Comparison of the mechanical properties and microstructures of fractured surface for Co-Cr alloy fabricated by conventional cast, 3-D printing laser-sintered and CAD/CAM milled techniques.
10.4047/jkap.2014.52.2.67
- Author:
Yun Jung CHOI
1
;
Jai Young KOAK
;
Seong Joo HEO
;
Seong Kyun KIM
;
Jin Soo AHN
;
Dong Soo PARK
Author Information
1. Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea. young21c@snu.ac.kr
- Publication Type:Original Article
- Keywords:
Co-Cr alloys;
CAD/CAM dental;
Dental laser sintering;
Mechanical property;
Microstructure
- MeSH:
Alloys*;
Dental Alloys;
Elastic Modulus;
Hardness;
Hardness Tests;
Tensile Strength
- From:The Journal of Korean Academy of Prosthodontics
2014;52(2):67-73
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: The purpose of present study is to compare mechanical properties and microstructural characteristics of fractured surface for cast, 3-D printing laser sintered and CAD/CAM milled cobalt-chromium (Co-Cr) alloy specimens and to investigate whether laser sintered technique is adequate for dental applications. MATERIALS AND METHODS: Thirty six flat disc shape Co-Cr alloy specimens were fabricated for surface hardness test and divided into three groups according to the manufacturing methods; 12 specimens for casting (n=12), 12 specimens for laser sintered technology (n=12) and 12 specimens for milled technology (n=12). Twelve dumbbell shape specimens for each group were also fabricated for a tensile test. Statistical comparisons of the mechanical properties for the alloys were performed by Kruskal-Wallis test followed by Mann-Whitney and Bonferroni test. The microstructural characteristics of fractured surfaces were examined using SEM. RESULTS: There were significant differences in the mean Vickers hardness values between all groups and the cast specimen showed the highest (455.88 Hv) while the CAD/CAM milled specimen showed the lowest (243.40 Hv). Significant differences were found among the three groups for ultimate tensile strength, 0.2% yield stress, elongation, and elastic modulus. The highest ultimate tensile strength value (1442.94 MPa) was shown in the milled group and the highest 0.2% yield strength (1136.15 MPa) was shown in the laser sintered group. CONCLUSION: Different manufacturing methods influence the mechanical properties and microstructure of the fractured surfaces in Co-Cr alloys. The cast Co-Cr alloy specimens showed the highest Vickers hardness, and the CAD/CAM milled specimens revealed the highest tensile strength value. All alloys represent adequate mechanical properties satisfying the ISO standards of dental alloy.
