Ultrasonic surgical systems comprising (1) ultrasonic signal generators, (2) probe assemblies each including a handpiece and a piezoelectric transducer assembly mounted and contained in the handpiece for producing, upon energization with an alternating-current electrical signal from the generator, an ultrasonic vibration at an operative surface of a probe connected to the handpiece, (3) irrigant fluid systems each including various hoses, a reservoir, a pump, a housing, and fittings that connect to the handpiece and to the housing for guiding water or other liquid from the reservoir to the handpiece and the probe, and (4) user interfaces including hand controls, switches and electrical wiring for enabling user control of the ultrasonic surgical systems. Ultrasonic surgical systems comprising (a) ultrasonic signal generators, (b) probe assemblies each including a handpiece and a piezoelectric transducer assembly mounted and contained in the handpiece for producing, upon energization with an alternating-current electrical signal from the generator, an ultrasonic vibration at an operative surface of a probe connected to the handpiece, (c) irrigant systems each including various hoses, a reservoir, a pump, a housing, and fittings that connect to the handpiece and to the housing for guiding water or other liquid from the housing to the handpiece, and (d) user interfaces including hand controls, switches and electrical wiring for enabling user control of the ultrasonic surgical systems