Method for selecting margin line point, and dental cad device therefor

A margin line point picking method using a dental computer-aided design (CAD) device, the margin line point picking method comprising, by the dental CAD device:

• obtaining an abutment model, into which a prosthesis model will be inserted, and displaying the obtained abutment model on a screen;
• detecting picking of a margin line point on the abutment model due to an operation by a user on the screen on which the abutment model is displayed and generating a search area based on a position of the detected point;
• picking the picked margin line point as a final margin line point in a case in which the picked margin line point coincides with a preset margin line point within the search area;
• generating a margin line including the picked final margin line point;
• and
• in a case in which the preset margin line point and the margin line point picked by the user are different from each other and an error occurs, displaying an error occurrence area including the margin line point causing the error in a distinguished manner using identifiable visual information or providing a warning message that informs of the occurrence of the error.