Abstract: An actuator for advancing a rod which enables release of the rod from an actuating mechanism by rotating the rod to allow the rod to be retreated. The actuator may also provide a mechanism for disabling the driving mechanism as the rod is fully advanced to prevent damage by excessive forces being applied to the rod. The actuating mechanism can be fully enclosed in a stock of a dispenser gun or applicator, facilitating cleaning of the dispenser gun. The disclosed dispenser gun is particularly suitable for dentistry applications.

Abstract: A plunger for a dispenser for cartridges containing materials to be dispensed, for example viscous materials, is disclosed, the plunger having three plunger portions which define empty spaces therebetween so that cartridges, for example two-component concentric cartridges, of a plurality of dimensions and configurations can operatively mate with the plunger. A dispenser having a plunger as described can be used with a multitude of different cartridge types, including concentric two component cartridges or cylindrical single component cartridges, of varying overall dimensions and configurations. Also disclosed is a plunger for assisting the alignment of a cartridge in the dispenser. Corresponding dispensers and methods of loading cartridges are further disclosed.