INNOVATIVEAn

Indirect Bonding Approach to Lingual Fixed

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by Dr. Marco Pinto

1. Wiechmann, D. and Nesbit, L. Braces/Incognito Clinical Guide, Version 2. Lingualcar, Inc. 2007

This article will review the advantages of indirect bond-ing using a 2D lingual bracket system, as well as establishefficient and effective treatment protocols. Upon comple-tion of this article the dental professional will be able to:

1. Understand the basic advantages of indirect bondingas well as lingual fixed orthodontics

2. Apply efficient/effective indirect bonding techniques 3. Meet the aesthetic concerns of patients by provid-

ing lingual fixed orthodontics as a viable treat-ment alternative

Introduction

Consistent with the aesthetic trends in society,“invisible” orthodontics is becoming more and moredesired by both adult and adolescent patients. In con-trast to aesthetic ceramic or plastic brackets, lingualorthodontics is completely invisible. Lingual bracesdeliver both patient satisfaction and a clinically excel-lent result.1

Although orthodontic therapy traditionally addresseslong-term aesthetic concerns of the patient, aesthetic

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impairments such as sub-surface enamel lesions (whitespot lesions) are common risks of fixed orthodontictreatment.1,2 Regardless of the preventive therapy effortstaken to reduce labial enamel decalcifications, suchimpairments are a common outcome of treatment anddifficult to reverse with conservative measures. With lin-gual fixed orthodontic therapy, decalcifications have nonegative aesthetic outcome.1

In addition to providing an aesthetic alternativefor fixed orthodontic treatment, lingual braces alsooffer a unique mechano-therapeutic advantage.1 Eventhough lingual orthodontics is particularly known asadvantageous in expansion and bite opening cases, itis also effective in many other complex cases.1

Considering that a lingual archwire is approximatelyone-third the length of a labial archwire, in applying alinear stress/strain behavior model, it makes sense thata shorter wire is more compressed and can offer agreater corrective force.1

Bite opening is another great advantage of utilizinglingual braces. While bite opening is rarely successfulwith a labial continuous archwire, lingual braces canopen the bite immediately.1 The placement of the max-illary lingual brackets acts as a stop and opens the bite.The posterior open bite closes shortly after.1

Just as traditional labial orthodontics require carefulplacement of the bracket, so does lingual orthodontics.More specifically, an engaged lingual bracket is typicallycloser to the center of resistance. It is therefore essentialto consider the difference in moment force generatedfrom lingual bracket placement versus labial placement.3

There are many types of orthodontic brackets tochoose from when using fixed orthodontic therapy.However, when you consider a cost-effective bracket

that is easy to use and comfortable for the patient,many would agree that the Forestadent 2D Lingual sys-tem is a leading bracket.4 Due to its extremely flat andsmooth profile, the Forestadent 2D Lingual bracketprovides an excellent clinical result all while promotingpatient compliance.4

Although indirect bonding is a common techniqueused in lingual orthodontics, the new, innovative, indirectmold presented in this article possesses unique proper-ties that help minimize bracket failure during clinicalremoval of the stent. In contrast to a more rigid tradi-tional indirect stent, which might shear the bracket awayduring clinical removal, this new flexible mold can beinverted and peeled away without compromising thebracket bonding.5

In conclusion, lingual brackets provide an entirelyaesthetic alternative without compromising a lastingaesthetic impairment, such as labial decalcifications. Bytreating with an indirect bonding technique, the dentalprofessional can ensure a more accurate bracket place-ment. Using indirect bonding is not only easier on thepatient and the dental professional, but also facilitates amore efficient and effective treatment process.5

Lingual Brackets – Indirect

Bonding Protocol

Placing lingual brackets using indirect bonding tech-niques takes place in three stages:

1. Pre-Laboratory a. Take quality alginate impressions

2. Laboratory a. Prepare casts b. Place brackets c. Apply PVS d. Apply Thermo-Polymere. Remove and trim indirect molds

3. Clinicala. Prepare patient b. Prepare teeth c. Prepare indirect mold d. Place indirect mold and light cure e. Remove indirect mold f. Remove flash g. Place archwires, ligatures, etc.

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2. Proffit, W.R., et al. Contemporary Orthodontics, 4th Ed. St. Louis: Mosby; 2007

3. Silvia et al. Anchorage Loss- A multifactorial Response

4. Forestadent: German Precision in Orthodontics, 2D Lingual Brackets, 2010. World Wide Web. Accessed 9/29/2010 from

http://www.forestadent.com/forestadent-en/Produkte/products/2D_Lingual_Brackets.php?navanchor=1710026

5. Pinto, M.A. ”Indirect Bonding Using Forestadent™ 2D-Lingual Bracket System” American Association of Orthodontics Guest

Presentation. Washington D.C., 2010

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Stage One, Pre-Laboratory

Take quality alginate impressions and prepare arma-mentarium. Although two items (*) are relatively expen-sive, a very small amount of the material is used. This isan extremely cost-effective method.5

