A nozzle for an oral irrigator device, comprising: an elongated body having a channel; a guidance tip located at one end of the elongated body, wherein said guidance tip includes an orifice coupled to the channel and configured to expel a fluid as one of a jet, a spray, or any combination thereof, said orifice having a principal axis; and a dynamic nozzle actuator positioned within said guidance tip, wherein said dynamic nozzle actuator comprises an effective channel and at least one responsive material adapted for being energized in a prescribed manner and configured to implement at least one dynamic actuation of said effective channel for dynamically influencing at least one of (i) a direction of fluid expelled from the orifice, (ii) a spray angle of fluid expelled from the orifice, (iii) a cross-sectional width of fluid expelled from the orifice, and (iv) any combination thereof, characterized in that the at least one dynamic actuation of the effective channel comprises a motion imparted to the effective channel selected from the group consisting of translation and/or rotation and optionally in combination with resizing, wherein said translation is provided by translating the effective channel between a first position and a second position, wherein the first and second positions of the effective channel are different lateral positions perpendicular to the principal axis of the orifice, and said rotation is provided by rotating the effective channel between at least a first radial position and a second radial position with respect to a plane perpendicular to the principal axis of the orifice. an elongated body having a channel; a guidance tip located at one end of the elongated body, wherein said guidance tip includes an orifice coupled to the channel and configured to expel a fluid as one of a jet, a spray, or any combination thereof, said orifice having a principal axis; and a dynamic nozzle actuator positioned within said guidance tip, wherein said dynamic nozzle actuator comprises an effective channel and at least one responsive material adapted for being energized in a prescribed manner and configured to implement at least one dynamic actuation of said effective channel for dynamically influencing at least one of (i) a direction of fluid expelled from the orifice, (ii) a spray angle of fluid expelled from the orifice, (iii) a cross-sectional width of fluid expelled from the orifice, and (iv) any combination thereof, characterized in that the at least one dynamic actuation of the effective channel comprises a motion imparted to the effective channel selected from the group consisting of translation and/or rotation and optionally in combination with resizing, wherein said translation is provided by translating the effective channel between a first position and a second position, wherein the first and second positions of the effective channel are different lateral positions perpendicular to the principal axis of the orifice, and said rotation is provided by rotating the effective channel between at least a first radial position and a second radial position with respect to a plane perpendicular to the principal axis of the orifice. said translation is provided by translating the effective channel between a first position and a second position, wherein the first and second positions of the effective channel are different lateral positions perpendicular to the principal axis of the orifice, and said rotation is provided by rotating the effective channel between at least a first radial position and a second radial position with respect to a plane perpendicular to the principal axis of the orifice.