One of the biggest benefits of printing your own in-office aligners is having a digital 3D dental model on hand instead of an alginate impression that needs to be poured up with stone. Using an intraoral scan to generate an stl file provides not only a quick and comfortable service to the patient but also a permanent file that can be used for the patient’s records. Printing technology has evolved to the point where 3D scanning coupled with a slicer can produce hundreds of dental models with ease. 

Using Autodesk Meshmixer Software

Meshmixer is CAD software that can be applied to numerous dental appliances. Though there is not a Meshmixer dental-specific software, it has an incredibly wide range of tools that can be used toward fabricating virtually any appliance attributed to its incredible versatility. There is a gentle learning curve that makes this process easy for both assistants and doctors to use to prepare the dental models for 3D printing. Learning how to first edit a 3D dental model sets the foundation for creating a plethora of appliances in the future.

Steps to prepare your 3D dental model

1. Import the .stl file into Meshmixer.

2. Fill holes. Follow the next few steps to fill the holes that could have occurred from your 3D scan. 

• Click on “Analysis” on the left-hand side of the screen.
• Click “Inspector.”
• Click on dots floating around the model. Do NOT click on the dot that creates a continuous boundary around the model. In this photo, click on the pink dots. Do NOT click on the red dot. Your dot color may vary.
• Click “Done.”

3. Trim away edges to create a smooth base.

• Click “Select.”

OPTION 1: Use your mouse to trace circles around jagged edges of the base by clicking, holding, and dragging. Make sure to start your circle outside of the model and circle the portion of the model you want to erase. Make sure to connect the circle until only the part you want to select is colored orange. If you select something you do not want, press “Clear Selected.” Press “Delete” on the keyboard and continue around the entire arch.

OPTION 2: Click outside of the model and extend the mouse a few mm, then click and drag around the perimeter of the model to trim it off smoothly. This eliminates the need to create numerous circles around the perimeter. Close the circle and delete it when it turns orange.

• Click on the “Analysis” then “Inspector” to make sure there are no holes in the model. If there is no other dot than the boundary, continue to the next step. Do NOT click on the boundary dot. In this photo, do NOT click on the blue dot. Your dot color may vary.

4. To extrude the model:

• Press Control + A on the keyboard to select the entire model.
• Select > Edit > Extrude.
• Drag “Offset” to the maximum mm.
• Accept.

5. Create flat base:

• Click “Edit” on the left side of the screen.
• Press “Plane Cut.”
• Use the arrow widgets to rotate the plane OR use the mouse to click and drag a line where you want to cut the base.
• Use the widgets after you draw the line to rotate and adjust the base to your liking.
• Check for holes one more time: click on the “Analysis” then “Inspector” to make sure there are no holes in the model. Do NOT click on the boundary dot.

6. Make the model solid:

• Click “Edit” then “Make Solid.”
• Increase solid accuracy and mesh density to bring back definition.
• Click “Update.”
• Click “Accept.”
• Export your file.
• Send the 3D dental model to your printer.

Next, learn how to add text to your model with a label.