Evaluation of the machinability and machining accuracy of polymer-based CAD/CAM blocks using merlon fracture test model

• Published in: Dental Materials Journal Vol. 42; no. 2; pp. 273 - 281
• Main Authors: JEONG, Chang-Sub, MOON, Joon-Mo, LEE, Hee-Jeong, BAE, Ji-Myung, CHOI, Eun-Joo, KIM, Sung-Tae, PARK, Youngbum, OH, Seunghan
• Format: Journal Article
• Language: English; Japanese
• Published: Japan The Japanese Society for Dental Materials and Devices 25.03.2023; Japanese Society for Dental Materials and Devices; Japan Science and Technology Agency
• Subjects: Blanks; CAD/CAM; Ceramics; Computer-Aided Design; Dental materials; Fracture testing; Machinability; Machining; Machining accuracy; Materials Testing; Model testing; Polymer-based CAM block; Polymers; Polymethyl Methacrylate; Polymethylmethacrylate; Surface Properties; Machinability; Polymer-based CAM block; Machining accuracy; CAD/CAM
• ISSN: 0287-4547; 1881-1361
• DOI: 10.4012/dmj.2022-154

The aims of this study were to estimate the machinability and machining accuracy of polymer-based CAM blocks using the merlon fracture test model specified in ISO 18675: 2022. Three hybrid disc blanks (MazicDuro, HC Disk, and Enamic) and three polymethyl methacrylate (PMMA) disc blanks (PMMA Disk, PMMA Block, and MazicTemp Hybrid) were tested in this study. The machinability was evaluated by assigning scores according to the fracture range of merlons with areas divided by ten vertical planes. The machining accuracy was evaluated by superimposing methods via CAD reference data and CAD specimen data. Within the limits of this study, a thickness of 0.3 mm is recommended for the clinical application of polymer-based CAD/CAM blocks in dental restorations that require superior machinability and accuracy. In addition, the machinability and machining accuracy tests of polymer-based CAM blocks are expected to provide guidelines for preparing accurate dental restorations.