Dental Restorations Packing Based on the Contour Similar Features Matching and Collision Strategy

Dental restoration is a complex process to recover patients' teeth using artificial materials. It is important to improve the utilization of the expensive material for cost saving. The tooth side surface is projected as a two-dimensional (2D) contour in the actual processing, which forms a packing problem of irregular contours. The 2D irregular packing has received a lot of attention in research to solve this NP-hard problem. Contours of the dental restoration are more complicated than those in traditional 2D irregular packing problems. The existing packing methods cannot obtain good results for these complex contours. In order to solve the contour packing problem of restoration models using the NC machining technology, a dental restoration contour packing algorithm is proposed based on the contour similar feature matching and collision. The algorithm uses dynamic programming for the longest common subsequence to search the solution of 2D free contour packing. Comparing with the existing packing methods, our proposed method can significantly reduce the processing time and improve the filling rate.