Additively Manufactured Commercial Co-Cr Dental Alloys: Comparison of Microstructure and Mechanical Properties

Abstract

Laser-powder bed fusion (LPBF) is one of the preferred techniques for producing Co-Cr metal structures for dental prosthodontic appliances. However, there is generally insufficient information about material properties related to the production process and parameters. This study was conducted on samples produced from three different commercially available Co-Cr dental alloys produced on three different LPBF machines. Identically prepared samples were used for tensile, three-point bending, and toughness tests. Light microscopy (LM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) analyses of microstructure were performed after testing. Differences were observed in microstructures, which reflected statistically significant differences in mechanical properties (one-way analysis of variance (ANOVA) and Scheffé post hoc test (α = 0.05)). The material produced on the 3D Systems DMP Dental 100 had 24 times greater elongation ε than the material produced on the Sysma MySint 100 device and the EOS M100 machine. On the other hand, the material produced on the EOS M100 had significantly higher hardness (HV0.2) than the other two produced materials. However, the microstructure of the Sysma specimens with its morphology deviates considerably from the studied group. LPBF-prepared Co-Cr dental alloys demonstrated significant differences in their microstructures and, consequently, mechanical properties.

Laser Powder Bed Fusion of Co-Cr: A Material Comparison

“…Metallic dental devices produced using LPBF of Co-Cr alloys show adequate yield strength, tensile strength and elongation as compared to cast Co-Cr alloys in a study which was conducted by Viderščak, Dalibor. et al [1]. It was reported by Viderščak, Dalibor.…”

“…It was reported by Viderščak, Dalibor. et al [1] that the flaws typically found in cast Co-Cr alloys alloy were reduced in the samples that were processed using LPBF due to the homogeneity of the LPBF process. The mechanical properties of the Co-Cr samples processed using LPBF were found to be suitable for dental use according to the ISO 22674:2016 standard [2] and the tensile test data showed that the results achieved for a LPBF Co-Cr alloy are superior to that of a cast Co-Cr alloy Segbaya [3].…”

Low cycle fretting and fretting corrosion properties of low carbon CoCrMo and additively manufactured CoCrMoW alloys for dental and orthopedic applications

“…3 While there is data on the corrosion, microstructure, and osteointegration of additively manufactured Co Cr alloys, there is less on the fretting corrosion and wear properties. [4][5][6] This is especially true in relation to dental applications, since oral cavities feature varying situations influencing the tribocorrosion response of such alloys. 1 Additive manufacturing is growing in orthopedics in total joint arthroplasty for patient-specific implants and instrumentation, porous structures, as well as being applied in other novel applications.…”

“…PBF includes selective laser sintering (SLS), electron beam melting (EBM), and selective laser melting (SLM), with SLM being the most popular in dentistry 3 . While there is data on the corrosion, microstructure, and osteointegration of additively manufactured CoCr alloys, there is less on the fretting corrosion and wear properties 4–6 . This is especially true in relation to dental applications, since oral cavities feature varying situations influencing the tribocorrosion response of such alloys 1 …”

Characterization of Co-Cr-W Dental Alloys with Veneering Materials Manufactured via Subtractive Milling and Additive Manufacturing LDED Methods

“…However, Co-Cr alloys are expensive, and the milling from disc technique has a low material efficiency for personalized parts, such as dental prostheses. That is why in recent years, additive manufacturing (AM) techniques have been studied as an alternative to traditional milling for Co-Cr alloys [19][20][21][22].…”