand blas t ing fo l low ed b y ac idet ch ing p roduc es h ighe r bonds t reng ths


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IS PROLONGED ETCHING NECESSARY

WHEN TEETH ARE PRETREATED WITHFLUORIDE?

No, when in doubt check frostywhite appearance.If present , surface retention isadequate for bonding .


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Sealing A thin layer of sealant is painted

over the entire etched enamelsurface.

Is best applied with a small foampellet or brush with singlegingivoincisal stroke

Coating should be thin and even excess sealant may induce bracketdrift and unnatural enameltopography when polymerised


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BONDINGPROCEDURE CONSISITS OF Transfer- grip the bracket with a pair of

cotton pliers or a reverse action tweezer

Using Ladmore composite instrumentcoat the bracket base evenly withadhesive.

Posi t ion ing - Position the bracketas precisely as possible


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THE B RA CK ET PLA CEMENT GAUGE ISUSED DIFFERENTLY IN DIFFERENT A REA SOF THE MOUTH :

In the canine, premolarand molar regions, thegauge is placed parallel

with the occlusal plane

In the incisor regions,the gauge is placed at90

to the labial

surface.


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Excellen t bracke t ing relies on proper visualization ofthe crown, its convexity, and its long axis. Use a mouth mirror to view the crowns from the

inc isa l /occ lusa l view to establish good angulationand to ascertain correct mesio-distal positioning ofthe bracket.


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FITTING The placement scaler is turned,

and with one-point contact with thebracket, it is pushed firmly towardthe tooth surface

The tight fit will result in Good bond strength, Little material to remove on

debonding, and Reduced slide when excessmaterial extrudes peripherally .


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REMOVA L OF EXCESS Before the adhesive hasset,

excess must be removed by- An explorer Scaler

After the adhesive hasset,

It must be removed by Oval (no. 2) / Tapered (no. 1172) TC

bur

If no t , i t w i l l en co ur age p laq u eacc um ulation , and g in givali r r i ta t ion


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Several a lternat ives exis t to c hem ical ly auto po lym erizingpaste-paste sy stem s

1. No-m ix adh es ive s- These materials (e.g., Rely a-

Bond,System 1+)one adhesive component is applied to the bracke tbase while another is applied to the dr ied e tchedtoo th .

As soon as it is precisely positioned, thebracket is pressed firmly into place and

curing occurs, usually within 30 to 60 seco nd s In vitro tests have shown that liquid activators of theno-mix systems are definitely toxic allergic reactions have been reported in patients ,


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2. Visib le-l igh t p o lym erized adh esiv es-

These materials (e.g., Transbond) may becured by transmitting light through toothstructure and ceramic bracketsLight-cured composites are useful in situations

in which a qu ick se t is required, such as whenplacing an attachment on a palatally impactedmaxillary canine after surgical uncovering, withthe r i sk for b leeding .

But they are also advantageous when extral ong wo rk ing t ime is desirableFluoride-releasing, visible light-curing adhesivesare also available


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GIC Bases on reaction between polyacrylic acid and leachable

aluminosilicate glass Used primarily as lu t ing agen ts and direct resto rative m aterial ,

with unique properties for bonding chemical ly to enamel and dentin,as well as to stainless steel, being able to release fluoride ions forcaries protection.

More recently, the glass ionomer cements have been modified toproduce dual cure or hybrid cements (e.g., Fuji Ortho LC).

The resin component of these cements is strongly hydrophilic, and

excess water around the bracket during placement may lead toreduc t ion in s t reng th

Used for cementing bands because they arestronger than zinc phosphate and polycarboxylate cements,with less demin eral izat ion at the end of treatment.


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B o n d in g t o c ro w n s an d

res tora t ionBonding of orthodontic attachments to non enamelsurfaces may now be possible

The Microetcher, 50 micrometre aluminum oxide particles arecommonly used as sandblasting media

advantageous for bonding to different artificial toothsurfaces.

Rebonding loose brackets Increasing micromechanical retention for bonded

retainers , Bonding to deciduous teeth.

