Access radio button inside vaadin-dialog?

I am using a vaadin-grid, inside which I have iron-form. In the iron-form there is a vaadin-radio-group with radio buttons and vaadin-date-picker. After the fields are filled and send I would like to clear all components and make them empty again. I cannot access the radio-buttons right after the clicking the submit button because of the vaadin-dialog. Could you help me with that?