A device for sharpening one or more cutting edges of a dental curette has a base support with a frame articulated thereon, and at least one sharpening guide. The frame supports a grinding wheel rotationally driven by a motor and a sharpening guide support intended to receive the sharpening guide(s). The guide includes at least one indicator in the form of a line marked on the guide, whose angle with the horizontal being between 10° and 50° but preferably equal to 10°, 20° or 30° and corresponding to the type of dental curette to be sharpened. The sharpening guide(s) can move with respect to the support, and the support and/or the guide include(s) indexing and positioning elements determining indexing positions of the guide on the support, each indexing position corresponding to a different indicator. A method of sharpening one or more cutting edges, and a sharpening guide are described.