Assessment of mechanical properties and microstructure of Co-Cr dental alloys manufactured by casting, milling, and 3D printing
| dc.contributor.author | Schettini, Ana Cecília | |
| dc.contributor.examiningcommittee | Franca, Rodrigo (Restorative Dentistry) | |
| dc.contributor.examiningcommittee | Solomon, Charlene (Restorative Dentistry) | |
| dc.contributor.supervisor | Pesun, Igor J. | |
| dc.date.accessioned | 2024-07-11T16:47:25Z | |
| dc.date.available | 2024-07-11T16:47:25Z | |
| dc.date.issued | 2024-07-10 | |
| dc.date.submitted | 2024-05-25T18:27:02Z | en_US |
| dc.date.submitted | 2024-07-10T18:18:09Z | en_US |
| dc.degree.discipline | Restorative Dentistry (Prosthodontics) | |
| dc.degree.level | Master of Dentistry (M.Dent.) | |
| dc.description.abstract | Purpose The aim of the present study is to investigate the effect of the three different Co-Cr manufacturing processes on the mechanical properties and microstructure of Co-Cr dental alloys. Methods Dumbbell-shaped specimens (n=6) were fabricated with CAST (lost wax casting technique), CNC (computer numerical control milling), and DMLS (direct metal laser sintering) techniques. The mechanical propertied were evaluated following the (ISO) standard 6892. Tensile test was performed to evaluate 0.2% yield strength, tensile strength, elongation, and elastic modulus, 3- point-bending test was done for flexural strength, and microhardness test to analyze hardness. The microstructure was evaluated through scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), as well as X-ray diffraction analysis (XRD) for alloy phase identification. Statistical differences for the tensile test, 3-point-bending, and hardness were evaluated by oneway ANOVA followed by post hoc Tukey tests to determine the interaction among the groups. Results The DMLS groups showed the highest values for 0.2% yield strength (908.0±13.1MPa), tensile strength (1123.7±6.5MPa), flexural strength (2273.0±43.2MPa), and microhardness (438.2±44.9HV) followed by CAST (462.1±8.0MPa, 632.6±23.7MPa, 1351.2±35.7MPa, and 400.0±33.3HV respectively) and CNC (413.0±10.0MPa, 533.1±17.4MPa, 1155.6±41.7MPa, and 295.0±22.1 HV respectively). No statistical differences found for elongation between CNC (15.3±3.9%) and DMLS (10.1±0.6%), as well as for DMLS (10.1±0.6%) and CAST (2.3±0.2%) (P>.05). No statistical differences found for elastic modulus among all groups (P>.05). EDX 2 revealed a slightly different chemical composition among the groups. XRD spectra revealed facecentered cubic (fcc) as the dominant phase and a small amount of hexagonal close-packed (hcp) in all three tested groups, as well as a peak of σ phase identified exclusively in the CAST group. Conclusions The mechanical properties and microstructures of Co-Cr dental alloys is dependent on the fabrication method. Overall, DLMS specimens performed better than CAST and CNC. | |
| dc.description.note | October 2024 | |
| dc.identifier.uri | http://hdl.handle.net/1993/38321 | |
| dc.language.iso | eng | |
| dc.rights | open access | en_US |
| dc.subject | Cobalt-chromium alloy | |
| dc.subject | Printing | |
| dc.subject | Milling | |
| dc.subject | Mechanical properties | |
| dc.subject | Microstructure | |
| dc.title | Assessment of mechanical properties and microstructure of Co-Cr dental alloys manufactured by casting, milling, and 3D printing | |
| dc.type | master thesis | en_US |
| local.subject.manitoba | no | |
| oaire.awardTitle | Tylman Grant | |
| project.funder.name | American Academy of Fixed Prosthodontics |