Influence of the tool-material couple on the dental CAD CAM prosthetic roughness

摘要

This study aims at investigating the tool-material couple in CAD/CAM dental machining. The tool-material couple is studied through the observation of milled surface roughness and tool geometrical properties. The influence of two tool-material couple parameters is also studied: the feedrate and the milling mode (flank, top). Three diamond burs and three dental biomaterials (ceramic, polymer, hybrid) were tested. The surface roughness was observed for nine tool-material couples in flank and top milling. Ra, Rt, Rz, Sa, Sq, Sz roughness criteria were measured. It has been concluded that in flank milling the measured surface roughness is in direct proportion to the diamond tool grain size. In top milling, the roughness is mainly due to the diamond grain size, and the radial depth is not a predominant parameter. The surface roughness was influenced by material hardness in flank milling mode. Moreover, the surface roughness was not affected by the feedrate.