.


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The Microetcher 11 is an FDA-approved intraoral sandblasterthat is most useful for preparing microretentive surfaces in metalsand other dental materials, whenever needed. The appliance consists of a

container for the aluminum oxide powder, a pushbutton for fingertip control, and a movable nozzle where the abrasive particles are delivered


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Bo nd ing to po rce lain1. Isolate the working field adequatelybond the actual crown separately from the other teeth.`

2 Deglaze an area slightly larger than the bracket base bysandblasting with 50 um aluminum oxide for 3 seconds.

3 Etch the porcelain with 9.6% HF acid gel for 2 m inutes .

4. Carefully remov e the gel with cotton roll, then rinse usinghigh-volume suction.

5. Immediately dry with air, and bond bracket with highlyfilled bisGMA resin. The use of a silane is optional.


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The po rcelain su rface is resto red in a tw o-stepp rocedure .

Smoothen ing is achieved with slow-speed polishingrubberwheels, whereas

Enamel-l ike g los s can be created by application ofdiamond polishing paste in rubber cups or in specialdesigned points incorporating such paste.

Etchant create microporosities on the porcelain

surface that achieve mechanical interlock withcomposite resin


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The essent ia lsfor po rce la inbond ing :

If using Hydrofluoric Acidco ns ider the us e of g in giva l barr ierpro tec t ion .


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B ond ing to am algam

1) Modification of the metal surface (sandblasting,diamond bur roughening)

(2) The use of intermediate resins that improve bondstrengths (e.g., All-Bond 2, Enhance, Metal Primer), and

(3) New adhesive resins that bond chemically tononprecious as well as precious metals (e.g., 4-METAresins, 10-MDP bis-GMA resins).


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1. Sm al l am algam f i l l ing w i thsu r roun d ing sou nd enam el

1. Sandblast the amalgam alloyfor 3 seconds

2. Condition surrounding enamelwith 37% phosphoricacid for 15 to 30 seconds.

3. Apply sealant and bond withConcise,or similar, composite resin. Makesure bonded attachment is not inocclusion with antagonists .

SANDBLAST


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2. L arg e am algam resto rat ion , o ram algam on ly1 . Sandblast the amalgam filling for 3 seconds.

2. Apply a uniform coat of Reliance MetalPrimer and wait for 30 seconds (or useanother comparable primer according tomanufacturer's instruction).

3. Apply sealant and bond with Concise, orsimilar, composite resin.

Make sure the bonded attachment is notin occlusion with antagonists


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B o n d i n g t o c o m p o s iteres torat ives

The bond strength obtained with the addition of newcomposite to mature composite is substantially lessthan the cohesive strength of the material

However, brackets bonded to a fresh, roughenedsurface of old composite restorations appear to beclinically successful in most instances.

It is probably advantageous to use an intermediateprimer as well.


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L ing u al at tach m en ts A drawback when bonding brackets on the labial, as comparedwith banding, ---is that conventional attachments for control

during tooth movement (e.g., cleats, buttons, sheaths,eyelets) are not included.

In selected instances such aids may be bonded to the lingual surfaces tosupplement the appliance

Cleats may be needed in addition to brackets when the maxillary firstmolars have been distalized with headgear and the premolars follow themolar

cleats But tons Sheaths eyelets

Ind i rec tbo nd ing


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Ind i rec t bo nd ing Clinical chairtime is decreased Brackets can be more accurately positioned in the laboratoryInd irect Bon din g w ith Si lico ne Transfer Trays

1. Take an impression and pour up a stone (not plaster)model.

The model must be dry. It may be marked for long axis and incisal or occlusal

height on each tooth.2. Select brackets for each tooth.3. Apply a small portion of water-soluble adhesive on eachbase or tooth.4. Position the brackets on the model. Check allmeasurements and alignments.Reposition if needed.

5. For silicone tray fabrication, mix material according to thmanufacturer's instructions.Press the putty onto the cemented brackets.Form the tray, allowing sufficientthickness for strength.

f h l h h d l d h


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6 . After the silicone putty has set, immerse the model and tray in hot water torelease the brackets from the stone.

