Application of CAD/CAM milling technology in fabrication of removable partial denture framework

Abstract

Objective To investigate the clinical application of CAD/CAM milling technology in the fabrication of removable partial denture (RPD) framework. Methods A total of 26 patients with Kennedy Ⅰ dentition defect were selected and divided into the conventional group and CAD/CAM group by random number table method, 13 in each. Individual tray and polyvinyl siloxane were used to take impressions. 13 digital casts in CAD/CAM group were obtained by plaster model scanning and the frameworks of RPD were designed by computer-aided design (CAD) . The resin frameworks were milled by computer-aided manufacture (CAM) , and the RPD metal frameworks were completed by conventional embedding and casting. The other 13 RPD frameworks in the conventional group were fabricated with the routine method. To compare the differences of the try-in and fitness between the frameworks made by the two kinds of processing technics, the Mann-Whitney test of independent samples was used. Results Nine frameworks in the conventional group were emplaced smoothly, while the other four cases faced a small amount of grinding. In the CAD/CAM group, 10 frameworks were emplaced smoothly, and three cases were emplaced with slight grinding. There was no significant difference of the try-in between the frameworks made by the two methods (U = 78.0, P = 0.50) . 12 frameworks in both groups fitted well, and one framework showed no more than 3 sites with slight gaps. There was no statistically significant difference between the fitness (U = 84.5, P = 0.76) of RPD frameworks prepared using the two methods. There was no significant difference of the try-in and fitness between the frameworks made by the two methods. Conclusion RPD framework made with CAD/CAM milling technique could meet clinical requirements. Key words: Computer-aided design; Denture partial removable; CAD/CAM milling technology; Removable partial denture framework