2. Left-handers
A Timely Approach to Instrument Sharpening
Sickle Scalers & Gracey Curettes
Universal Curettes
Take Time for Tips & Toes
Sickle Scalers & Universal Curettes Gracey Curettes
1 Position instrument vertically with blade 1 Position instrument vertically with blade
to be sharpened at 6:00. to be sharpened at 6:00.
2 Stabilize entire length of instrument with 2 Check the blade identification number:
a firm grasp. Aim the toe of all EVEN-numbered
3 Balance upper shank with index finger or Graceys toward you.
thumb. Direct the toe of all ODD-numbered
4 Point tip or toe of blade toward you to Graceys away from you.
sharpen left cutting edge and away from 3 Stabilize entire length of instrument with
you to sharpen opposite cutting edge. a firm grasp.
5 Hold terminal shank at 12:00. 4 Counterbalance top shank with index
6 Place side of stone against left lateral finger or thumb.
surface. 5 Tilt terminal shank toward 1:00.
7 Tilt top of stone toward, not beyond, 6 Hold stone against left lateral surface and
11:00. tilt toward 11:00.
8 Move stone up and down in three distinct 7 Move stone up and down in three distinct
sections of the blade: heel third, middle sections of the blade: heel third, middle
third, anterior third. third, and anterior third.
9 For curettes, rotate the instrument blade 8 Repeat steps #9, 10, and 11 to “round”
toward 9:00. the toe.
10 Aim the stone at 10:00.
11 Use continuous and overlapping up-and-
down motions to “round” the toe.
SDVD

3. Preface
The method for sharpening periodontal scalers and curettes described in this
manual is based upon a teaching strategy designed and developed by:
Sherry Burns, R.D.H., M.S.
Author and Creator, It’s About Time
and
Educational Consultant
Hu-Friedy Mfg. Co., Inc.
Hu-Friedy’s Self-Study Manual for Sharpening Scalers and Curettes is approved
by the Department of Continuing Education, University of Missouri-Kansas
City School of Dentistry for Continuing Dental Education credit. This Continuing
Dental Education Activity was planned and produced in accordance with the
ADA/CERP standards.
This program is approved for two Continuing Education credits (two
Contact Hours) when successful completion of the post-test is submitted.
The views and techniques expressed in this self-study program do not
necessarily reflect the views or opinions of the University of Missouri-Kansas
City School of Dentistry.
©2009 Hu-Friedy Mfg. Co., Inc.
1

4. Time to sharpen again...
This self-study manual describes a new approach to sharpening periodontal Why Sharpen:
scalers and curettes which will put you on the cutting edge in no time. The Instruments should be kept sharp and true to their original design. Dental
traditional techniques have relied upon “degrees of angulation” to achieve procedures are most effective when using sharp instruments because they
the correct position of the stone in relation to the blade while sharpening. reduce fatigue, improve deposit removal, save time, improve tactile sensitivi-
This alternative method utilizes the simple visual imagery of the hands of the ty, and minimize patient discomfort.
clock to establish the correct positions while holding the instrument station-
When to Sharpen:
ary and moving the stone.
Repeated use of an instrument wears away minute particles of metal from the
This manual is designed to be used independently or in combination
blade causing the cutting edge to take on a rounded shape resulting in a dull,
with the videotape “It’s About Time To Get On The Cutting Edge.” The sim-
ineffective blade.
plified approach to sharpening and testing the Sickle Scaler, Universal
When the blade is dull, the clinician loses the ability to “feel” the
Curette, and Gracey Curette is thoroughly described and illustrated.
sharp edge “grabbing” onto a surface. It may then seem that the blade is
Participants may receive two hours of Continuing Dental Education Credit
“sliding” over the surface or deposit which causes the clinician to work harder
upon successful completion of the post-test included in this manual and sub-
to remove deposits. This could result in burnishing rather than removing the
mission to the University of Missouri-Kansas City (see insert).
deposit.
Learning Objectives: For best results, instruments should be sharpened lightly after each use
Upon completion of this self-instructional manual, the participant will be able to: rather than reconditioning or recontouring after repeated use. Remember that
1. List the benefits achieved when utilizing scalers and curettes with sharp consistent sharpening on a regular basis is preferable to an extensive amount
cutting edges. of sharpening or reconditioning all at once.