Remove any remaining adhesive under running water.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 thebonding bases.10. Seat the tray on the prepared arch and hold with firm and steady pressurefor about 3 minutes.

11. Remove the tray after 10 minutes. The tray may be cut longitudinally ortransversely to reduce the risk of bracket debonding when it is peeled off.12. Complete the bonding by careful removal of excess adhesive flash. Useoval (no. 7006 and no. 2) or tapered (no. 1172 or no. 1171) TC bur to clean thearea properly around each bracket.


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Ind i rec t bo nd ing w i th the do ub le- sealant tech n iqu e

Ad hes ive pas tes , rather than a t empora ryadhes ive , are used to attach the brackets to thepatient's stone model

Catalyst and universal adhesive pastes are

dispensed side by side on a mixing Pad Enough adhesive for one attachment is mixed

and applied to the back of the bonding base. The bracket is placed on the model The excess adhesive is removed from the

periphery of the base. This step is repeated until all brackets are bonded

to the stone model.


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After at least 10 minutes (enough time for the bondingmaterial to set) a placement tray is vacuum-formed for eacharch

Models with trays attached are placed in water untilthoroughly saturated.

Then trays are separated and trimmed so the gingival edgeof each tray is within 2 mm of the brackets.

The midline is marked with indelible ink The lingual sides of the bonding bases are painted with

catalyst sealant resin (part B). The dry-etched teeth are painted with the universal sealant

resin (part A).

The tray is then inserted into the patient's mouth, seated,and held in place for at least 3 minutes.

It is removed by peeling from the lingual toward the buccal


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Debond ing AIM---

To rem ovethe a t tachm ent and a l lthe adhesiv e res in f romthe too th

Restore the surface asc lose ly as p oss ib le to i t spre treatment con di t ion.Without induc ing

ia trog enic damage


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B rac k et rem o v al

Cut techn iqueDebonding pliers

Squeeze techniq ue By squeezing the bracket

wings with weingart pliers Gentle technique but

brackets are easilydestroyed and cannot berecycled


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The bond breaks in the adhesive bracketinterface , and

The pattern of the mesh-backing is visibleon the adhesive remaining on the teeth.


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Techn ique in remo ving Ceram icbrackets

Ceramic brackets using mechanical retention cause fewer problems indebonding than to those using chemical retention

Preferred mechanical debonding is to lift the brackets off withperipheral force application, much the same as for steel brackets

Most recent ceramic brackets have a mechanical lock base and a

vertical slot, which will split the bracket by squeezing. Seperation is at BRACKET-ADHESIVE interface , with little risk of

enamel fracture Low speed grinding of ceramic brackets with no water coolant may

cause permanent damage or necrosis of pulp ; water cooling of the grinding sites is necessary Thermal debonding and Use of lasers have potential to be less traumatic and less risky for

enamel damage


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2 Prefered m etho dis tous eaTCbu rat


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2 Prefered m etho d is to us e a TC bu r atabo ut 30,000 revolu t ion s p er m inu te

Light paintingmovements of the burshould be used

When al l adhesive has been rem ov ed, too thsurface may be po l i shed wi th pu m ice o r acom m ercia lly p ro phy lax is pas te in a rou t ine

manner

Ch t i t i f l l


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Charater is t ics o f n o rm al en am el The most evident clinical characteristics of young

teeth that have just erupted into the oral cavity arethe per ikymata * that run around the tooth over itsentire surface

IN ADULT TEETH clinical picture reflects wear and exposure to varying

mechanical forcs (eg. Toothbrushing habits, abrasive food- stuffs )

SEM app earanc e (scanninelectronic microscopy)


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Inf lu enc e on enam el b y d i fferen tdebon d ing in s t rum en t s

By proposing an enamel surface index (ESI) with 5 scores (0 to 4)for tooth appearance and using replica SEM and stepby-steppolishing, Zachrisson and Artun were able to compare differentinstruments commonly used in debonding procedures and ranktheir degrees of surface marring on young permanent teeth

