A precision electric welding device is used for welding dental crowns and bridges in the mouth, the dental elements to be welded being made up of dentally suitable metals, especially of titanium and titanium alloys. The device comprises, in combination, an electronic welding base unit supplied with direct current voltage source and provided with a storage device containing a plurality of welding sequences, each welding sequence defining the energy requirements for successive pulses in a particular welding operation. The base unit generates a series of controlled voltage potentials for each operation, and an interdental precision electric welding gun is responsive to said series of controlled voltage potentials for performing the welding operations. Features of the invention include provision, on the welding gun, of a threaded rotatable rod extending between electrically conductive arms of the gun and having an operator-rotatable disk for adjustment of the bias of a carriage spring, coaxially mounted on one of the arms, against a part received between electrodes located at tips of the arms of the gun.