Detecting Margin Lines

Automatically Detecting Margin Lines/Prep Lines

You can use this function to automatically detect margin lines/prep lines of crowns, bridges, and hybrid abutment cases. There are other types of dental prostheses that can use the curves of margin lines/prep lines, but this depends on how the cutting strategy is set and on the requirements of the dental prosthesis to mill. CAM requires these curves to judge the correct insertion direction of the dental prosthesis.

If these curves are not specified in the placement/setup step, a large number of undercut areas will occur in internal preprocessing, which may lead to fit problems when you attempt to mount the dental prosthesis on the abutment/model.

In DGSHAPE CAM, you can use the CAD metadata to set the attributes of these curves. Doing so not only saves time when importing dental prostheses but also enables CAM to accurately use the placement of the margin lines/prep lines specified in the design step. The required file is in the same directory as the .STL file, and both file names must match.

DGSHAPE CAM supports the following dental CAD metadata.

3Shape - .PTS files output from 3Shape CAD can be loaded in DGSHAPE CAM.
Exocad - .CONSTRUCTIONINFO files output from Exocad can be loaded in DGSHAPE CAM.
Dental Wings - .POL files output from Dental Wings can be loaded in DGSHAPE CAM.

To output these files in the appropriate formats, the CAD software must be set up appropriately. To check that all these options are enabled, contact your CAD support center or your authorized DGSHAPE Corporation dealer.

Cavity Margin

Use this button to manually specify the path of the margin line. This function is useful when there is no additional CAD meta data (such as margin line data) in the .STL file and when margins cannot be detected automatically during importing.

With this function selected, each click causes a margin line to be drawn along the surface of the dental prosthesis. When you move the mouse pointer along the margin, the curve is automatically tracked to overlap the prep line. To close the loop, specify the start point of the margin line. You are then instructed to enter the thickness of the margin. When you enter this value, the rendered margin line is displayed. Note that differences in the accuracy will arise depending on how correctly the line is drawn.

Adjusting Margins

When the curves are drawn, you can further adjust any locations that may cause problems.

Stamp Margin

In DGSHAPE CAM, before performing cutting, you can recognize the characteristics (model, abutment bridge, etc.) that need to be considered when designing the insertion direction and the dental prosthesis that meets these requirements.