In vitro Assessment of Fit Accuracy of Removable Partial Denture Frameworks Fabricated by Milling, Selective Laser Melting, and Conventional Methods

INTRODUCTION: In many clinical situations, removable partial denture (RPD) frameworks are used when bone and tissue support are lost. This research was done to estimate the fit accuracy of RPD frameworks created by Milling technique, selective laser melting (SLM), and the traditional means using gypsum models. MATERIALS AND METHODS: A total of 30 partially edentulous casts with Kennedy class-I level were separated into three groups of 10 samples each. The RPD structures of Group I were produced with the use of chromium-cobalt in the cooling slope (CS) casting technique; Group II with the use of chromium-cobalt in the SLM method; and Group III with the use of polyether ether ketone (PEEK) in the milling system. Gypsum models were made by filling the frames constructed with polyvinyl siloxane and weighing the rubber laminas. The data obtained was evaluated statistically. RESULTS: The biggest gap was observed between the group of SLM structures and the group of CS frameworks. The group of Milling frameworks having the better accuracy for the gypsum models. CONCLUSIONS: The structures of the RPD structures created with PEEK by means of the milling technique had the highest accuracy of fit on the gypsum models, in contrast to the Cr-Co structures fabricated with the two methods, where the exactness depended on the fabricating method.