Novel computer-assisted removal method for dental crown preparation body undercut

Abstract

The invention provides a novel computer-assisted removal method for a dental crown preparation body undercut. The novel computer-assisted removal method comprises the following steps of 1) calculatingan undercut area: calculating the undercut area in an in-place direction according to the specified in-place direction; 2) converting the undercut area: taking a return value of the undercut area asan index of a triangular surface, and converting the triangular surface into grid vertexes; 3) classifying the vertexes of the undercut area: classifying the grid vertexes of the undercut area, wherein the grid vertexes in the same classification have the same motion vector when the undercut area is removed; and (4) removing the undercut area: calculating the motion vector required for removing the undercut area of the grid vertexes in each classification according to a projection algorithm, and then moving the grid vertexes. According to the novel computer-aided removal method for the dentalcrown preparation body undercut provided by the invention, automatic removal of the undercut area can be realized without human interference, and a new undercut area does not appear, so that the design of a later-period restoration body is facilitated; the in-place direction is not limited; and the method is suitable for various dental crown preparation body models.

Description

technical field [0001] The invention relates to a method for removing an undercut of a crown preparation, in particular to a computer-aided method for removing the undercut of a novel crown preparation. Background technique [0002] In clinical practice, dental crown preparations are usually obtained by manual grinding in the patient's mouth by physicians. Due to the limited operating space and field of view of the oral cavity, it is inevitable that the prepared dental crown preparations will have undercut areas. The undercut area will make the restorative crown difficult to fit, so it is necessary to remove the undercut area on the crown preparation before designing the restoration. [0003] At present, the dental CAD systems in the world also have their own undercut removal methods, but the specific methods are not clear. At present, the undercut area can be removed by calculating the positioning direction to obtain the undercut area, and then manually remove the undercut...

AI Technical Summary

Problems solved by technology

However, there are the following problems for manually removing undercuts: 1) manual removal of undercut areas is easy to generate new undercut areas; 2) if the undercut area is small, it is difficult to accurately select; 3) for larger undercut areas There are different undercut depths in the area, and different removal displacements are required, which is difficult to implement manually

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