How to integrate intraoral scanner data with CAD/CAM and 3D printing systems?

Ⅰ. Basic forms of data from intraoral scanners

Intraoral scanners provide a digital dental model that is usually saved as a 3D file. Some common formats are:
STL (Standard Tessellation Language)
The global format that is utilised the most
Using a triangular mesh to show the surfaces of teeth and the soft and hard tissues in the mouth
Works with most CAD/CAM and 3D printing applications
PLY (Polygon File Format / Polygon Library)
Support textures in colour and more detailed surface information
Sometimes used in orthodontic simulations or aesthetic restoration to show off the colour of the gums and the texture of the teeth
OBJ (Wavefront Object)
Help with colour and material information
Some CAD or rendering systems use it to show off visual effects.
Summary: STL is the most widespread and robust data format if you want to build restorations or 3D print models.

Ⅱ. How to connect data from an intraoral scanner to CAD/CAM

The digital dental workflow is the main focus of the data integration of intraoral scanners with CAD/CAM systems. In general, the process goes like this:

1. Getting data and doing some basic processing
Using an intraoral scanner to get 3D data on teeth and soft tissues in the mouth
Use the scanner's built-in software to clean up the data, fill in gaps, and smooth out the surface after scanning.
You can make preliminary lines on the bite connection to use as a guide while designing in CAD.

2. Exporting data
Export 3D data that has been processed as STL, PLY, or OBJ files
Check the file to see if it is complete and if there are any holes or strange triangles.
The size and resolution of the file will determine how well CAD/CAM machining works later on.

3. Design in CAD
You can import STL files into CAD programs like Exocad, 3Shape Dental System, and CEREC CAD.
Make a restoration depending on the treatment plan:
Single crown or multi crown bridge
Body embedded, veneer
Putting in the upper structure
Temporary or functional dental structures
In CAD design, you can do the following:
Change the margin line
Change in occlusion
Design for looks (morphology and shade)

4. CAM machining

After you finish the CAD design, bring the model or restoration file into CAM program.
CAM software produces files for milling pathways or slicing for 3D printing.
Find out what materials and processing methods to use:
Aluminium zirconia, all ceramic, metal porcelain PMMA, resin, and so on.
Pick the printing accuracy, layer thickness, and cutting tools.

Ⅲ. How to connect data from an intraoral scanner to a 3D printing system

Digital data is also the most important part of 3D printing.

1. Importing and dicing data
Load STL files into the 3D printing program (Slicer)
Set the precision of the printing (typically 25 to 100 microns)
Choose the kind of printing material:
Photosensitive resin for dental crowns, bridges, and guide plates
Temporary denture resin
Clear resin (dental guide or orthodontic device)

2. Design support
Software makes support structures on its own or by hand.
Make sure the printing process is stable to avoid failure or deformation.

3. Printing and finishing
Output to printer for making things
After the printing is done:
Clean leftover resin
Curing using UV
Polishing and Grinding

If it is a restoration, it can be used right away in the clinic or given to technicians for more work.

Ⅳ. Things to keep in mind while docking

1. Compatibility of data
Make sure that the intraoral scanner can read STL, PLY, and OBJ files in any format.
Make sure that CAD/CAM and 3D printing software can read this format natively.
To keep the manufacturer's closed-loop system from making it impossible to import data into other devices

2. Correctness of data
STL files should be accurate enough for repairs that need to be done at the micrometre level.
Loss or noise while scanning may make the edges of the restoration not fit right.
A good balance between speed and accuracy can be found with high-precision scanning and a good file compression ratio.

3. The software ecosystem
How well CAD software and scanners work together
Is there automated recognition of edges and bite marks, as well as the capacity to implant Scanbodies?
Does the slicing software for 3D printing work with the materials you use in your clinic?

4. A record of the biting relationship
When docking CAD, bite data is quite crucial.
Make sure that the scanner records how the upper and lower jaws are related to each other.
Make sure the printed restoration doesn't bite in the wrong way and need to be adjusted again.

5. Keeping and protecting data
There should be a way to back up data.
Don't let losing digital files get in the way of treating patients.
Think about using cloud storage or storing data on a local server.

Ⅴ. Common Problems and Solutions