1) Diamond instruments wereunacceptable (score 4); even finediamond burs produced coarsescratches and gave a deeplymarred appearance

2) Medium sandpaper disks and agreen rubber wheel producedsimilar scratches (score 3


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3)Fine sandpaper disks produced several marked andsome even deeper scratches and a surface appearancelargely resembling that of adult teeth (score 2)4) Plain cut and spiral fluted TC burs operated at about25,000 rpm were the only instruments that provided thesatisfactory surface appearance (score 1)

5) None of the instruments tested left thevirgin tooth surface with its perikymata intact (score 0).


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En am el tearo u ts Ceramic brackets using chemical retention

appear to cause enamel damage more often thanthose using mechanical retention. This damage occurs probably because the

location of the bond breakage is at the enamel-

adhesive ratherthan at the adhesive-bracketinterface The clinical implication is

(1) to use brackets that have mechanical retention

and debonding instruments and techniques thatprimarily leave all or the majority of compositeon the tooth and(2) to avoid scraping away adhesive remnants with

hand instruments.

E l k


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En am el c rac k s Fiberopt ic t ransi l lum inat ion is needed for a proper

impression of the crack

The occurrence of cracks in debonded, debanded, andorthodontically untreated teeth was discussed in a study byZachrisson, Skogan,

Vertical cracks are common (in fact, more than 50% of allteeth studied had such cracks),

Few

ho r izon tal and ob l ique cracksare observed normally

The most notable cracks(i.e., those invisible under normal officeillumination) are on the m axi llary cent ra l inc iso rs andcanines .


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B o n d ed retainers Advantages-1. Completely invisible from the front2. Reduced caries risk under loose bands3. Reduced need for long-term patient cooperation

4. Prolonged semipermanent, and even permanent,retention when conventional retainers do not providethe same degree of stability

Sub d iv is ion s us ed a re-1.Mandibular canine to canine retainers

2.Direct contact splinting3.Flexible wire retainers


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Tech nica l proc edure ofbo nd ed l ing ual3-3 re tainer

While the orthodontic appliances remain inplace, take a snap impression of the patient'steeth and pour a working model of hard stone

Using the working model as a guide, bend aplain round stainless steel or gold-coated wire

of 0.030- to 0.032-inch diameter with a fine,straight three-jaw or similar plier so that itprecisely contacts the lingual surface of allmandibular incisors

Sandblast the ends

Clean the lingual surfaces of both canineswith a TC bur


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Check the position of the wire in the mouth. Whenoptimal, fix with three or four steel ligatures around thebracket wings of the incisors

Isolation of working field is necessary

With retainer wire in place, etch the lingual surfaces ofthe canines with the Ultraetch 35% phosphoric acid gelfor 30 to 60 seconds

Rinse and dry completely. Use a high-speed vacuum

evacuator.

Sealant is not needed on lingual surfaces


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Trim along the gingival margin andcontour the bulk with an oval TC bur

(no. 7408) This s tep i s m and atory Instruct the patient in proper oral

hygiene and use of dental flossbeneath the retainer wire and alongthe mesial contact areas of both

canines


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Flex ib le s p iral w ire retain er Advantages1.They may allow safe retention of treatment results when

proper retention is difficult, or even impossible, with traditional removableappliances

2.They allow s l igh t movement of all bonded teeth and segmentsof teeth. Apparently this is the main reason for the excellent long-term results

3.They are invisible.

4. They are neat and clean .

5. They can be placed out of occlusion in most instances. Ifnot, there remains the possibility of hiding the wire undera slight groove in the enamel.

6. They can be used alone or in combination with removable retainers

T h i l d


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Technical procedure Toward the end of orthodontic treatment, take a snap

impression and pour a working model in stone.

Adapt the 0.0215-inch Penta-One steel* orgo ldcoated wire closely and passively to the crucialareas of the lingual surface of the teeth to be bonded.

