Bonding Rituals by Paul Gange Jr.

Categories: Orthodontics;
Bonding Rituals

Chairside insights for digitally guided orthodontics

by Paul Gange Jr.

Editor’s note: When it comes to bonding, few people in the industry have more knowledge than Paul Gange Jr., vice president of Reliance Orthodontic Products. Gange has spent years in the field, in the lab and in operatories helping to develop some of orthodontics’ most popular and reliable products, which made him a natural to share insights into best practices for some of the newest treatment tools and options available to orthodontists: printed metal appliances and indirect bonding trays.

Printed metal appliances
“Printed metal appliances,” “sintered metal appliances,” “absolute magic” … however you prefer to refer to the newest form of appliance delivery, its technology is gaining traction in the orthodontic world.

Unlike traditional circumferential bands, however, printed appliances have more in common with buccal tubes or large acrylic appliances when it comes to the bonding process. For that reason, several top labs in the U.S. that pioneered the metal printing process have asked me to consult on appropriate bonding scenarios.

Traditional bands commonly use a luting cement that fills any gaps between the band and tooth, physically locking the band to the tooth. Printed appliances, meanwhile, depend heavily on the bond strength developed between the interior of the appliance (devoid of mesh, like a buccal tube) and the properly primed tooth surface.

The appliance is ready to deliver from the lab because the printing process naturally creates mechanical retention to the interior of the appliance. Adherence to the proper delivery steps is essential for successful bonding, but equally as important for removal.

Ideal bonding steps are as follows:
  1. After a thorough prophylaxis, etch the full buccal and lingual from gingivae to cusp tips (Figs. 1–3). Do not etch any occlusal surface that is not covered by the appliance. (A gel etch makes this process easier.)
  2. Apply a hydrophilic primer to only the buccal surface (Fig. 4)—priming the lingual makes removal significantly more difficult—and air-dry.
  3. Apply a thin bead of a dual-cure compomer around the interior circumference of the appliance (Figs. 5a and 5b), then seat it.
  4. Tack-cure flash with a curing light for one second, then remove all flash as one cohesive piece (Figs. 6–8).
  5. Cure from the occlusal, touching the appliance for 30 seconds per tooth (Fig. 9).
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Fig. 1
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Fig. 2
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Fig. 3
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Fig. 4
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A powder-liquid glass ionomer (PLGI) may be used in place of a dual-cure compomer. Because of the polyacrylic acid in the liquid of most PLGIs, there is a partial self-etching tendency so etching is not necessary; consider it optional to increase strength. Similar to priming a large acrylic appliance with plastic conditioner to establish a chemical bond between the acrylic and the adhesive, either prime printed appliances with a metal conditioner or use a band cement that autonomously bonds chemically to metal.

Removal is similar to traditional band or buccal tube removal. Using deband pliers, place the metal blade gingival to the wire tube and nylon pad on the occlusal (Fig. 10). With a gentle rocking motion, try to establish cohesive fracture; once both quadrants have fractured, remove the appliance (Fig. 11).

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Fig. 10
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If the proper steps in the bonding process have not been followed previously and removal is very difficult, segmenting the bands should be considered to avoid enamel fracture. Adhesive-removing pliers commonly used to remove bulk composite from anterior teeth at debonding can also aid in printed appliance removal by using the blade that traditionally scrapes composite to grab the buccal gingival side of the appliance aggressively.

Lastly, be advised that because these appliances are not placed subgingivally, the surface to be bonded can be very small with short crown molars, partially erupted teeth or the presence of gingival operculum. In these cases, advising the labs to add more printed area over the occlusal to better retain the appliance should be considered.

Digitally guided indirect bonding
For years, Reliance has been designated by the most popular digitally guided indirect bonding (IDB) systems—including Lightforce, Dibs, Braces on Demand and KLOwen—as a preferred manufacturer of adhesive and primer. Having sat chairside for countless bondings of these revolutionary systems, I’ve assembled below a collection of tips to ease the learning curve of the IDB process.

Etching: As with traditional direct bonding, proper etching technique is essential to a successful delivery appointment. With any printed bracket or customized system, bracket placement may seem obscure (the mesial/distal of the bracket starting almost fully on the interproximal contact) compared with traditional tooth-centered placement. There are two ways to ensure the location of the bracket is properly etched:
  • Area-specific etching. Advise clinicians to reference the digital view of the bracket location and etch that specific area accordingly. This can be tricky because the arch needs to be rotated on the media screen as the team member works from one quadrant to the next.
  • Entire surface etching. Advise clinicians to etch the entire facial tooth surface, similar to the etch process for application of decalcification-preventing sealants. The risk involved with this technique is that the “decal” process begins on any etched areas not covered by a primer. If primer (filled or unfilled) is subsequently applied to the entire etched surface, decal concerns from the exposed etched surface are null.
If both arches are to be bonded, I strongly recommend applying etchant, suctioning and rinsing one arch at a time. Repeat for the second arch and dry everything together. If placement jigs will be “tried in” before the final placement, this should be done before etching to preserve the exposed enamel rods.

