J Adv Prosthodont.  2023 Apr;15(2):55-62. 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

• Ciocca L
• Maltauro M
• Pierantozzi E
• Breschi L
• Montanari A
• Anderlucci L
• Meneghello R

• KMID: 2541802
• DOI: http://doi.org/10.4047/jap.2023.15.2.55

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, CoCr 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 ∆-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 ∆-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 ∆-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 ∆-mean error values of all digital protocols for manufacturing RPD frameworks optimally fit within the clinical tolerance limit of trueness and precision.

Keyword

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