Cut the wire to the required length. Check the retainer wire in the mouth for good fit in an

entirely passive state and adjust if necessary Clean the surfaces to be bonded with a TC bur and

etch with Ultraetch 35% phosphoric acid gel for 30 to60 seconds

Initial tacking is done Add bulk of adhesive Use oval TC burs (no. 7006 and 7408) to obtain correct

amount and contour of adhesive Instruct the patient in proper oral hygiene and use of

dental floss over the contact points

I d i i


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Indicat ions 1 Prevent ion o f space reopening Median diastemas(0.0215 inch 5 stranded wire

over 4 units) Spaced anterior teeth

Adult periodontal conditions with the potential forpostorthodontic tooth migration Accidental loss of maxillary incisors requiring the

closure and retention of large anterior spaces Mandibular incisor extractions2. Holding of in div id ua l teeth Severely rotated maxillary incisors

Palatally impacted canines

Di tb d d l b i l t i


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Direc t bo n d ed lab ial retainers Typical pro blem s-

1. Inability to prevent some space reopeningin closed extraction sites in adults

2. A tendency for some lingual relapse ofpreviously palatally impacted canines

3. Space reopening when molars andpremolars had been moved mesially in caseswith excess space


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Oth l i ti f


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Oth er ap p l ica tion s o fb o n d in g in o r th o d o n t ic s

Space maintainers recommended design usingrou nd 0 .032 inch SS wire

Using 6 s t rand ed 0 .032 inch sp iral wire with utility

wire design

B d d i g l t th l t


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B o nd ed s ing le too th rep lacem en t The fo l low ing pro per t ies w ere aim ed at :

1. Possibility for physiologic movement of the bridgeunits within the periodontal tissues

2. Avoidance of direct occlusal contact on metal

3. Uncomplicated repair

4. Access to the pulp cavity and root canal in caseswhere endodontic treatment might be indicated

Con st ru ct ion and app earanc eofathree w ire


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Con st ru ct ion and app earanc e of a three-w irebo nd ed, s ingle-too th rep lacem ent

Acrylic tooth fitted on a plasterworking model (PM) andtemporarily attached with stickywax.

Two braided 0.016- X 0.022-inchwires are contoured along thegingival margin of the supportingincisors; one round (0.020) spiralwire provides additional support.

The wires are bonded to theartificial crown with cold-cureacrylic


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Acrylic tooth (AT) bondedwith restorative composite

Final result .Right centralincisor madeslightly shorterthan the intactleft incisor toavoid excessiveload in eccentricmandibularmovements

Alternat ive des igns fo rs in gle-too th replacementwi th a four-wire des ignwhere two braided wires runthrough the pontic

T fi i


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Trau m a f ixat ion Temp orary f ixat ion o f several loos e m axi l lary

inc iso rs af ter in jury. Spiral w ire bond ed to f ive u n i t s . This p roc edure is s im ple, neat , and c lean.

Com po s i tebu i ldu ps po rcelain


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Com po s i te bu i ld u ps po rcelainlam inate veneers

The add i tion o f co m po s i te res in o r po rcelainlam ina tes to n on car ious tee th d ur in g o r af tero r thod on t ic t reatment m ay b e ind icated o ns ing le or m ul t ip le teeth to so lve too thsh apeand/or s ize prob lem s. Eg peg s hapedlatera ls , co m po s i te bu idu ps , prem olarauto t ransplanta t ion

Peg sh aped la tera ls

l f l i i


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Auto t ransp lan ta t ion of premolar in anteriorregion followed by composite buildups


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Co n c lu s io n The simplicity of bonding can be misleading.

Success in bonding requires- understanding ofand adherence to accepted orthodontic and preventive

dentistry principles.

In most routine cases brackets are bonded on all teeth exceptmaxillary first molars.

Banding maxillary first molars provides a stronger attachment andavailability of lingual sheaths (for transpalatal bars, elastics,headgear, etc.)

The mandibular second molar is better suited for bonding than forbanding because gingival emergence of the buccal surfaceprecedes emergence of the distal surface.


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Documents

Bonding in Orthodontics (2)