Armamentarium (Fig. 1): Gloves Pencil Bracket gauge Separating medium Dappen dish Brushes Instruments (bracket tweezers, explorer and scissors)Forestadent 2D Lingual brackets Bracket composite Composite gun Curing light PVS material (clear)*PVS gun PVS adhesive Thermo gun Glue sticks #15 scalpel FlowTain*

Stage Two, Laboratory

Prepare Casts: Placing lines along the long axis of the tooth will

help with accurate bracket placement. It is helpful tocontinue the lines alongthe soft tissue aspect ofthe cast. Next, using abracket gauge, mark theappropriate inciso-gingi-val distance per figure 2.After the lines are drawnon the cast, apply a thinlayer of Liquid FoilSeparator to the lingualaspect of the casts (Fig. 3).5

Apply composite and place brackets in appropriatepositions on the lingual aspect of the casts. Remove excess

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Bracket Placement: (as measured from incisal/occlusal edges)

»

Upper CI: 4.0mmUpper LI: 3.5mmUpper Ca: 4.5mmUpper premolars and molars: height of marginal ridgesLower CI: 4.0mmLower LI: 4.0mmLower Ca: 4.5mmLower premolars and molars: height of marginal ridges

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Approach to Lingual F

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composite and cure for 10 seconds (preferably using acomposite cured by heat). Notice how the cingulummight present a unique challenge (Fig. 4).5

Apply Clear PVS: Fill a mini-syringe with clear PVS material to allow

for more accurate coverage. Use the mini-syringe, andcover the entire bracket with PVS material. Once thePVS material is set, apply a layer of PVS adhesive to thePVS. This allows the Thermo-Polymer material toadhere to the PVS. Note that the PVS material must beclear to allow efficient light cure of the final bracketplacement (intra-oral) (Fig. 5). You are now ready toapply the Thermo-Polymer and fabricate the mold.5

Apply Thermo-Polymer:Cover all bracketed teeth with copious amount of

Thermo-Polymer. Be sure that the Thermo-Polymercovers the entire clinical crown of each tooth. Once theglue is placed, allow it to harden and cool for five minutes before proceeding. Next, place the casts withattached mold in a cold water bath for three to five minutes (Fig. 5).5

Remove and Trim Molds: Remove the mold by lifting it away from the cast

beginning from the corner. Trim and shape excessThermo-Polymer using scissors. Place a V-shaped notchbelow the lingual anterior incisors. This will help withan easier removal during the clinical delivery (Fig. 6).5

Stage Three, Clinical

Prepare the patient, indirect mold and teeth; lightcure, remove mold and flash.

Organize required armamentarium: Gloves Indirect molds Etch Bond Brushes Dri-Angles Composite gun Bracket composite Curing light Scissors Basic instrument kit Pumice Cheek retractors Floss

First, prepare the indirect mold by wiping the bond-ing surface with acetone. Note that there is no need tomicro-etch or sandblast the brackets.5 Once the indirectmold is ready, prepare the patient. Place Dri-Anglesadjacent to parotid duct in buccal vestibules to decreasecontamination via saliva. Next, place check retractors inthe patient’s mouth to increase the working field. Inorder to minimize saliva contamination, it is importantto prepare only one arch at a time. Place etch on one

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arch following manufacturers guidelines. Next, rinse anddry. Apply bonding agent to arch following manufac-turer’s guidelines. Air thin and cure bonding agent for 10seconds. With the indirect mold bonding surface alreadywiped with acetone, working quickly, place a smallamount of FlowTain (flowable). Do not use regularcomposite as it will lead to excess flash (Fig. 7).5

Carefully place the mold in the patient’s mouth. Donot press hard on the lingual surface while adapting themold intra-orally. The mold should fit perfectly onto theteeth. Light cure for four minutes with the mold inplace. Be sure to light cure from both positive and nega-

tive angles. After ensuring placement of the lingual V-notch, gently remove the mold from the labial aspectof the teeth by inverting the mold “inside-out” (Fig. 9).After the labial side is inverted, peel away mesially or dis-tally the lingual aspect.5 If this technique is applied,bracket failures during clinical removal of the stentshould be minimal to none.5 Light cure the bracketsagain to ensure complete bonding. With the lingualbrackets now firmly positioned, it is possible to removeany excess flash that might be present around the brack-ets. Using the Transbond LV allows for minimal to noflash (Fig. 8).5

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Author’s Bio

Dr. Marco Pinto, a native of South America, moved to the U.S. to attend college, dental school and to specialize in orthodontics and dentofacial ortho-

pedics. The focus of his practice is the application and advanced study of lingual braces. Dr. Pinto has held teaching positions at University of Kentucky

College of Dentistry and the Orthodontic Graduate Program at The Arizona School of Dentistry. He is Director of the Pre-Doctoral Orthodontic

Curriculum and the Orthodontic Rotation Program. With an outstanding commitment to community, he founded the Hispanic Dental Student Association

(Bluegrass Chapter) and is currently working with the YMCA on a mentorship program for minority students. Contact Dr. Pinto at marcopinto77@gmail.com.

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