Accuracy of removable partial denture framework fabricated by casting with a 3D printed pattern and selective laser sintering

Abstract

Purpose: The present study aimed to compare the accuracy of removable partial denture (RPD) frameworks fabricated by 3D-printed pattern casting and those fabricated by selective laser sintering (SLS).

Methods: A partially edentulous mandibular model was used for the simulation model. Scanning of the model was performed using a dental scanner. The framework was designed by using CAD software. The 3D-printed resin pattern was formed using a 3D printer and casting was performed (AM-Cast framework), and a direct metal laser sintering machine was used for the framework of SLS (SLS framework). 3D scanning of fabricated two types of framework were performed, and these data were overlapped with design data. Fabrication accuracy was verified using the Mann-Whitney U test to compare the discrepancy between the AM-Cast and SLS frameworks.

Results: The range of differences for the AM-Cast and SLS framework were -0.185±0.138 to 0.352±0.143mm and -0.166±0.009 to 0.123±0.009mm, respectively. Statistically significant differences were observed at the rests, proximal plates, connectors, and clasp arms. Regarding the rests, both lateral and medial displacement in the two types framework was observed in relation to the design data. Large lateral discrepancies of the connectors were observed at the joining area on the tooth-supported side of the lingual bar for the AM-Cast framework. Localized discrepancies were observed at the center of the lingual bar for the SLS framework.

Conclusion: The accuracies of RPD frameworks fabricated by AM-Cast and SLS differ depending on the specific structural component of the RPD.

Keywords: 3D-printed pattern casting; CAD/CAM; Metal framework; Removable partial denture; Selective laser sintering.