Primer/adhesive interface: From a high-level perspective, outside of proper etching technique, one of the most neglected, misunderstood and vital aspects of bonding is the preservation of the chemically clean interface at the primer/adhesive contact. Specific to digitally guided systems, the teeth should be exposed to the oral environment as an etched surface, not a primed one.

Tray delivery: Many leading digitally guided systems feature a “clean base” IDB method. The primary drawback to any clean base indirect bonding is having to ensure the paste has been properly buttered into the mesh of the clean bases. With direct bonding, clinicians have unlimited access to the bracket mesh and a spatula can be used to properly smear the adhesive into the undercuts. IDB’s placement jigs and delivery trays complicate this process by blocking the access of an applicator.

Modifying a nylon spatula by cutting the blade along the long access to reduce the width is one option. A composite filling instrument can be used as well to “pad” the composite into the bracket bases. Both techniques should involve a coat of primer on the instrument to reduce stringing of the paste. Once the trays or jigs are loaded and ready for delivery (be sure to read the “Preloading” section at the end of this article), the etched surfaces should be desiccated and primer placed immediately to preserve the primer/adhesive interface.

Considering the inherent contamination complications of bonding in the oral cavity, the discussion becomes a worse of two evils: bonding to dried contamination with a hydrophilic primer versus bonding to contamination with a filled delivery material. Because of the strength and ability for hydrophilic primers to bond in contaminated fields, I believe the worse of two evils is definitely contamination at the primer/ adhesive interface.

The ideal scenario is as follows:
  1. Etch both arches and isolate diligently.
  2. Desiccate only the teeth involved in the jig (anterior sextant jig, posterior jig, quadrant jig, full-arch jig, etc.).
  3. Apply hydrophilic primer to only the involved teeth; air-dry and tack-cure.
  4. Insert jig with preloaded composite and tack-cure from the exposed gingivae to all brackets.
  5. Revisit first bracket and full cure from gingivae.
  6. Remove trays and full cure again from incisal.
Tray removal: Because of the rigidity of many placement jigs, removal can be difficult. To aid in this process, heat is your best friend. Tooth dryers are great not just for eliminating the self-induced aspect of air line contamination but also for softening placement trays. Aim the dryer close to the facial and facial/incisal edge for 30 seconds, then immediately remove the trays from the lingual. This same effect can be mimicked by having the patient hold warm water in their mouth.

Mucosal irritation relief: With the revolution of custom lingual bracketing systems, the need to provide relief for the patient’s tongue is as important as ever. The appeal of hidden ortho treatment quickly fades to the discomfort of lingual appliances.

Traditional paraffin wax has been the takehome relief for decades, but the demand was increasing for a more semipermanent solution. Two similar products are available for clinicians to place at time of bonding or as irritation arises. Reliawax (Reliance Orthodontic Products, USA) and SoftFlow (Dentos, South Korea) are flowable, light-cured, irritant-relief gels. Clinicians desiccate the area of the appliance causing irritation (Fig. 12), apply the flowable gel to the specific area (Figs. 13–15) and light-cure (Fig. 16). Both products cure to the malleability and flexibility similar to a hot-glue gun material (Fig. 17).

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Fig. 12
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Fig. 16
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Preloading: Whether considering preloading a clear aligner attachment delivery tray or a clean base IDB jig, the countless hours that can be saved chairside is hard not to mention. The key to reduced flash with IDB is the same as with clear aligners—the perfect volume applied to the bracket (Figs. 18–20). Training one clinician to be an expert at this process is an opportunity to greatly reduce flash; some practices will choose one staff member to be the “preload pro” and offer incentives such as a few hours of overtime pay Monday mornings for opening the office and loading all the trays for that week.

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Fig. 18
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We have to be acutely aware of two exterior factors in this process: ambient light and ambient air. Any light-cure paste, flowable or packable, can be sensitive to ambient light from sunlight, patient lights or even overhead office lights (especially if they use LED bulbs). Consider light filters for drop ceilings, light boxes, or limiting the overhead exposure in the lab to make it an ideal location to perform this preload process.

Once preloaded, attention needs to be given to eliminating ambient air that can dry out the resin or encounter humidity contamination in any light-cure paste. Place preloaded jigs in an airtight plastic zip-close bag (Fig. 21) and reinforce the seal by placing the bag into an airtight plastic storage container (Fig. 22) for the ideal method to stop any air exposure. Lastly, the container should be placed in a light-impervious orange box (Fig. 23) or simply wrapped in tin foil (Fig. 24) to stop any ambient light exposure during storage.

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Fig. 21
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Fig. 22
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Fig. 23
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Fig. 24

Author Bio
Dr. Glenn Krieger Paul Gange Jr. is the vice president of sales and operations at Reliance Orthodontic Products. He has become a leader in resolving difficult technical bonding issues through countless chairside hours training clinical staff. His passion for research and development has influenced many new Reliance products and aided numerous research projects. Gange, a published author, lectures domestically and internationally at numerous universities, study clubs and constituent meetings, as well as for the American Association of Orthodontists.

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