There are two cutting edges to a sickle scaler formed where the lateral surfaces meet the facial surface. These two cutting edges meet at the pointed tip. There are two types of sickle scalers. One is straight, which results in a triangular cross section. The other is curved, which results in a cone-shaped cross section. This integrity of form must be maintained during sharpening.
These cutting edges are sharpened by activating a flat stone against the lateral surface of the blade, starting at the heel of the blade, progressing through the middle third and finally to the facial third of the blade using a light fluid up and down motion. After testing for sharpness produces an acceptable result as determined against the test strip, the instrument is ready for finishing to maintain the structural integrity of the facial surface; the facial surface is not sharpened vigorously, only honed to remove any metal fragments.
In the case of the curved sickle scaler, holding the instrument handle perpendicular to the work surface with the tip toward the operator, place the conical stone horizontally on the instrument face and gently rotate the stone from heel-to-middle-to-tip. Use a similar grasp for the straight sickle scaler; perpendicular to the work surface with the tip toward the operator, use the flat stone on the instrument face and gently moving the stone horizontally across the face (Figures 6a‑6c). The intent is to remove debris and wire edges, not to sharpen the face.
After sharpness testing produces an acceptable result, the instrument is ready for finishing (Figure 7).