KeyPrint KeySplint Hard and Hard Clear
Keystone Industries® KeyPrint® KeySplint Hard™ and Keystone Industries® KeyPrint® KeySplint Hard Clear™ are now available to produce splints and night guards. The materials are rigid, biocompatible resins that are ideal for fast production. KeySplint Hard is tinted and KeySplint Hard Clear is clear.

This course will cover digital prep of your splints and night guards to properly prepare them for printing.
This resin is compatible with the AO Polishing Cassette.
Download the certificate here.
Select the following option depending on which resin or cassette you are using:
- Keystone KeySplint Hard or Keystone KeySplint Hard Clearwhen using the standard C2 (M2) or D1 (M3/M3 Max) cassette.
- AO-Polish Keystone KeySplint Hard or AO-Polish Keystone KeySplint Hard Clear when using the AO Polishing Cassette (M2).
- The AO Polish workflow is only compatible with vertically oriented parts.
- Carbon does not make splint design recommendations.
- Carbon encourages users to follow the guidelines of your design software. For example, 3Shape Splint Designer requires a 1.5 mm minimum wall thickness.
- Single and double-sided splints are both easily printed.
Single-sided splint

Double-sided splint

- Ensure that the perimeter of the splint does not come to a sharp 'knife' edge, as this makes support attachment difficult.
- The perimeter should at least be as wide as the tips of the supports to ensure ample space for support connection.


Review Supports in Printer UI course for more information.
There are two options for orienting splint models when using KeySplint Hard/Hard Clear:
- vertical (90 degrees from the platform)
- 40 degrees from the platform
Read the related sections below for more information about each option.
Carbon encourages experimenting with both methods to determine which best suits your lab's designs and workflow.
Printing splints in a vertical orientation maximizes the amount of splints that can printed at once.
The information in this section applies to both single- and double-sided splints.
1. Click on Orient or Shift + O in the top bar in the printer interface.
2. In the lower right corner of the bottom bar, turn on Overhang Detection or V key and set to 40 degrees. Areas that need support will appear red.

3. Orient the splints so they are about parallel to the platform.
4. Rotate the models 90 degrees with the anteriors facing the platform. The models should be standing vertically, perpendicular to the platform.

Surfaces that have overhangs will require supports. Surfaces with supports will require finishing to ensure proper seating.
Supports hold up the part during printing. They do this by connecting platform-facing surfaces to the platform.
- Click Support in the dark gray bar at the top of screen.
- Under Position, select Above Platform to lift parts off the platform.
- Click the Manual tab and make sure Patch is selected.

- Click on the anterior surface of a splint to select a patch.
- Under the Patch tab, adjust the Overhang to between 40 and 60 degrees.
- Select a value to ensure that the patch covers the six anterior teeth.
- In the Primary Support Type dropdown menu, select Fence. Fences are easier to remove and require less finishing than other support types.
- Enter a Spacing value between 2.5 and 4 mm.
- Make sure the Boundary Fence checkbox is selected.
- Margin value should be 0 mm.
Single-sided splint

Double-sided splint

Proper orientation of splints is critical:
- Maximizes yield by minimizing print defects.
- Achieves the required accuracy and surface quality.
Single-Sided Splint
- 40º tilt with anterior rotated away from platform.
- Intaglio surface facing platform.

1. Click on Orient or Shift + O in the top bar in the printer interface.
2. In the lower right corner of the bottom bar, turn on Overhang Detection or V key and set to 40 degrees. Areas that need support will appear red.

3. Orient the splint so that the intaglio surface is facing the platform.

4. Adjust the splint so that it is mostly parallel with the platform.

5. Rotate the splint so that it is at a 40 degree angle from the platform with the posterior close to the platform.

Carbon recommends using fences. They are easy to remove and do not increase the footprint of the splint, enabling more to be fit onto the build platform.
- Click Support in the dark gray bar at the top of screen.
- Under Position, select Above Platform to lift parts off the platform.
- Click Fence.

Make sure Toggle Platform (B key) is off. This will hide the platform and allow a clear view of the splint while you are adding supports.
- Click Overhang Detection or press the V key set to 30º to find areas that need support.
- Click Esc key on keyboard to end a fence and begin another.
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- Carbon® recommends making a series of small fences, rather than making a single continuous fence, to give greater flexibility to reposition points.
- Hold down the E key and click with the mouse to reposition points.
- Click Generate to create the fence geometry. This may take a few minutes.
- Click Done in the upper left corner when finished.
- Support the entire perimeter of the platform side of the model.
- Avoid supporting areas that come in direct contact with teeth as this can affect fit and function.

You have freedom to rotate the part in the Z axis to suit your needs.

- 40º tilt with anterior rotated away from platform.
- Intaglio surface facing platform.

Double-sided splints are oriented similarly to single-sided splints. But determining which side should be supported requires comparing both sides using Overhang Detection. Carbon recommends supporting the side that has the fewest overhangs and thus requires the fewest supports. This has a number of benefits:
- Part accuracy resulting from fewer unsupported overhangs on intaglio surface.
- Minimizes time creating the supports in the software.
- Reduces resin usage.
- Reduces finishing time by minimizing support nubs.
Each splint is evaluated by duplicating it, flipping the copy, turning on the Overhang Detection tool, and then seeing which part has the fewest overhangs (red area).
If there is not a clear difference, then either side may be supported.

