Required Hardware, Software, and Materials

Made by Formlabs:

• Formlabs SLA 3D printer with a compatible Resin Tank and Build Platform

• IBT Flex Resin

• PreForm Dental Software (free)

• Form Wash or Finish Kit

• Form Cure

Made by Third Parties:

• Dental design software for the design of the bonding tray or a dental design service provider

• Heat-resistant clear container (for curing)

• Optional: light-safe container for storing the appliance

Required Clinical Inputs and Data

• A physical or digital impression

• Patient treatment plan data

• A CBCT scan, which is optional depending on the specific design software requirements

To design an indirect bonding tray, dental software requires a digital impression of the patient's anatomy. This digital data can be acquired through an intraoral scan, a negative scan of a physical impression, or a scan of a plaster model using a desktop 3D scanner.

Although not mandatory, some indirect bonding tray design software can utilize CBCT data. This data is highly beneficial for both case planning and setup.

This section provides essential design parameters and best practices for creating an indirect bonding tray. While these guidelines are generally applicable across various software solutions, such as 3Shape Ortho System, BlueSkyPlan, Onyxceph, OrthoSelect, or others, users should consult their specific CAD provider's documentation. Note that the visuals in this section are from 3Shape Ortho System.

Alternatively, you have the option to outsource the appliance design and manufacturing file creation to a dental CAD service provider, such as a specialized dental laboratory or dental design center, by sending them the digital impression and your requirements.

3.1.1 Insertion Direction

For optimal bracket retention and ease of insertion, select the correct insertion direction, ideally straight from the occlusal or slightly from the frontal aspect. The insertion direction is critical as it affects how offsets and undercuts are applied.

3.1.2 Appliance Construction and Type

There are typically two ways to set up and create indirect bonding trays:

1. Bar

2. Offset

For IBT Flex Resin, Formlabs offers compatibility with both bar and offset designs.

The bar design may offer the following advantages during use:

• Flexibility around brackets since the appliance is still thin in critical areas

• Thicker bottom surface providing some useful rigidity to the appliance

• Ability to print directly on the build platform, removing the need for support structures

3.1.2.1 Container Design and Coverage

In our testing, we found half- or three-quarter container coverage the best way to design indirect bonding tray appliances, especially using the bar design.

Please respect a minimum wall thickness of 2 mm for the tray.

3.2.1 Containers ( 3Shape )

3.2.2 Finalization ( 3Shape )

3.2.2.1 Optional: Using Plane Cuts

The bar-type design, if supported by your software, is an excellent choice because it allows for printing flat on the build plate, eliminating the need for supports.

For instance, within the Bar Design workflow of 3Shape Ortho System, this setup can be achieved during the final step, Modify model.

The suggested modifications, illustrated in the two screenshots below, utilize the plane cut tool. The primary objective of the first cut is to flatten the tray's occlusal surface (1). A secondary cut is then applied in this example to introduce a chamfer (2), which is intended to facilitate the removal of the parts from the build plate post-printing.

3.2.3 Design Settings and Offsets for the Tray Shell

The recommended values for the tray shell in 3Shape Ortho System are provided below. These fundamental values apply across all software packages. Keep in mind, however, that the specific options and terminology may differ depending on the software you are using.

With the case design finalized according to specifications, the manufacturing process can begin. Most dental design software will produce a manufacturing file in the STL format. Find this file and import it into PreForm.

Import or open the design file(s) by dragging them into PreForm Dental, or use the File menu to locate them on your computer or network.

1. In the Job Setup menu on the right side, click the printer box to select your printing material.

2. Do not use a predefined Preset (1), as PreForm does not offer one for IBT Flex bonding trays.

3. Select your printer (2). Under Choose Material, select IBT Flex Resin (3) and the desired layer thickness.

4. For IBT Flex bonding trays, 0.1 mm layer thickness (4) works well. You may choose 0.05 mm for finer details.

5. Click Apply (5) to finalize your job setup.

For appliances designed with the bar-type design, the bottom surface can be adhered directly to the build platform.

Open the Orientation tool (1) and click the Select Base (2) button.

Next, click the bottom surface (3) of the part to adhere it to the build platform and confirm by clicking Done (4).

