A powered dental tool dispenses a liquid dentifrice from a removable and replaceable cartridge to a dental site being cleaned or otherwise treated. The tool mounts the cartridge to receive a supply of the dispensable liquid, and accommodates the removal and replacement of a spent cartridge. A removable and replaceable cartridge for supplying dispensable liquid to a dental tool is initially sealed, is readily installed in the tool with a connection to a dispensing tube, and is collapsible for emptying it. A multiple-treatment dental care system has a single power handle that operates interchangeable with a fluid dispensing spray implement, with a rotary treatment implement, and with a revolving-bristle brush implement. In addition to dispensing fluid with the spray implement, the system can dispense liquid material to the dental site being treated by way of the rotary implement and by way of the revolving brush implement.