Comparison of fracture resistance between cast, CAD/CAM milling, and direct metal laser sintering metal post systems

Abstract Purpose The purpose of this study was to compare the fracture resistance of Co-Cr post-cores fabricated with 3 different techniques: traditional casting (TC), computer-aided design and manufacturing (CAD/CAM) milling (CCM) and direct metal laser sintering (DMLS). Methods Forty intact human mandibular premolar were endodontically treated. The roots were then randomly divided into four groups according to the post systems: the control group was only filled with gutta percha. Co-Cr metal posts were fabricated with TC, CCM and DMLS in the other three groups. The posts were luted with a resin cement and subjected to compression test at a crosshead speed of 1mm/min. The statistical analysis of the data was performed using one-way analysis of variance (ANOVA) and multiple comparison post hoc Tukey tests ( α =.05). The samples were examined under a stereomicroscope with ×20 magnification for the evaluation of the fracture types. Results The mean fracture loads were 432.69N for control, 608.89N for TC, 689.40N for DMLS and 959.26N for CCM. One-way ANOVA revealed significant difference between the groups ( p Conclusion While Co-Cr posts fabricated by TC and DMLS systems performed similarly in terms of fracture resistance, posts fabricated by CCM techniques showed higher fracture resistance values. Significance Co-Cr metal posts fabricated by CCM and DMLS could be an alternative to TC processing in daily clinical application.