A self-heating electric plugger/syringe needle (10/70) with the conductive element (50) on the external surface of the needle (10/70) is described. The needle (10/70), which can be divided into shank (30) and tip (20) portions, is hollow and is made of an electrically resistive material. A conductive element (50) located on the external surface of the needle runs along the length of its shank (30) and the length of its tip (20). An insulating material (60) located between the conductive element (50) and the external surface of the needle runs along the length of the shank (30). The conductive element (50) contacts the tip (20) of the needle, causing the needle to self-heat when electric current is supplied. A method for filling a root canal using the self-heating electric plugger/syringe needle (10/70) is also described.