An electrosurgical system includes an electrosurgical instrument having an electrode with a polymeric dielectric coating; and an electrosurgical generator, which includes a power converter configured to generate RF energy; a sensor coupled to the power converter and configured to sense a parameter of the RF energy; and a controller coupled to the sensor and the power converter. The controller is configured to control the power converter to output an RF waveform to achieve conductor breakthrough through the polymeric dielectric coating. The controller is further configured to determine whether the conductor breakthrough occurred based on the parameter; and execute a treatment algorithm based on a determination of the conductor breakthrough.