A mixer (10) for preparing a dental material comprises a mixing barrel (17) and a mixing rotor (16), a mixer inlet (13, 14), and an outlet (15). The mixing rotor is rotatable about a rotation axis (A), and comprises four mixing paddle levels (21, 22, 23, 24) each comprising at least one mixing paddle. The mixing paddle levels are axially disposed over a portion of the mixing rotor with the paddle levels being axially spaced at a generally uniform paddle spacing. The mixing paddles further have a thickness in the dimension parallel to the rotation axis, and the ratio between the paddle spacing and the paddle thickness is at least 2:1, thereby maximizing the mixing efficiency, and minimizing energy consumption.