Patent ID: 7748980

Claim:
An apparatus for dispensing dental compositions, the apparatus comprising: a) a body comprising a top shell portion, a bottom shell portion, and a chamber received therein; b) a replaceable cartridge having at least two lumens with at least two pistons, the cartridge operable to dispense a component of a dental compound contained within the lumens, and wherein the cartridge is further operable to be at least partially inserted into the chamber; c) an inner mechanical system disposed in the body, the inner mechanical system comprising a rack system, said rack system having at least two racks operable to be urged forward to engage a piston in each lumen of the cartridge; d) a button system in contact with the body, the button system operable to be depressed in a direction substantially forward and in line with the rack system by a user such that the button system engages the inner mechanical system when depressed, such that the rack is advanced a predetermined distance such that a metered amount of the components of the dental compound is dispensed from the at least two lumens; and e) wherein the inner mechanical system further comprises a plurality of teeth disposed on the rack system, and a drive spring and a pawl spring disposed on the body, the drive spring and the pawl spring being operable to interface with at least one of a plurality of teeth on the rack system and at least one surface of the button system such that depression of the button system by a user initiates drive spring to advance the rack system a predetermined distance proportional to the distance between a first selected tooth located on the rack and a second selected tooth located on the rack and initiates the pawl spring to disengage from a third selected tooth on the rack and engage a fourth selected tooth on the rack located at a distance substantially equal to the distance between the first tooth and the second tooth, and release of the button causes the drive spring to disengage from said first selected tooth and engage the second selected tooth on the rack.