A novel digital altered cast impression technique for fabricating a removable partial denture with a distal extension

Although computer-aided design and computer-aided manufacturing has been successfully used in fabricating removable partial dentures (RPDs), making altered cast impressions is still a time-consuming and labor-intensive process for fabricating RPDs with a distal extension. An alternative digital technique has been developed to simplify this process.

The authors present a case in which they sought to improve the efficiency and simplicity in obtaining altered cast impressions by means of digital technology. Initially, a primary plaster cast was scanned as a digital cast. Based on the digital cast, a novel custom tray was designed and fabricated using a 3-dimensional printing method. With the custom tray, the novel altered cast impression was fabricated and scanned, and the final virtual altered cast was reconstructed by a stitching method.

Based on the virtual altered cast, the authors designed the virtual RPD framework. Finally, the titanium alloy framework was fabricated using a 3-dimensional printing process, and the authors fit the final RPD to the patient.

This novel digital altered cast impression technique may eliminate interoperator variability and increase precision compared with the traditional technique.

This technique showed the potential for reducing clinical appointments, chair time, and laboratory procedures.