Dental model for 3D printing: prepare a scan step by step

Intraoral scans and other organic meshes are typically not ready for 3D printing immediately. To name a few issues, they might contain excess gingival geometry, have open boundaries, lack a stable printable base, and be fully solid, which leads to excessive material usage.

For efficient additive manufacturing, your model must be cleaned, closed, aligned, hollowed, and filled with a lightweight internal structure. This guide shows the complete workflow in MeshInspector; each step links to the full article about its tool. If the scan still has orthodontic brackets, remove them first: see Removing brackets from a dental mesh scan.

Step 1. Trim Excess Geometry

Our goal is to remove unnecessary gingival regions and create a clean boundary for base generation. Trimming ensures that only the relevant portion of the scan remains.

How to do it:

1. Click Mesh Edit › Mesh Cut & Measure.
2. Select the Spline mode.
3. Select Delete Part of Surface and Smaller Part.
4. Place control points along the gingival contour.
5. Close the path.
6. Click Cut Mesh along Spline.

See Mesh Cut & Measure for the other modes.

After trimming, the model has a clean, well-defined open boundary.

Step 2. Select the Boundary

Our next objective is to define the contour from which the printable base will be generated. For this, we need to select boundary triangles that will determine where extrusion will occur.

How to do it:

• Click Select › Select Boundary Tris. See Select Boundary Tris.

The open edge of the mesh is automatically highlighted.

Step 3. Generate a Printable Base

After that, we should convert the open scan into a closed, printable model. The Extrude Base tool closes the mesh and extends it to a flat base. The red arrow in the viewport shows the Print Direction; the base is built in the opposite direction of the arrow. See Extrude Base for all settings.

How to do it:

1. Click Mesh Edit › Extrude Base.
2. Define the Print Direction. Our recommendation: look at the model from the top, click Direct to Camera, then Find Optimal Direction.
3. Confirm that the red arrow points up, away from the future base.
4. In Options, set Fix Undercuts to Selection Only, so that only the selected boundary area is changed.
5. Click Extrude Base.

The model is now closed with a stable base.

Step 4. Align the Model

Next, it would be reasonable to ensure correct orientation relative to the global coordinate system. Proper alignment is important for predictable printing and further processing.

How to do it:

1. Click Transform › Align to Plane.
2. Click the flat base surface.

MeshInspector moves the model to the global origin and turns it so that the clicked surface lies in the plane of the axis chosen in the panel (Z by default). See Align to Plane.

Step 5. Inspect the Interior

Now, we check the internal structure before hollowing. By default, the model is completely solid, which increases material consumption during printing.

How to do it:

1. Click Mesh Edit › Section.
2. Move the section plane through the model.

See Section.

In our case, the model is fully solid. This is quite typical.

Step 6. Hollow the Model with a Defined Wall Thickness

To reduce material usage while maintaining structural strength, we create a uniform wall thickness that enables internal lattice filling.

How to do it:

1. Click Mesh Edit › Offset.
2. Select the Thickening mode. A negative Value hollows the model, and its absolute value is the wall thickness. In our case, it is −2 mm.
3. Keep Resolution at Standard.
4. Click Apply.

See Offset. For a shorter recipe that only hollows a model, see Creating a hollow dental model.

The model is now hollow with a uniform 2 mm wall thickness. You can use the Section tool again to confirm the cavity.

Step 7. Heal the Mesh

Ensure the geometry is valid before lattice generation. For that, run Mesh Repair › Mesh Healer to fix issues that could prevent the lattice from being generated. See the Mesh Healer guide.

How to do it:

1. Click Mesh Repair › Mesh Healer.
2. In Local Repair, click Repair Selected.
3. Confirm there are no critical errors.

Step 8. Generate the Internal Lattice

It is time to create a lightweight internal structure for additive manufacturing. The Lattice Structures tool reduces material usage while preserving strength.

How to do it:

1. Click Mesh Edit › Lattice Structures.
2. Set Filling Mode to Inner. This mode needs a model of two nested shells, which is what the hollowing in step 6 makes.
3. Set Kind to TPMS (triply periodic minimal surface).
4. Set Surface type to Thick Gyroid.
5. Click Apply.

See Lattice Structures.

The gyroid lattice is generated inside the hollow region. You can use the Section tool to inspect the internal structure.

Optional: Add Drain Holes

If you print the hollow model on a resin printer, uncured resin stays trapped in the closed cavity. Add one or more drain holes so that the resin can drain out and the cavity can be rinsed. A model with an open base (no bottom wall) drains through the base, and then you do not need holes. Offset and Hollow/Thicken have no drain-hole option, so cut the holes with a cylinder:

1. Click Mesh Edit › Create Simple Objects. In Use Parameters mode, on the Objects tab choose Cylinder, set its parameters and click Create. See Create Simple Objects.
2. Move the cylinder so that it goes through the base wall into the cavity.
3. Select the model, then the cylinder, and click Mesh Edit › Mesh Boolean.
4. Check that the panel shows the model as Object A and the cylinder as Object B. In the Difference row, click A - B, then click Apply.

See Mesh Boolean for the details.

Result

Through this workflow, we gradually achieved the following results:

• A trimmed model.
• A closed printable base.
• Proper global alignment.
• A 2 mm wall thickness.
• A healed mesh.
• An internal gyroid lattice structure.

The model is now fully optimized for effective 3D printing. This is how you can reduce material usage while maintaining mechanical stability.