Margin Line Detection

Margin Line

Automatically Detect Margin / Prep Lines

This feature detects Margin / Prep Lines for Crown & Bridge and Hybrid Abutment Cases automatically. There are other restoration types that can utilize the Margin / Prep Line curves, but it is dependent on how your Milling Strategy is configured and the requirements of the part you are processing. These curves are required for the CAM to determine the correct insertion direction for the restoration. 

If these curves are not specified during the nesting / setup phase, you may end up with a lot of undercut areas in your internal preps, which will cause fit issues when you try to seat your case on the die / model.

All undercuts should be blocked out in the design phase. If you need undercuts in the internal prep area of a restoration, consider using Special Tooling such as a T-Tool or a 5 Axis Undercut operation to mill these difficult-to-reach areas.

MillBox can also use 3rd Party CAD Files to help with the designation of these curves. This saves time when importing cases and ensures that the CAM uses the exact margin / prep line placement that was specified during the design phase. The necessary file(s) must be in the same directory as your .STL file and the names of both files should exactly match.

MillBox supports the following Dental CAD:

• 3Shape - MillBox can read the .PTS File output from 3Shape CAD
• Exocad - MillBox can read the .CONSTRUCTIONINFO File output from Exocad
• Dental Wings - MillBox can read the .POL File output from Dental Wings

The CAD Software must be setup properly in order to output these files and in the proper format. Please consult with your CAD Support / Dealer to ensure these options are enabled when desired.

Manually Designate Prep / Margin Line

This button allows the user to manually specify the path of the margin line. This can be useful when a .STL file lacks additional CAD data (such as margin line data) or when automatic detection fails to detect the margin during import.

You can use individual clicks to draw the margin line along the part's (A, B) surface when this function is selected. Notice that the curve will automatically follow the prep-line as you move the mouse along the margin. Close the loop to finish specifying the margin line (C to A - the original point). The user will be prompted to enter the marginal thickness and you will see the rendered margin lines once you input this value. It's crucial to remember that the accuracy depends on how accurately you draw the line.

Adjusting Margins

After the curve has been enclosed, you can make additional adjustments to any potential troublesome spots:

Stump Margin

MillBox can now recognize and mill features that must be respected when insertion directions are designed (ie. Models / Abutment Bridges) or any parts with these requirements: