Sharpening of Periodontal Instruments

During periodontal surgical procedures, it is imperative to have sharp instruments. A sharp, well maintained instrument will insure that the surgery is performed with the utmost care. Clean dissection with properly cared for instruments will not only decrease surgical time but increase post operative healing as well.

Objective and Evaluation

The objective of sharpening periodontal instruments is to restore a fine, thin linear cutting edge. This can be done by sharpening stones, mounted rotary stones, or unmounted stones. When dull instrument is held under a light, the rounded surface of cutting edge reflects back. A sharp instrument will not reflect light. Tactile evaluation of sharpness should be performed by drawing instrument across acrylic rod such as a sharpening stick or saliva ejector.

Principles of Sharpening:

The first principle of instrument sharpening is to choose a suitable stone. Stones are graded by their level of coarseness. Experienced operators are more likely to use a coarse stone as it hastens the procedure. Those who are new to sharpening instruments may want to consider a smooth stone to minimize error. Always use a sterilized sharpening stone as bacteria can be transferred from a dirty instrument onto other surfaces. Once a sterilized stone is chosen, place the instrument on the stone and establish a proper angle.

This angle is normally determined by the manufactures' recommendation. Maintain a stable, firm grasp of both instrument and sharpening stone while avoiding excessive pressure. Begin to sharpen the stone with long, smooth strokes. Sharpen the instrument with several strokes then test the sharpness with either an acrylic rod or saliva ejector. Desired sharpness is generally operator dependent. Avoid formation of a wire edge as this can increase the possibility of instrument fracture. Always lubricate the stone during sharpening to preserve the life of the instrument.

Specific Instrument Sharpening Techniques:

When sharpening universal curettes, be sure to maintain 70 to 80 degree angle of blade. The stone should be placed at 100 to 110 degrees to the lateral surface. The face of the blade is generally sharpened with a hand held cylindrical or cone shaped stone.For area specific curettes such as Gracey scalers, apply the stone to the lateral surface so an angle of 100 to 110 degrees is formed. There is no change to technique for extended shank, mini, and After-5 curettes. Sickle scalers should also have an angle between the face and blade of 100 to 110 degrees.

Chisels and hoes follow a different technique. With the entire surface of bevel contacting the stone use a 45 degree angle with moderate steady pressure. A pull motion is used with long and steady strokes. A back action chisel is sharpened with the same technique however with be mindful that some back action chisels have an addition angle to account for.

Periodontal knives such as an Orban or Kirkland are difficult to sharpen. It is important to know that only the bevel on the back surface needs to be ground. Using a pull motion, draw the blade across a stationary flat sharpening stone with long steady strokes until a desired sharpness is reached. Interproximal knives should only have the bevel on the back surface sharpened. It is imperative to monitor the thickness of the blade after sharpening as periodontal knives tend to fracture quite easily during surgery.