Image Number 5 for United States Patent #6168432.
A hollow jointless needle formed from a single piece of conductive metal for injecting thermoplastic material into a dental cavity includes a flange for securing the needle to an injection device. The flange extends transversely relative to the longitudinal axis of the needle. A first needle portion having a first diameter extends from the flange along the longitudinal axis. A second needle portion extending along the longitudinal axis is connected to the first needle portion by a first transition region. The second needle portion has a second diameter which is smaller than the first diameter of the first needle portion.