Korean J Dent Mater.  2023 Sep;50(3):145-156. 10.14815/kjdm.2023.50.3.145.

Evaluation of the machinability and machining accuracy of dental CAD/CAM wax blocks using merlon fracture test model

• Jeong CS

• KMID: 2546958
• DOI: http://doi.org/10.14815/kjdm.2023.50.3.145

Abstract

This study evaluated the machinability and machining accuracy of dental CAD/CAM wax blocks using the merlon fracture test model specified in ISO 18675 (2022). Three types of CAD/CAM wax blocks (WAX DISK α, CASTING WAX, and MAZIC Wax) were used in this study. The merlon fracture test specimens were prepared using the CAD reference data with three different thicknesses (0.2 mm, 0.3 mm, and 0.4 mm). Ninety samples were fabricated by using a milling machine. The machinability score of the fabricated sample was counted by visual inspection. The machining accuracy was estimated by overlapping the CAD reference data and the CAD specimen data and calculating the RMS value from the overlapped data. The values of the result were evaluated by one-way ANOVA (α=0.05), and post-hoc analysis was performed using the Tukey HSD test. As a result of machinability and machining accuracy, dental CAD/CAM wax blocks showed the best machinability at a thickness of 0.4 mm regardless of type. Additionally, in the machining accuracy of the 0.4 mm experimental group, the HCW group (28.74±2.11 µm) and the VMW group (32.23±3.45 µm) were superior to the YWD group (36.94±4.31 µm) (P<0.05). Therefore, these results are expected to provide objective indicators for prior knowledge and efficient processing plans for accurate dental prostheses.

Keyword

CAD/CAM; Wax block; Machinability; Machining accuracy