Proper orientation of splints is critical:
- Maximizes yield by minimizing print defects.
- Achieves the required accuracy and surface quality.
Double-Sided Splint
- 40º tilt with anterior rotated away from platform.
- Mandibular or maxillary surface facing platform to minimize supports.

Perform an initial orientation of the model so that it is roughly parallel with the platform with the posterior region facing the lower portion of the screen.
1. Click Orient in the main bar in the printer software.

2. Adjust the splint so that it is mostly parallel with the platform. Either side of the splint can face the platform.

Now the splint must be duplicated and flipped.
- Click Layout in the main bar in the printer software.
- Click the splint model to select it.
- Enter 1 in Number of copies and click Duplicate.
- A duplicate of the model will appear.
- Click Orient in the main bar.
- Type 180 in the Y Axis field and press Enter.
- Click Layout again.
- Move the models apart from each other so they do not overlap.
You now have 2 copies of the splint:
- One with maxillary impression facing the platform.
- One with mandibular impression facing the platform.
Now both splint models need to be rotated so that we can compare the overhangs.
- Click Orient in the main bar.
- Make sure both models are selected.
- Rotate the splints until the anterior portions are at 40 degrees from the platform.
- The posterior of the splint should be touching the platform.

- Click Toggle Platform button in the lower toolbar or press the B key to hide the platform. This will allow you to see the overhang areas clearly.
- Click Overhang Detection or press the V key and set to 30º to find areas that need support.
- Orient the camera so that you see the models from the platform side and can clearly see the red overhang areas.
- Orbit around the models to make sure you can see all overhang areas.
- You may want to adjust the model tilt ±5º to reduce overhangs. You can adjust the models independently.
- After carefully comparing the models, delete the model that has the most overhangs. If there is no clear difference in overhang area, just pick one.

The remaining model is now ready to be supported.
Carbon recommends using fences. They are easy to remove and do not increase the footprint of the splint, enabling more to be fit onto the build platform.
- Click Support in the dark gray bar at the top of screen.
- Under Position, select Above Platform to lift parts off the platform.
- Click Fence.

Make sure Toggle Platform (B key) is off. This will hide the platform and allow a clear view of the splint while you are adding supports.
- Click Overhang Detection (V key) and set to 30º to find areas that need support.
- Click a series of points on the perimeter of the splint to define a fence.
- Click Esc key on keyboard to end a fence and begin another.
- Carbon recommends making a series of small fences, rather than making a single continuous fence, to give greater flexibility to reposition points.
- Hold down the E key and click with the mouse to reposition points.
- Click Generate to create the fence geometry. This may take a few minutes.
- Continue steps 1 - 4 until the entire perimeter is supported.
Double sided splints may require additional supports, especially for overhangs on the anterior lingual surfaces. Use Patch supports for these areas.
- Click Patch.
- Click an area of overhang.
- Under Patch, set Overhang to 30º.
- Set Primary Support Type to Fence.
- Check the Boundary Fence box.
- Click Generate All to create the supports.
- Repeat as needed for additional areas of overhang.
- Support the entire perimeter of the platform side of the model.
- Avoid supporting areas that come in direct contact with teeth as this can affect fit and function.
- Double-sided splints may require additional supports on polished/cameo surfaces.

- If the supports are attaching at a horizontal angle, they may detach during printing causing part deformation. Supports should attach to the surface of the part that is facing the platform creating vertically oriented support tips. Please reapply the supports and move the attachment points to address this issue if this problem occurs.
-
You have freedom to rotate the part in the Z axis to suit your needs.

- 40º tilt with anterior rotated away from platform.
- Intaglio surface facing platform.


Click Print Controls or Shift + P in the top menu bar.

- Slice Thickness should be Standard (100 µ).
- Reducing the slice thickness by choosing the Fine (50 µ) or Super-fine (25 µ) settings will increase print time and may reduce part quality and accuracy.
-
- Select the Project Analysis tab.
- Click Start Analysis and wait for the processing to complete.
- Note the required resin volume and print time.
- Click Add to Queue.

Reminder from the Keystone Industries® KeyPrint® KeySplint Hard™ IFU:
Using a clean foam swab dipped in IPA, wipe the entire intaglio surface of each part.

All approved curing units use the same settings for both KeySplint Hard Clear and KeySplint Hard with the following exception:
- Hard Clear - Use program Splint HC/KG
- 8 mins at 90% intensity with Nitrogen.
- Hard - Use program Splint HT
- 10 mins at 90% intensity with Nitrogen.

- A yellow tint is expected and normal after curing parts printed in the KeySplint Hard and KeySplint Hard Clear resins.
- The yellowish tint will fade away within 24-48 hours.
- If after this time period you are still experiencing issues with discoloration, please contact Carbon Support with a detailed description of the issue.

The final color of your tinted splints is dependent on the cure chamber used. Curing parts in the PCU LED chamber results in a gray tint, while the Otoflash and PCU 90 cure chamber result in a light violet tint. The Uvitron Intelliray 400W will produce a coloration that falls between the PCU LED and PCU 90.

KeySplint Hard Clear is translucent after curing. Polishing reveals a water clear appearance.

For questions about the resin properties, printing, washing or curing your parts, please contact the Keystone technical team:
- Email: [email protected]
- Phone:
- U.S. and Canada 1-800-333-3131
- EU +49 77 31 91 21 01