Removable Partial Denture

Printing Strategy for RPD Frameworks with Castable Materials

Application: Removable Partial Denture
Subtype: Castable
Resin: QuraCAST
Layer Thickness: 70 μm
Software: Alpha 3D

 

1. Print Analysis

A. Critical Areas – Do Not Add Supports

  • The most important part of this print is the fitting area of the removable partial denture (RPD) against the part or soft tissue. Therefore, the RPD must be positioned so that the fitting area is facing away from the build platform.

B. Intended Support Area

  • If the fitting areas is facing up on the model, the opposite surface should be facing the build platform and will therefore be the support surface. This means more work is necessary to make it look better, but this is easier to do than manually adjusting the fitting.

2. Orientation

  1. Put the model in a horizontal position and make sure the fitting area of the abutment is facing upwards.It can be difficult to make it flat because there is a lot of the fitting area on the bottom. It does not need to be perfect. Your goal is to avoid putting supports in the fitting area.
  2. Raise the model off the platform.
    • You can automatically raise the model when you add the supports. Open the Supports panel, and set the height parameters.
    • Support Height: 1.5 – 2.0 mm

Note

The model and print area shown in Alpha 3D is actually inverted on the printer. It is easier to see and work with your model in this perspective, but the object is printed from the bottom up during the print process.

3. Supports

When adding supports to the model, we recommend the following procedure:

  1. Open the Supports panel, apply the settings as shown below (make sure to select Structure on the support Type dropdown list) and click the Auto Support button to add supports.
  2. Click the Manual Support button and remove any supports that are too close together.
  3. Add supports to any areas that have too few supports.
  4. Add more manual supports (with the Base Support settings) to the lowest points of the print to make sure that area is securely attached to the build platform.

Note

Make sure that there are no supports in the teeth fitting area. Use the Structure support type to stabilize the denture base.

Tip

Use the View Slider function to identify the lowest points of the print.

Support Area

Support Results

4. Base

We strongly recommend adding a base to your model because it allows the print to securely attach to the build platform. A base also makes the print easier to remove during processing.

  • If you use select General on the Type dropdown list, Alpha 3D automatically adds a small base to every support. These small bases are sufficient for most prints.
  • You can also key in a value for the Base Thickness setting to add a base around the entire print. This makes it easier to remove the print from the build platform.

Warning

A thicker base does not improve print performance. A Base Thickness of 0.400 mm or thicker can make a print less likely to succeed.

5. Printing

When the model that you want to print is in place, click the Printing Setup button to open the Printing Setup window.
Make sure the settings are as follows:

  • Your printer is selected on the Printer Model dropdown list.
  • Select QuraCAST on the Material dropdown list.
  • Select your Layer Thickness on the slider. We recommend a layer thickness of 70 micrometres.

Click the Print button to open the Print window and save your model as a print file. The top of the window shows your Printing Setup settings.

  • Key in a Job Name.
  • Click the Save button to save the name and settings.

Alpha 3D slices the model into layers and creates the print file. When the process is complete, it shows the IBF file in a window. You can now send this IBF file to your printer and start the printing process.

6. Finishing

When the printing process is complete, you must clean, dry, and remove the print supports.

  • Cleaning Alcohol: Ethyl alcohol (95%)
  • Ultrasonic Cleaner or Soak Time: 2 minutes

Note

It is not necessary to cure this resin in a UV oven after printing.

7. Casting

Use the casting burnout schedule shown in the adjacent graph for casting RPD framework.

Note

It is best practice to start the casting process as soon as possible to avoid the risk of deformation and to make sure the finished product is accurate.