Abstract: A medical or dental probe having a resistive, integrally heated tip including a superelastic material such as nickel-titanium alloy. The probe tip provides a nearly continuous, controllable heat, and it may have a narrow, pointed shape. The tip may be heated rapidly, and it provides rapid heating of the instrument, continuous supply of heat for the purpose desired, and concentration of maximum heat at the end of the tip. The added flexibility allows the tip to follow the curvature of a canal of a tooth without the need to pre-bend the tip which increases the working life of the tip and provides for improved packing of the material used to fill the root canal.