Universal Curette

Universal curettes are designed such that each of two parallel, 90 degree, cutting surfaces are formed by the junction of the lateral and facial surfaces that meet at a rounded toe (Figure 8). Close attention to maintain this original shape should be kept in mind during sharpening (Figures 9a-9d).

Figure 8. Cross Section of Universal Curette.
Illustration showing the cross section of a universal curette
Figure 9a. Holding the Curette.
Illustration of proper way to hold a universal curette
With elbows on the work surface, hold the instrument perpendicular to the work surface in the non-dominant hand, braced between the index finger and thumb. The blade to be sharpened will line up with the wrist and the toe of the instrument should point to the operator such that it can be easily visualized at eye level.
Figure 9b. Holding the Sharpening Stone.
Illustration of proper way to hold the sharpening stone
Hold the lubricated side of the sharpening stone in the dominant hand, against the lateral surface of the blade at slightly less than a 30 degree angle to the instrument shank.
Figure 9c. Sharpening Motion.
Animation showing the sharpening motion for a universal curette
Move the stone up and down fluidly starting at the heal third working in a continuous motion through the middle and toe third of the instrument. Sludge and metal filings will begin to form and build up on the stone, and should be wiped away with gauze.
Figure 9d. Sharpening the Toe.
Animation showing the sharpening motion for the toe of a universal curette
Rotate the instrument so that the back side of the toe is parallel to the work surface at eye level and the toe is in the direction of the operator’s thumb. Place stone against the toe at a 60 degree angle to the blade and move it up and down in a consistent motion. Rotate it around the tip to keep the original rounded shape of the tip.

To sharpen the other cutting edge, rotate the instrument between the finger and thumb of the non-dominant hand so that the toe is pointed away from the operator.

Figure 10. Finishing the Instrument.
Animation showing the finishing of a universal curette
Hold the instrument perpendicular to the work surface such that the tip is pointed to the operator. Use the cylindrical or conical stone parallel to the work surface lightly spinning along the face to remove sludge, metal particles and debris.
Table 3. Universal Curette Step-by-Step Summary.
  1. Position the instrument perpendicular to the work surface and rotate the instrument handle left of the vertical plane to align the terminal shank with the vertical plane.
  2. Firmly grasp instrument with non-dominant hand using index finger and thumb.
  3. Compare blade and shank of instrument to be sharpened to a new instrument, decide whether it can endure sharpening and still maintain original design, integrity and strength. Will the terminal shank be so thin that it may snap off during use? Decide to keep or replace instrument.
  4. Point blade tip away from operator to sharpen right cutting edge (point blade tip toward operator to sharpen left cutting edge).
  5. Place stone against lateral surface so the top of the stone is angled 30 degrees right of the terminal shank of the instrument.
  6. Glide stone up and down in a smooth motion beginning with the heel third, progressing to the middle and anterior thirds of the blade.
  7. Wipe away metal filings and sludge.
  8. Do not activate the instrument tip against the stone.
  9. Test sharpness against test strip for “gripping” and sound.
  10. Finish with finishing stone. Using fluid motions to round the toe.