SHARPENING OF PERIODONTAL INSTRUMENTS
efficient and effective root planing and scaling, it is essential that
curettes and hand scalers are sharpend correctly and frequently. The objective
of sharpening is to produce a sharp cutting edge without changing the original
design of the instrument.
Many dentists report
being put off the process of sharpening their periodontal instruments because
textbooks often go into a great deal of detail about oiling the sharpening
stone as a necessary part of the sharpening process. This, of course, implies
that the instrument is not going to be inserted into the patient's mouth
without further scrubbing and sterilisation. And yet we know that the sterilisation
process itself will blunt the sharpened edge. Therefore, in practical terms,
it is advisable to integrate the sharpening of your periodontal instruments
at chairside as part of a patient's periodontal visit.
dull very quickly during root-planing procedures, and it is necessary to
resharpen them at frequent intervals over the length of an appointment.
The sharpening stone should be sterilised, but it is not necessary to use
a lubricant if instruments are sharpened regularly.
Choice of Stones:
are manufactured in a wide range of shapes and materials. However, it appears
that the dental supply houses only stock a very limited range, and therefore
you may feel that your choice is restricted to those few. It is important
to use a stone that is large enough for you to secure a firm grip, to reduce
the chance of accidental slippage and trauma to your fingers during sharpening.
Recommended stones for sharpening both Gracey and Universal style curettes
I. No6. India wedge
shape (SS6) (Hu-Friedy) 4 1/2" x 1 7/8" x 3/8" down to 1/8" thick.
This stone is good for sharpening
up extremely dull instruments, but is too coarse for everyday maintenance
of your curettes.
2. No 6A. Arkansas
wedge shape (SSG6A) (Hu-Friedy) 4" x 1 7/8" x 3/8' - 1/8"
This stone is made for a
finer grit material, and is suitable for regular sharpening of curettes.
3. No299. ArkansasConical
(SS299) (Hu-Friedy) 3 1/2" x 5/16" base.
This is a hard stone with
a super-fine grit. Suitable for sharpening the facial surfaces of curettes.
Principles of sharpening
1. Learn how to detect
a blunt instrument. With experience, you canjudge when to resharpen an
instrument during root-planing through tactile feedback. A dull cutting
edge will require the use of greater lateral forces against the root, and
will crush or burnish the calculus rather than removing it cleanly. A visual
cue to an instrument's sharpness is that a dull instrument will reflect
light along the line of it's cutting edge, whereas a sharp cutting edge
will not reflect light. Sharpen at the first sign of dullness.
Understand the design of your periodontal instrument (see Practice Information
Sheet No 6). It is important to retain the curvature of the blade and the
angle of the cutting edge. The angle between the face of the blade and
the lateral surface of any curette is 70-80 Degrees. The best way to judge
this angle is to place the sharpening stone to the lateral surface of the
curette so that the angle between the face of the blade and the stone is
90 Degrees. Next, open this angle 10-20 Degrees by rotating the stone laterally.
Maintain this angle during sharpening. Using short up and down strokes
with consistent light pressure, sharpen the entire blade from shank end
to toe. When approaching the toe, sharpen around it to prevent it from
4. Only the cutting
edge of Gracey curettes should be sharpened. The curvature of the cutting
edge of the Gracey curette blade from shank to toe needs to be preserved
during sharpening. If the stone is kept in one place for too many strokes,
the blade will be flattened. This can be avoided by turning the stone slowly
as you sharpen with up and down strokes.
5. Avoid excessive
pressure that will lead to unnecessary shortening of the life of the instrument.
6. Avoid formation
ofa 'tvire edge", which occurs when the direction of the sharpening stroke
is away from, rather than into or towards the cutting edge.
7. The face of the
blade can be sharpened using a cone-shaped stone applied to the face of
the blade and moved with a side-to-side, back and forth motion. This procedure
should be performed infrequently, as it weakens the blade by narrowing
it from face to back.
package well-sharpened fine instruments separately from newer, broader
instruments. The use of fine instruments is often necessary during the
maintenance phase of periodontal care in order to gain access to a residual
pocket, particularly if there has been a favourable gingival response with
firming up of the tissue consistency. Broad-bladed sharp instruments are
ideal to remove heavier subgingival calculus deposits, particularly if
the surrounding tissues are inflamed.
If you need further guidance
on sharpening of periodontal instruments, an excellent text is:
Pattison G, Pattison AM.
(1992) Periodontal instrumentation - a clinical manual. 2nd edition. Reston
Publishing Company, Inc. Virginia, USA.
This material has been compiled
with the assistance of Dr Louise Brown, Lecturer in Periodontics at the
University of Melbourne.