A dental instrument includes a tubular member defined by side wall, a first 5 end with a first opening, a second end with a second opening and a female locking element mounted on adjacent area of the second opening; a plunger member comprising a shaft having a proximal end and a distal end in which an elongated pin attached at the distal end which is slidably inserted into interior of the tubular member via the first opening by 10 directing the elongated pin towards the second opening while the proximal end is exposed at the first end of the tubular member; a tubular conduit for delivering filling materials is removably engaged to the female locking element through an extended male locking element; wherein fitting of the elongated pin into the tubular conduit by pushing the proximal end of 15 the plunger member ejects pre-loaded filling materials to a targeted site.