Evaluation of trueness and precision of removable partial denture metal frameworks manufactured with digital technology and different materials

Leonardo Ciocca; Mattia Maltauro; Elena Pierantozzi; Lorenzo Breschi; Angela Montanari; Laura Anderlucci; Roberto Meneghello

doi:10.4047/jap.2023.15.2.55

Evaluation of trueness and precision of removable partial denture metal frameworks manufactured with digital technology and different materials

J Adv Prosthodont. 2023 Apr;15(2):55-62. doi: 10.4047/jap.2023.15.2.55. Epub 2023 Apr 25.

Authors

Leonardo Ciocca¹, Mattia Maltauro², Elena Pierantozzi¹, Lorenzo Breschi¹, Angela Montanari³, Laura Anderlucci³, Roberto Meneghello²

Affiliations

¹ Oral and Maxillo-Facial Prosthodontics, Section of Prosthodontics, Department of Biomedical and Neuromotor Science, Alma Mater Studiorum University of Bologna, Bologna, Italy.
² Department of Management and Engineering, University of Padova, Vicenza, Italy.
³ Department of Statistical Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy.

Abstract

Purpose: The aim of this study is to evaluate the accuracy of removable partial denture (RPD) frameworks produced using different digital protocols.

Materials and methods: 80 frameworks for RPDs were produced using CAD-CAM technology and divided into four groups of twenty (n = 20): Group 1, Titanium frameworks manufactured by digital metal laser sintering (DMLS); Group 2, Co-Cr frameworks manufactured by DMLS; Group 3, Polyamide PA12 castable resin manufactured by multi-jet fusion (MJF); and Group 4, Metal (Co-Cr) casting by using lost-wax technique. After the digital acquisition, eight specific areas were selected in order to measure the Δ-error value at the intaglio surface of RPD. The minimum value required for point sampling density (0.4 mm) was derived from the sensitivity analysis. The obtained Δ-error mean value was used for comparisons: 1. between different manufacturing processes; 2. between different manufacturing techniques in the same area of interest (AOI); and 3. between different AOI of the same group.

Results: The Δ-error mean value of each group ranged between -0.002 (Ti) and 0.041 (Co-Cr) mm. The Pearson's Chi-squared test revealed significant differences considering all groups paired two by two, except for group 3 and 4. The multiple comparison test documented a significant difference for each AOI among group 1, 3, and 4. The multiple comparison test showed significant differences among almost all different AOIs of each group.

Conclusion: All Δ-mean error values of all digital protocols for manufacturing RPD frameworks optimally fit within the clinical tolerance limit of trueness and precision.

Keywords: Accuracy; CAD-CAM; Digital framework; Metrological measurements; Removable partial denture.