Crowns and Bridges
Printing Strategy for Crowns and bridges with Temporary Materials
Application: Crown and Bridge
Layer Thickness: 100 μm
Software: Alpha 3D
Dental Model Orientations
Dental models may be printed a number of different ways:
A. Horizontal: Accurate, requires the least print preparation time, and prints the fastest for individual prints, but takes up the most build platform space
B. Angled (10-15°): Highest possible accuracy and smoothness, but requires the most print preparation and support cutting time
C. Vertical: Fastest printing method for mass production, but slowest for individual prints
When should I print angled?
The angled orientation is best used when accuracy and smoothness are more important than the time invested to make the print. For example, when aesthetics are important, such as when prints are going to be attached to articulator interfaces and shown directly to patients, then it may be better to print at an angle.
When should I use a different orientation?
In general, the angled orientation takes the most work to set up and to print. The horizontal orientation is not as smooth and may encounter resin leakage holes, but generally meets most accuracy needs without the set up time. More models can be printed in less time with the vertical orientation. If your prints are being used in the lab setting, either other orientation may suit your needs better.
1. Print Analysis
A. Critical Areas – Do Not Add Supports
- The most important part of this print is the fitting area of the crown and bridges against the part or abutment. Therefore, the crowns must be positioned so that the fitting area is facing away from the build platform.
B. Intended Support Area
- If the fitting area is facing up on the model, the tooth surface will 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.
- 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 it is all tooth surface area at the bottom. It does not need to be perfect. Your goal is to avoid putting supports in the fitting area.
- 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
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.
When adding supports to the model, we recommend the following procedure:
- Open the Supports panel, apply the settings as shown below, and click the Auto Support button to add supports.
- Click the Manual Support button and remove any supports that are too close together.
- Add more manual supports to the lowest points of the print to make sure that area is securely attached to the build platform.
- Add supports to any areas that have too few supports.
You must select an object to add supports to that specific model. You cannot use the Auto Supports or Manual Support functions with all models at the same time.
Use the View Slider function to identify the lowest points of the print.
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.
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.
When all of the models that you want to print are 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.
- QuraCROWN is selected on the Material dropdown list.
- Select your Layer Thickness. We recommend a layer thickness of 100 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.
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
- Suggested UV Oven: Ackuretta UV Oven
- Suggested UV Oven Time for QuraCROWN: 30 seconds on the bottom side; turn the print over; 30 seconds on the top side.
- Suggested UV Oven Time for QuraCROWN LT:
- A2 color: 3 minutes and 30 seconds on the bottom side; turn the print over; 3 minutes and 30 seconds on the top side.
- A3 color: 3 minutes and 30 seconds on the bottom side; turn the print over; 3 minutes and 30 seconds on the top side.
- B1 color: 3 minutes and 30 seconds on the bottom side; turn the print over; 3 minutes and 30 seconds on the top side.
Flash curing starts automatically when you press the Start button on the Ackuretta UV Oven. We strongly recommend you use flash curing because flash curing reduces resin distortion, but you can press and hold the Start button if you want to use continuous curing instead.