The most important goal for maintaining instrument sharpness is to preserve the shape and contour of the original instrument. Before you start sharpening, ask these two questions: Are the cutting edges of the instrument straight or curved from the heel to the toe? Is the toe of the instrument pointed or rounded? Once these questions are answered, sharpening can begin with the main goal in mind—maintaining the original shape and contour of the instrument's working end.
Sharpening at the first sign of dullness requires fewer sharpening strokes and less pressure. An extremely dull instrument requires the clinician to use more strokes and exert more pressure, as well as employ a coarser stone that removes more metal. Examine your instruments carefully to see if they are thinning across the face of the blade or from face to back. As an instrument thins in these areas, the risk of breakage increases.
Manual sharpening using the stationary instrument/moving stone method is very effective in preserving the instrument's shape and contour. 1,2 This method permits the clinician to see the shape of the blade's face, thereby making it easier to maintain the contour of the cutting edge. As such, instruments can be more evenly contoured to provide a better fit subgingivally without significantly reducing the instrument strength.3
Two self-instructional guides are available to support effective sharpening technique: It's About Time DVD and manual (Hu-Friedy Mfg Co LLC) and Sharpening Essentials DVD, workbook, and disposable sharpening guide (Edgemate Inc). These programs include video instruction on the correct technique for sharpening curets and scalers along with a step-bystep workbook to enhance practice. In addition, a sharpening stone with two grades of coarseness can be purchased with either study guide.
A variety of automated devices are also available to sharpen instru - ments. When investigating an automated sharpening device, consider whether it will sharpen the lateral sides of the blade or the face. Removing metal from the lateral side of the working end maintains the overall strength of the instrument, which in turn, prolongs its usefulness.2 Instruments with curved blades should also be moved in a pendulum-like motion across the stone to maintain the curvature. Maintaining the original shape of the instrument is as important as ensuring a sharp cutting edge. Finally, follow the directions carefully so as not to alter the design of scaling instruments.
I also recommend trying some of the instruments with the new technology that maintains a sharper edge for a longer period of time. Newer stainless steel alloys and heat treatment processes create a more durable edge that can maintain sharpness for 3 months to 4 months. Newer, diamond- coated instruments never need sharpening, but they are only available in a few designs. While instruments manufactured in the newer technologies may cost more initially, the fact that they last longer may outweigh the initial expense.
1. Nield-Gehrig JS. Fundamentals of Periodontal Instrumentation & Advanced Root Instrumentation. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2000.
2. Marquam BJ. Strategies to improve instrument sharpening. Dent Hyg (Chic). 1988;62:33–38.
3. Green E. Sharpening Curets and Sickle Scalers. 2nd ed. Berkeley, Calif: Praxis; 1972.