1. A method for visualising a 3D dental restoration on a 2D image of a mouth of a patient, wherein the method comprises: obtaining a 3D dental model of at least a part of the patient's oral cavity, designing the 3D dental restoration in the 3D dental model, obtaining the 2D image of the mouth of the patient, selecting only a visible portion of the 3D dental restoration, and imaging only the selected visible portion of the 3D dental restoration with the 2D image, wherein the 2D image is not visible at the selected visible portion of the 3D dental restoration.