Margin line detection

Margin line detection

The first step in the construction is the preparation margin detection. The wizard will prompt you to click on the margin line for a specific tooth [1].

As you move the mouse over the scan data, a bubble will pop up to show you a sectional 2D view of the area below the mouse pointer. This helps you to find the correct position for clicking. For crowns and related restorations, a single click will typically suffice – the automatic margin line detection will start after the first click. For inlays, four points must be selected for the detection to start.

 

Adjusting the light source to help you see the margin

You can rotate the object so that you look at it from the insertion axis, and then click button [4] to adjust the virtual light source so that it comes from this view point. If you look at the margin from the side afterwards, the shadows will help you see the margin.

 

 

Dealing with misdetected margin lines

In some cases, especially when working with non-optimal preparations, the margin line may not be detected correctly. You can help the algorithms by clicking on one or more additional points on the margin line (the 'Add point' mode, [2]. E.g. on the graphic on the right, the user has set an additional point (the purple dot) after the initial misdetection. After setting one or more points, click „Start“ [5] to relaunch the detection, which will now take advantage of your additional points.

Typically, adding a single point will be enough; in difficult cases 2-4 points may be required. Setting large amounts of points is unnecessary.

If you have erroneously clicked on a point which is not actually on the margin, switch to the „Remove point“ mode [3] and click on points to remove. Switch back using button [2] to add points again.

 

Clearing and starting over

If you have clicked on the wrong tooth, or outside of the margin, use the „Clear“ button [7] to start over again.

 

Editing the margin line

You can edit or manually draw the margin line by clicking on the „Correct/Draw“ tab, [8] in the margin detection dialog. The detected margin line changes to green color, and now features little dots, which grow as the mouse approaches them. These are the control points that help you edit the margin.

Different modes for editing the margin line are now available:

  • Move mode [1]: Here, you can drag and drop individual control points
  • Add new points by clicking on the green line
  • Remove points by clicking them with both mouse buttons (first hold the left mouse button on a point, and while holding it, click the right mouse button – the point will disappear
  • „Up/Down“ mode [2]: Drag and drop the mouse near the margin. Control points will move up or down, as if the mouse pointer was magnetic
  • „Draw“ mode [3]: Draw a portion – or the entire margin – freely. If a margin has been previously set, start drawing close to the existing margin, and add points by clicking on the object. When done, click „Accept drawing changes“ [4] to merge the newly drawn section with the existing margin line.

You can move the entire margin using the „Move margin up or down“ feature. Set the offset [5] to a nonzero value (positive to move up, negative to move down), and click „Move“ [6] one or more times to move the margin step by step.

No matter how you're editing the margin line – you can always go back one or more steps by using the „Undo/Redo“ feature. When done with the margin line editing, click „Next“ to continue to the next step.

Use <PageUp> and <PageDown> keys to rotate, to inspect the margin line from all sides.