FIG. 4.

Photographs of the rotary drill loaded with water. The diameter of the spherical part of the drill (the drill head) is 2.3 mm. (a) Magnified image of the drill head loaded with water operating in the experiments. Scale bar: 1 mm. The image is taken from video 4(a). (b) The far-field photo of the drill operating on a dental mannequin installed in a dental chair in the experiments in the dental clinic. This still image is taken from video 4(b). Scale bar: 1 cm. Multimedia views: https://doi.org/10.1063/5.0021476.3Download video file ^{(20.6MB, avi)} DOI: 10.1063/5.0021476.3; https://doi.org/10.1063/5.0021476.4Download video file ^{(4.1MB, mp4)} DOI: 10.1063/5.0021476.4