If you need to print multiple trays, add them all to your job. Ensure they are placed on the build plate without overlapping. The Layout All tool under PreForm's Layout menu can simplify this arrangement process.

Once the layout is complete, the job is ready to send to the printer. Send the job to the printer by clicking Print Now. If your printer is not ready to print, the button will change to Upload to Queue, and will start printing once you have prepared your printer.

Shake the IBT Flex Resin cartridge and then insert the cartridge, a build platform, and a compatible resin tank into the Formlabs 3D printer.

• Begin printing by selecting the print job from the printer’s touchscreen.

• Follow any prompts or dialogs shown on the printer screen.

• The printer will automatically complete the print.

Always use gloves when handling uncured resin and parts.

Remove printed parts from the build platform by wedging the Part Removal tool or a spatula under the part and rotating the tool.

Place printed parts in a Form Wash or Form Wash L filled with isopropyl alcohol (IPA, ≥99%) and wash them for the time established in the Manufacturing Guide.

Make sure the parts are fully submerged in IPA when washing.

If your part geometry traps residual resin, it may be beneficial to lightly swish a paintbrush back and forth along the bracket pockets midway through the wash cycle.

Exceeding wash duration may affect dimensional accuracy and performance of printed parts over time.

Watch this video to learn how to properly wash your IBT Flex Resin bonding tray.

Remove parts from IPA and leave to air dry at room temperature for at least 30 minutes in a well-ventilated area.

Compressed air can be used to help dry parts and allow for rapid inspection of unwashed resin. Still allow time for sufficient bench drying if using compressed air.

Inspect printed parts to ensure that parts are clean and dry. No residual alcohol, excess liquid resin, or residue particles must remain on the surface before proceeding to subsequent steps.

If any wet, uncured resin is still present after drying, use a squeeze bottle with fresh IPA to remove the uncured resin. Lightly swishing a paintbrush back and forth along the bracket pockets may also help with the removal of uncured resin. After removal, dry the parts again. The use of compressed air allows for rapid inspection.

To maintain dimensional accuracy and biocompatibility, specific post-curing instructions must be followed.

Printed parts should be cured while submerged in a transparent, water-filled container inside a Form Cure using the settings established in the Manufacturing Guide.

If indirect bonding trays are printed with rafts and supports, place printed parts in the Form Cure with the raft side down. If the trays are printed directly on the build platform without supporting structures, place the part in the Form Cure with the intaglio surface of the appliance facing up.

If supports were used, remove the supports using the clippers provided in the Formlabs Finish Kit, or scissors.

After support removal, if any support structures are left on the surface of the 3D printed indirect bonding tray, you can remove them with a set of sharp Iris scissors.

Inspect the appliance. Discard and reprint it if any damage or cracks are detected.

While working with orthodontists, we found having the right UV curing light greatly improves the adhesion of the brackets through the indirect bonding tray. A fairly affordable, high-powered light we recommend is the Ledex WL-090+ Curing Light.

Fully post-processed parts can be cleaned using neutral soap and room temperature water.

After cleaning, always inspect parts for any cracks. Discard if any damage or cracks are detected.

The indirect bonding tray may be cleaned and disinfected according to facility protocols.

Our tested method of disinfection involves soaking the finished indirect bonding tray in fresh 70% IPA for five minutes.

After disinfection, inspect the part for cracks to ensure the integrity of the indirect bonding tray.

When not in use, place printed parts in closed, opaque or amber containers.

Store in a cool, dry place out of direct sunlight. Excess light exposure over time may affect the color and performance of printed parts.

Store the cartridges at 10–25 °C (50–77 °F). Do not exceed 25 °C (77 °F) when in storage. Keep away from ignition sources.

1. Any cured resin is non-hazardous and may be disposed of as regular waste.

• Follow facility protocols for waste that may be considered biohazardous.

2. Liquid resin should be disposed of in accordance with government regulations (community, regional, national).

• Contact a licensed professional waste disposal service to dispose of liquid resin.

• Do not allow waste to enter storm or sewer drainage systems.

• Avoid release into the environment.

• Dispose of contaminated packaging as unused product.