The Importance of Sharpening Your Dental Instruments
Hand instruments tend to be the most abused of all veterinary dental equipment, yet receive the least amount of care and attention beyond cleaning. Many hand instruments, including scalers, curettes, luxating type elevators and elevators require routine sharpening. Over time small particles of metal are worn off of the tip of the instrument, causing the cutting edge to become rounded and dull.Practices often suffer from dull instruments due to lack of time and knowledge of staff members, and in many cases don’t even realize that their instruments need to be sharpened regularly. The problem with dull instruments is that they cannot do their job as quickly or as thoroughly as intended, and cause more trauma to the patient. To help make sharpening a routine, sharpening stones and oil should never be placed in a drawer; they need to remain on the counter to act as a reminder.
Dull scalers and curettes are unable to thoroughly remove the calculus from the teeth, and instead just glide across the surface of the tooth. Dull elevators and luxating type elevators cannot cut the periodontal ligament as efficiently, and cause the practitioner to use excess force and/or remove more buccal bone. Excess force is not only bad for the patient, but can contribute to serious hand, wrist, neck, shoulder, and back pain for the practitioner. Sharp instruments on the other hand save time, improve cutting ability, increase tactile sensitivity, reduce fatigue, and the list goes on…
What You Need to Keep Your Instruments Sharp
There are a variety of tools available to aid in sharpening dental instruments, including power units. The most popular and economical option is the use of sharpening stones. India, Arkansas and ceramic stones are the most common.
The grit of the stone will determine the speed with which an instrument will be sharpened, and the fineness of its edge. A grittier stone is especially useful for very dull instruments and minor instrument repairs. A softer stone will produce a finer edge and can be used as a finishing stone as well as for sharpening slightly dull instruments. Many prefer to use a medium grit India stone followed by a soft Arkansas stone.
Stones are available in a variety of shapes and sizes. A wedge-shaped angled slip stone with one built in conical edge and one straight edge is ideal. A separate conical stone would be required if using a flat stone without a conical edge. The disadvantage of conical stones is that they have a tendency to roll off counters and break. Regardless of shape, medical grade honing oil is required to lubricate and protect India and Arkansas stones. It is applied immediately prior to use. If using a ceramic stone, water is a sufficient lubricant and will help clean microscopic debris off the stone surface. Stones should be cleaned periodically by scrubbing with a stiff bristle brush and mild detergent, rinsed thoroughly then air dried. Most stones can be autoclaved if sterility is desired.
How to Sharpen Your Dental Instruments
Several techniques exist to sharpen scalers and curettes; in some the stone is fixed and the instrument is moved. In others the instrument is fixed and the stone is moved. This is the method of choice of the author as it facilitates a straighter movement on the edge of the instrument. Whichever the technique, the goal is to maintain a 70-80º internal angle between the sole of the working tip and its lateral surface. A sharpening guide can be used to easily find that angle while sharpening.
When dealing with Gracey curettes, the template has to be reset by 20º to accommodate the specific design of these curettes. With a sharpening template folded over the side of a counter, the respective instrument is held against the side of the counter so its distal shank is vertically aligned, with the tip in the lower position and placed at the point where the indicated angles meet. The working tip should be perpendicular to the table, facing the operator. The stone is placed against the blade, on the angle indicated on the template, and is moved upwards and downwards against the blade while maintaining the correct angle. Always end on the downstroke. A quick flick of the conical surface of the stone over the face of the instrument will remove any rough edges. Instruments need to be correctly identified prior to sharpening to ensure that the correct technique is used. You should find our previous blogs about elevators and luxating type elevators, and scalers and curettes helpful for identifying instruments.
Elevators and luxating type elevators also require sharpening. The tips of these instruments are blades that need constant care. To sharpen them, they are held normally but rotated 180º. The index finger now rests against the concave surface of the instrument. The last 0.5 to 1 mm of the tip is placed on the stone with the instrument tip at approximately a 45º angle, and the concave surface facing the wall closest to the operators opposing hand.
A ventral wrist rock motion is performed while the instrument tip is run against the stone, rotating the instrument until the concave surface of the instrument faces the opposite wall. This is then repeated in the opposite direction, without removing the tip from the stone. The result is the creation of a “happy face” on the surface of the stone. Apply a minimal amount of pressure unless attempting to repair a damaged instrument. When finished, the tip of the concave instrument surface can be run against the conical surface of the stone from the narrowest to the thickest edge to remove any knurls. The frequency with which elevators and luxators are sharpened will depend on frequency of use. The average practice should expect to sharpen them at least weekly. If used and maintained properly, they should last several years before requiring replacement.
If veterinary staff members are not confident in their sharpening skills, or are reluctant to sharpen for other reasons you can send dental instruments in to Serona for our professional sharpening service to be regularly to be sharpened. Or check out our CE schedule to see if there is a sharpening seminar coming near you. You can also make a request for a sharpening seminar in your area.
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