A revolving multi-cartridge syringe device includes a needle and two or three revolving holders, each for receiving a cartridge containing medical fluid to be injected. The holders can be pre-loaded with the cartridges, with a first cartridge placed in a loaded position ready to dispense. After fluid in the first cartridge is injected into a patient, a second holder and cartridge are revolved into the loaded position, without breakdown of the syringe. The process can be repeated with a third cartridge. The engagement of each cartridge with the needle, retraction from the needle, and rotation of the revolving holder are all implemented by sliding a sliding actuator in either a first direction or a second, opposite, direction, depending on which action is desired. Thus, injection and reloading of the cartridges can be easily actuated by the user through manipulation of a single slidable actuator, without requiring withdrawing the needle from the mouth area to reload.