An apparatus for dispensing bone cement includes a cartridge for containing the bone cement. The apparatus also includes a plunger insertable into the cartridge. An impedance sensor is coupled to the plunger and configured to produce an output signal indicative of an impedance of bone cement contained in the cartridge. The apparatus may also include a processing circuit configured to determine an impedance value of bone cement contained within the cartridge based on the sensor signal. The processing circuit may activate a visual indicator based on the impedance value to indicate that the dough time, the end-of-work time, and/or setting-time of bone cement contained in the cartridge has been reached.