2. Distinguish a “dull“ cutting edge from a “sharp” edge. How to Determine Sharpness:
The hard Plastic Test Stick can be used to determine
3. Characterize the Arkansas Stone, the India Stone, and the Ceramic Stone the sharpness of the instrument. It is designed specif-
according to: ically for this purpose. When the proper testing pro-
a. Shape cedure is followed, a sharp edge will bite into or
b. Abrasive grit size “grab” the test stick and produce a metallic clicking A dull blade reflects light
c. Preferred lubricant sound. A dull edge will slip or slide over the surface of
along the cutting edge.
4. Describe how the traditional “degrees of angulation” correspond with the test stick.
the clock positions in this strategy. Another way to test the sharpness of an instru-
5. Identify the essential grasp of both the instrument and the sharpening ment is to inspect the blade visually. Hold the instru-
stone as defined in this technique. ment under a light (and if possible, under magnifica-
tion) and rotate the instrument until the edge is facing
6. Describe the sharpening procedure for Sickle Scalers, Universal Curettes, the light. A dull cutting edge will reflect light when it A sharp cutting edge
does not reflect light.
and Gracey Curettes as outlined in this technique. has become rounded from use.
7. Define the procedure for determining when a “sharpened” blade actually is How to Compare:
“sharp”. Use new instruments (master samples) to compare with the dullAinstruments.
A master set will provide the original pattern for maintaining the blade design
and proper contour of the cutting edges.
When to Replace Instruments:
Throughly inspect each blade after sharpening to determine if the original
shape has been significantly altered, or if the strength and integrity has been
compromised.
2 3

5. Time to Get Started...
Sharpening Stones Coarser stones are intended mainly for recontouring and should not be used
for light sharpening. Using a coarser stone may remove too much metal from
There are several types of sharpening stones. The following are recommend-
the surface of the blade. If a coarser stone is used it should be followed by a
ed for frequent honing and sharpening of the blade.
finer grit stone.
Compositions
Stone Care
Arkansas Stone- The Arkansas Stone is a natural stone with a fine grit. Oil
After each use, stones should be wiped with a clean cloth to remove metal
lubrication is suggested when using this stone, however it can be used dry as
particles. They can be scrubbed and/or ultrasonically cleaned to remove any
well. The oil serves as a vehicle to float the metal particles as they are ground
lubricant before sterilization. Alternate the areas used for sharpening to pre-
away from the blade and prevents those shavings from becoming imbedded
vent “grooving” in the stone.
in the stone. The buildup of these shavings in the oil is referred to as “sludge.”
Stone Lubrication
Ceramic Stone- The Ceramic Stone is a hard synthetic stone available in Oil lubrication is preferred for Arkansas and India Stones. Ceramic Stones may
either fine or medium grit. This stone is excellent for routine sharpening of be lubricated with water or used dry.
dental instruments and uses water as lubrication. When sharpening with a
Ceramic Stone there will be an accumulation of metal filings rather than Work Area
“sludge.” Your work area should be spacious and well-lit. The table should be steady
and high enough so that you can place your elbow on the table and hold the
India Stone- The India Stone is a synthetic stone composed of aluminum instrument at eye level.
oxide crystals with a fine or medium grit. Oil lubrication is required when
sharpening with this stone. Other Materials
Shapes Before beginning the sharpening process, assemble the required materials. In
Conical Stone- The conical stone is an Arkansas Stone used for finishing or addition to the instruments to be sharpened and the proper sharpening
removing any wire edges after sharpening. stones, you will need the following items:
1. Safety Glasses- required when sharpening. Safety glasses should cover
Cylindrical Stone- The cylindrical stone can be an Arkansas or Ceramic the eyes completely and have side panels for maximum protection.
Stone and is used for finishing or removing any wire edges after sharpening.
2. Gloves- should fit comfortably.
Flat Stone- The flat stone typically is rectangular but comes in various sizes. 3. Cotton Tipped Applicators- to spread oil or water lubrication.
It can be an Arkansas, Ceramic or India Stone. 4. Gauze- to wipe away sludge or shavings from the surface of the stone
and the blade.
Wedge Stone- The wedge stone is a rectangular-shaped stone with rounded
edges and commonly is an Arkansas or India Stone. 5. Magnifying Glass- to view the blade.
6. Plastic Test Stick- to test the cutting edge for sharpness.
Stone Grits
7. Clock- to determine the proper positioning of the instrument, stone and
There are many grits available for the sharpening stones. Be sure to use the
test stick. You may use the clock drawing provided in this manual.
proper grit for sharpening dental instruments. The grits recommended for
light or frequent sharpening are:
Arkansas - Fine
Ceramic - Fine or Medium
India - Fine or Medium
4 5

6. Time to Get on the Cutting Edge...
basic principles of sharpening
Anatomy of an Instrument Instrument Grasp
All scalers and curettes have three common components: Your grasp on the instrument is important throughout
the sharpening process. Hold the instrument in your
Handle- for grasping the instrument. nondominant hand with a secure palm grasp. Brace
your index finger or thumb near the top of the instru-
Shank- connects the handle to the working end and allows the working end ment to counterbalance the pressure caused by grinding
to adapt to tooth surfaces. the lower blade. Using the clock as a guide, hold the
instrument vertically with the blade to be sharpened at
Working End- consists of a blade that has one or two cutting edges. six o’clock.
Stone Grasp
Grasp the lower half of the stone in your dominant
GRACEY 1/2
hand. Hold the stone upright at twelve o’clock by
placing your thumb on the edge toward you and
Instrument Labeling your fingers on the edge away from you. This grasp
When the design name and number are stamped along the length stabilizes the stone and assists in maintaining a con-
of the handle, each working end is identified by the number closest sistent vertical motion. Move your entire arm in a
to it. If the design name and number are stamped around the instru- fluid up-and-down motion when sharpening.
ment handle, the first number (on the left) identifies the working
Stone Lubrication
end at the top and the second number identifies the working end
G1/2 When using an Arkansas or India Stone, spread oil on the entire surface of
at the bottom of the handle.
the stone. When using the Ceramic Stone, use water lubrication on the sur-
Terminal Shank face of the stone.
Working The terminal shank is the area of the
End instrument between the blade and the
first angle.This is the key feature for each
scaler or curette. Proper alignment of the
terminal shank will automatically place
Terminal the blade in the correct position for sharp-
Shank
ening when using the clock approach.
Functional
Shank
Degrees of Angulation
The traditional reference to “degrees of angulation”
will be simplified by using the analogy of the hands
of a clock. (See page 23 for more details). These
approaches are complementary and appropriate for
learning sharpening techniques (refer to page 23).
6 7

7. The Sickle Scaler
Design of the Sickle Scaler cutting edge
face
Sharpening the Opposite Cutting Edge:
The sickle scaler has two cutting edges which tip
90°
Rotate the instrument so that the tip is pointed away from you. Maintain the
back
are formed by the junction of the facial surface cutting edge
lateral surface secure palm grasp and again brace the top shank with your index finger or
with the two lateral surfaces converging to a thumb with the terminal shank at twelve o’clock. Place the stone toward one
pointed tip. This triangular cross section results o’clock. Repeat the grinding process maintaining the clock position. Then
in an almost pointed back. The facial surface of wipe the sludge or metal filings from the surface of the blade with the gauze.
the blade is positioned at a 90 degree angle to tip
cutting edge
the terminal shank. This is important to note
face
90° Finishing the Curved Sickle Scaler:
because it affects the positioning of the stone
cutting edge back With the tip toward you hold the terminal shank at twelve o’clock. Place the
lateral surface
and instrument while sharpening. conical stone on the face of the instrument with the stone pointed at three
When sharpening either the straight or curved sickle scaler you will o’clock and nine o’clock. Lightly rotate the conical stone along the face from
restore the cutting edges by grinding against the lateral surfaces of the blade the heel to the tip to remove any wire edges. The stone can be used either
and finishing the facial surface. Excessive sharpening of the facial surface is lubricated or dry.
not recommended because it will weaken the blade. Finishing the Straight Sickle Scaler:
The position of the stone, instrument and test stick will vary depend- With the tip toward you hold the terminal shank at twelve o’clock. Place a
ing upon whether you are right-handed or left-handed. For the remainder of flat stone on the facial surface of the instrument at the three o’clock and nine
this manual, each sharpening and testing procedure has been divided into o’clock position. Lightly move the stone from side to side to remove any wire
two sections: right-handed and left-handed. edges.
Sharpening the Sickle Scaler · For Right-handers Sharpening the Sickle Scaler · For Left-handers
Instrument Position: Instrument Position:
Hold the instrument vertically in your nondominant hand. Hold the instrument vertically in your nondominant
The blade to be sharpened will be at the bottom with hand. The blade to be sharpened will be at the bottom
the tip pointed toward you. Brace the top shank with with the tip pointed toward you. Brace the top shank
your index finger or thumb and place your elbow with your index finger or thumb and place your
directly in front of you on the table. Now position the elbow directly in front of you on the table. Now posi-
terminal shank at twelve o’clock. tion the terminal shank at twelve o’clock.
Stone Position: Stone Position:
Place the lubricated side of the Place the lubricated side of the
stone against the right lateral surface stone against the left lateral sur-
of the blade. Initially place the stone at face of the blade. Initially place the stone at twelve
twelve o’clock and then tilt the top of the stone to o’clock and then tilt toward eleven o’clock.
slightly less than one o’clock.
Stone Movement:
Stone Movement: Initiate grinding in a fluid up-and-down motion.
Initiate grinding in a fluid up-and-down motion. Start Start at the heel third of the blade and continue to
at the heel third of the blade and continue to the the middle third and finally to the tip third. You
middle third and finally to the tip third. You should see a buildup of sludge should see a buildup of sludge along the entire facial surface of the blade. If
along the entire facial surface of the blade. If you are using a Ceramic Stone you are using a Ceramic Stone you will see a buildup of metal filings instead
you will see a buildup of metal filings instead of sludge. Wipe the sludge or of sludge. Wipe the sludge or metal filings from the surface of the blade and
metal filings from the surface of the blade and the stone with the gauze. the stone with the gauze.
8 9

8. The Sickle Scaler It’s Time to Test...
Sharpening the Opposite Cutting Edge:
Rotate the instrument so that the tip is pointed away from you. Maintain the Testing the Sickle Scaler
secure palm grasp and again brace the top shank with your index finger or
thumb with the terminal shank at twelve o’clock. Place the stone toward Test Stick Position:
eleven o’clock. Repeat the grinding process maintaining the clock position. To test the cutting edge hold the test stick in your non-
Then wipe the sludge or metal filings from the surface of the blade with the dominant hand between your thumb and index finger
gauze. about one half inch from the top of the stick. The position
for the test stick is twelve o’clock.
Finishing the Curved Sickle Scaler:
With the tip toward you hold the terminal shank at twelve o’clock. Place the Instrument Position for Right-handers:
conical stone on the face of the instrument with the stone pointed at three In your dominant hand, hold the instrument with a
o’clock and nine o’clock. Lightly rotate the conical stone along the face from modified pen grasp. Bring the instrument around
the heel to the tip to remove any wire edges. The stone can be used either behind the test stick with the tip pointed toward you.
lubricated or dry. Place the cutting edge to be tested against the left side
of the test stick and fulcrum on the right side. Be sure
Finishing the Straight Sickle Scaler: not to rest your ring finger on the top of the test stick.
With the tip toward you hold the terminal shank at twelve o’clock. Place a Tilt the terminal shank toward one o’clock which is rep-
flat stone on the facial surface of the instrument at the three o’clock and nine resentative of the same angle that is used for scaling.
o’clock position. Lightly move the stone from side to side to remove any wire
edges. Instrument Position for Left-handers:
In your dominant hand, hold the instrument with a mod-
ified pen grasp. Bring the instrument around behind the
test stick with the tip pointed toward you. Place the cut-
ting edge to be tested against the right side of the test
stick and fulcrum on the left side. Be sure not to rest
your ring finger on the top of the test stick. Tilt the ter-
minal shank toward eleven o’clock which is representa-
tive of the same angle that is used for scaling.
Testing the Cutting Edge:
Press the cutting edge laterally into the test stick and
release. Test the entire length of the blade. A sharp edge
will bite into or grab the test stick but will not slide over
the side of the test stick. When the edge is removed, it
produces a metallic sound. If the cutting edge slides
over the side of the test stick it may indicate the blade is
still dull, the terminal shank is not positioned correctly, or
the stone was not positioned properly while grinding.
Shaving the test stick will dull the blade.
Testing the Opposite Cutting Edge:
To test the opposite cutting edge rotate the tip away from you positioning
the terminal shank in front of the test stick and repeat the same process.
Be sure to test the entire length of the blade.
10 11

9. The Universal Curette
Design of the Universal Curette Rounding the Toe:
toe
cutting edge
To maintain the rounded shape of the curette toe,
The Universal Curette blade has two parallel cut- face
rotate the instrument so that the toe is pointing at
cutting edge
ting edges that meet at a rounded toe. The cut- back
lateral surface 90° three o’clock. Position the stone at three o’clock and
ting edges of the curette are formed at the junc- tilt upward toward the two o’clock position. Move
tion of the lateral surfaces with the facial surface. the stone in a consistent up-and-down motion, over-
The facial surface of the blade is positioned at a 90 degree angle to the ter- lapping the strokes and rotating around the toe to
minal shank. This is important to note because it affects the positioning of the maintain the rounded shape.
stone and instrument while sharpening.
Finishing:
Sharpening the Universal Curette · For Right-handers Hold the terminal shank at twelve o’clock with the toe
pointed toward you. Position the Conical or cylindrical
Instrument Position: stone along the face of the instrument at three o’clock
Hold the instrument vertically in your nondominant hand. and nine o’clock. Lightly rotate the stone along the face
The blade to be sharpened will be at the bottom with from the heel to the toe to remove any wire edges.
the toe pointed toward you. Brace the top shank with Repeat the sharpening process for the other end
your index finger or thumb and place your elbow of the instrument.
directly in front of you on the table. Now position the
terminal shank at twelve o’clock. Sharpening the Universal Curette · For Left-handers
Stone Position: Instrument Position:
Place the lubricated side of the Hold the instrument vertically in your nondominant
stone against the lateral surface of hand. The blade to be sharpened will be at the bottom
the blade. Initially place the stone at twelve o’clock with the toe pointed toward you. Brace the top shank
and then tilt the top of the stone to slightly less than with your index finger or thumb and place your elbow
one o’clock. directly in front of you on the table. Now position the
Stone Movement: terminal shank at twelve o’clock.
Initiate grinding in a fluid up-and-down motion Stone Position:
using your entire arm. Start at the heel third of the Place the lubricated side of the
blade then continue to the middle third and finally the toe third. Remember stone against the lateral surface of
to maintain a continuous up-and-down motion as you grind using long the blade. Initially place the stone at twelve o’clock
strokes with moderate pressure. You should see a buildup of sludge along the and then tilt the top of the stone toward eleven
entire facial surface of the blade. If you are using a Ceramic Stone you will o’clock.
see a buildup of metal filings instead of sludge. Wipe the sludge or metal fil-
ings from the surface of the blade and stone with the gauze. Stone Movement:
Initiate grinding in a fluid up-and-down motion
Sharpening the Opposite Cutting Edge: using your entire arm. Start at the heel third of the
Rotate the instrument so that the toe is pointed away blade then continue to the middle third and finally the toe third. Remember
from you. Maintain the secure palm grasp and again to maintain a continuous up-and-down motion as you grind using long
brace the top shank with your index finger or thumb. strokes with moderate pressure. You should see a buildup of sludge along the
Repeat the grinding process keeping the terminal shank entire facial surface of the blade. If you are using a Ceramic Stone you will
at twelve o’clock and the top of the stone positioned see a buildup of metal filings instead of sludge. Wipe the sludge or metal fil-
slightly toward one o’clock. ings from the surface of the blade and stone with the gauze.
13

10. The Universal Curette It’s Time to Test...
Sharpening the Opposite Cutting Edge:
Rotate the instrument so that the toe is pointed away Testing the Universal Curette
from you. Maintain the secure palm grasp and again
brace the top shank with your index finger or thumb. Test Stick Position:
Repeat the grinding process keeping the terminal shank To test the cutting edge hold the test stick in your
at twelve o’clock and the top of the stone toward eleven nondominant hand between your thumb and index
o’clock. finger about one half inch from the top of the stick. The
Rounding the Toe: position for the test stick is twelve o’clock.
To maintain the rounded Instrument Position for Right-handers:
shape of the curette toe, rotate the instrument so In your dominant hand, hold the instrument with a mod-
that the toe is pointing at nine o’clock. Position the ified pen grasp. Bring the instrument around behind the
stone at nine o’clock and tilt upward toward the test stick with the toe pointed toward you. Place the cut-
ten o’clock position. Move the stone in a consis- ting edge to be tested against the left side of the test
tent up-and-down motion, overlapping the strokes stick and fulcrum on the right side. Tilt the terminal
and rotating around the toe to maintain the shank toward one o’clock. Testing must be done at
rounded shape. exactly the same angle that the blade is used for scaling.
Finishing: Instrument Position for Left-handers:
Hold the terminal shank at twelve o’clock with the toe In your dominant hand, hold the instrument with a
pointed toward you. Position the conical or cylindrical modified pen grasp. Bring the instrument around
stone along the face of the instrument at three o’clock behind the test stick with the toe pointed toward you.
and nine o’clock. Lightly rotate the stone along the face Place the cutting edge to be tested against the right
from the heel to the toe to remove any wire edges. side of the test stick and fulcrum on the left side. Tilt
Repeat the sharpening process for the other end the terminal shank toward eleven o’clock. Testing must
of the instrument. be done at exactly the same angle that the blade is
used for scaling.
Testing the Cutting Edge:
Press the cutting edge laterally into the test stick and release. Test the
entire length of the blade. A sharp edge will bite into or grab the test stick
but will not slide over the side of the test stick. When the edge is removed,
it produces a metallic sound. If the cutting edge slides over the side of the
test stick it may indicate the blade is still dull, the terminal shank is not
positioned correctly, or the stone has not been positioned properly while
grinding. Shaving the test stick will dull the blade.
Testing the Opposite Cutting Edge:
To test the opposite cutting edge rotate the toe away from you position-
ing the terminal shank in front of the test stick and repeat the same
process. Be sure to test the entire length of the blade.
Repeat the testing process for the other end of the instrument.
14 15

11. The Gracey Curette
Design of the Gracey Curette Stone Position:
Position the stone against the right lateral surface at
The Gracey Curette differs from the Universal twelve o’clock and tilt the top of the stone to slightly
Curette and Sickle Scaler. The facial surface is toe
less than one o’clock.
face
angled downward at a 70 degree angle creating cutting edge
only one functional edge to be sharpened, the back
70°
Stone Movement:
lateral surface
lower edge. The cutting edge on a Gracey instru- Initiate grinding in a fluid up-and-down motion starting
ment is not curved to one side as it may seem but at the heel third of the blade then continuing to the
is straight as it comes forward off the shank. This is important to remember middle third and finally the toe third. Failing to sharpen
when sharpening this instrument in order to maintain the original blade design. the entire length of the blade is a common sharpening
The Gracey instruments are paired designs and the blades are identified error. Be sure to use a consistent movement along the entire blade. You
by a number. Each double-ended Gracey has an odd and an even number should see a buildup of sludge along the entire facial surface of the blade. If
which identifies the blades. For example, the Gracey 11/12 has the 11 blade you are using a Ceramic Stone you will see a buildup of metal filings instead
on one end and the 12 blade on the opposite end. of sludge.
Blade Positioning for Right-handers: Rounding the Toe:
For all odd-numbered Gracey blades, point the toe of the blade toward you Maintain the terminal shank at the eleven o’clock
when sharpening. For all even-numbered Gracey blades, point the toe of the position. Slowly rotate the instrument so that the toe
blade away from you. This positions the lower cutting edge on the right side is pointing at three o’clock. The face of the instru-
of the blade. ment should be parallel to the table surface. Position
the stone at three o’clock and tilt the stone upward
Blade Positioning for Left-handers: to the two o’clock position. Move the stone in a con-
For all odd-numbered Gracey blades, point the toe of the blade away from sistent motion, overlapping the strokes and rotating
you. For all even-numbered blades, point the toe of the blade toward you. around the toe to maintain the rounded shape.
This positions the lower cutting edge on the left side of the blade. Wipe the sludge or metal filings from the surface of
the blade and stone with the gauze.
Sharpening the Gracey Curette · For Right-handers
Finishing:
Instrument Position – Odd-Numbered Blade: Hold the terminal shank at eleven o’clock with the toe pointed toward you.
Begin with the odd-numbered end of the Gracey. Hold the
Position the conical or cylindrical stone along the face of the instrument at
instrument in your nondominant hand vertically with a firm
three o’clock and nine o’clock. Lightly rotate the stone along the face from
palm grasp so that the blade to be sharpened will be at
the heel to the toe to remove any wire edges.
the bottom with the toe pointed toward you. Focus
only on the terminal shank of the instrument and tilt
the terminal shank toward eleven o’clock. Remember
Sharpening the Even-Numbered Blade:
to brace the top shank of the instrument with your Instrument Position:
index finger or thumb. Position the instrument so that the even-numbered blade is at the bottom
and the toe is pointed away from you. Maintain the secure palm grasp and
again brace the top shank with your index finger or thumb. Repeat the grinding
process keeping the terminal shank at eleven o’clock.
16 17

12. The Gracey Curette
Rounding the Toe: Rounding the Toe:
Rotate the instrument so that the toe is pointing at three o’clock. The face of Maintain the terminal shank at the one o’clock posi-
the instrument should be parallel to the table surface. Position the stone at tion. Rotate the instrument so that the toe is point-
three o’clock and tilt the stone upward to the two o’clock position. Move the ing at nine o’clock. The face of the instrument
stone in a consistent motion, overlapping the strokes and rotating around the should be parallel to the table surface. Position the
toe to maintain the rounded shape. Wipe the sludge or metal filings from the stone at nine o’clock and tilt the stone upward to
surface of the blade and stone with the gauze. the ten o’clock position. Move the stone in a consis-
tent motion, overlapping the strokes and rotating
Finishing:
around the toe to maintain the rounded shape.
With the toe of the even-numbered Gracey blade pointed toward you, hold the
Wipe the sludge or metal filings from the surface of
terminal shank at one o’clock. Position the conical or cylindrical stone along the
the blade and stone with the gauze.
face of the instrument at three o’clock and nine o’clock. Lightly rotate the stone
along the face from the heel to the toe to remove any wire edges. Finishing:
With the toe pointed toward you, hold the terminal shank at one o’clock.
Sharpening the Gracey Curette · For Left-handers Position the conical or cylindrical stone along the face of the instrument at
Instrument Position – Even-Numbered Blade: three o’clock and nine o’clock. Lightly rotate the stone along the face from
Begin with the even-numbered end of the Gracey. Hold the the heel to the toe to remove any wire edges.
instrument vertically in your nondominant hand with a
firm palm grasp so that the blade to be sharpened will Sharpening the Odd-Numbered Blade:
be at the bottom with the toe pointed toward you. Instrument Position:
Focus only on the terminal shank of the instrument Position the instrument so that the odd-numbered blade is at the bottom and
and tilt the terminal shank toward one o’clock. the toe is pointed away from you. Maintain the secure palm grasp and again
Remember to brace the top shank of the instrument brace the top shank with your index finger or thumb. Repeat the grinding
with your index finger or thumb. process keeping the terminal shank at one o’clock.
Stone Position: Rounding the Toe:
Position the stone against the left Rotate the instrument so that the toe is pointing at nine o’clock. The face of
lateral surface at twelve o’clock and tilt the instrument should be parallel to the table surface. Position the stone at
the top of the stone to toward eleven o’clock. nine o’clock and tilt the stone upward to the ten o’clock position. Move the
Stone Movement: stone in a consistent motion, overlapping the strokes and rotating around the
Initiate grinding in a fluid up-and-down motion toe to maintain the rounded shape. Wipe the sludge or metal filings from the
starting at the heel third of the blade then continu- surface of the blade and stone with the gauze.
ing to the middle third and finally the toe third. Finishing:
Failing to sharpen the entire length of the blade is a With the toe pointed toward you, hold the terminal shank at eleven o’clock.
common sharpening error. Be sure to use a consis- Position the conical or cylindrical stone along the face of the instrument at
tent movement along the entire blade. You should see a buildup of sludge three o’clock and nine o’clock. Lightly rotate the stone along the face from
along the entire facial surface of the blade. If you are using a Ceramic Stone the heel to the toe to remove any wire edges.
you will see a buildup of metal filings instead of sludge.
18 19

13. It’s Time to Test... Suggested Readings:
Antonini, C.J., et al. Scanning EMS of Scalers. J. Periodontol., 48(1), Jan.1977.
Testing the Gracey Curette – A New Time Zone
Carranza, F.A., ed. Glickman’s Clinical Periodontology. 6th ed. Philadelphia:
Test Stick Position: W.B. Sanders Co., 1984.
The position for the test stick and the terminal shank of the Gracey instrument DeNucci, D.J., and Mader, C.L. Scanning Electron Microscopic Evaluation of
is twelve o’clock. Several Resharpening Techniques. J. Periodontol., 54(10), Oct. 1983.
Instrument Position for Right-handers: Fedi, P.F. and Vernino, A.R. The Periodontic Syllabus. 3rd ed. Baltimore:
In your dominant hand, hold the instrument with a mod- Williams and Wilkins, 1995.
ified pen grasp. For odd-numbered Gracey ends the toe
will be pointed toward you. Bring the instrument around Grant, D.A., Stern, I.B., and Listgarten, M.A. Periodontics. St. Louis:
behind the test stick with the cutting edge to be sharp- C.V.Mosby, 1988.
ened against the left side of the test stick and fulcrum on Marquam, B.J. Strategies to Improve Sharpening. Dent. Hyg., July/Aug. 1988.
the right side. For even-numbered Gracey ends the toe Murray, G.H., Lubow, R.M., et al. The Effects of Two Sharpening Methods on the
will be pointed away from you and you will bring the Strength of a Periodontal Scaling Instrument. J. Periodontol., 55(7), July 1984.
instrument in front of the test stick. Hold both the ter-
minal shank and the test stick at the twelve o’clock posi- Nield, G., and Snyder, N. An Edge On Success Videotape Series. Univ. Of
tion. Be sure not to rest your ring finger on the top of the test stick. Place Texas, San Antonio, 1986.
your ring finger against the side of the test stick opposite the cutting edge Paquette, D.E., and Levin, M.P. The Sharpening of Scaling Instruments: Part
to act as a fulcrum while testing. Testing must be done at exactly the same I–An Examination of Principles. J. Periodontol., 48(3), March 1977.
angle that the blade is used for scaling.
Paquette, D.E., and Levin, M.P. The Sharpening of Scaling Instruments: Part
Instrument Position for Left-handers: II–A Preferred Technique. J. Periodontol., 48(3), March 1977.
In your dominant hand, hold the instrument with a mod- Pattison, A.M., and Pattison, G.L. Periodontal Instrumentation. 2nd ed.
ified pen grasp. For even-numbered Gracey ends the toe Norwalk: Ct., Appleton and Lange, 1992.
will be pointed toward you. Bring the instrument around
behind the test stick with the cutting edge to be sharp- Perry, D.A., Beemsterboer, P., and Carranza, F.A. Techniques and Theory of
ened against the right side of the test stick and fulcrum Periodontal Instrumentation. Philadelphia: W.B. Sanders Co., 1980.
on the left side. For odd-numbered Gracey ends the toe Sasse, J. Cutting Edges of Curets: Effects of Repeated Sterilization. Dent.
will be pointed away from you and you will bring the Hyg., 61, Jan. 1987.
instrument in front of the test stick. Hold both the ter-
Tal, H., et al. SEM Evaluation of Wear of Curets During Standardized Root
minal shank and the test stick at the twelve o’clock posi-
Planning. J. Periodontol., 56(9), Sept. 1987.
tion. Be sure not to rest your ring finger on the top of the test stick. Place
your ring finger against the side of the test stick opposite the cutting edge Wilkins, E.M. Clinical Practice of the Dental Hygienist. 7th ed. Philadelphia:
to act as a fulcrum while testing. Testing must be done at exactly the same Lea and Febiger, 1994.
angle that the blade is used for scaling. Woodall, I. Comprehensive Dental Hygiene Care. 4th ed. St. Louis: C.V.
Testing the Cutting Edge: Mosby, 1993.
Press the cutting edge into the test stick and release. Test the entire length Zimmer, S. Instrument Sharpening–Sickle Scalers and Curettes. Dent. Hyg.,
of the blade. A sharp edge will bite into or grab the test stick. When the 52, Jan. 1978.
edge is removed it produces a metallic sound. If the cutting edge slides
over the side of the test stick it may indicate the blade is still dull, the ter-
minal shank is not positioned correctly, or the stone has not been posi-
tioned properly while grinding.
20 21

14. Glossary of Terms: Chart of Angles
90° 135° 110°
Burnishing 90° 45° 70°
To polish or smooth over a deposit instead of removing it. This occurs during
scaling with the use of dull instruments.
Dominant/Nondominant Hand
For right-handers, your dominant hand is your right hand and nondominant Not Enough Angulation Too Much Angulation Correct Angulation
is your left hand. When the internal angle When the internal angle When the stone is cor-
is greater than 80°, the is less than 70°, the rectly placed against the
For left-handers, your dominant hand is your left hand and nondominant is blade becomes bulky blade becomes weak blade, the internal angle
your right hand. and is difficult to adapt and also dulls quickly. of approximately 70° is
to the tooth. maintained.
Fulcrum
The finger rest used to stabilize the dominant hand during instrumentation or
testing the blade for sharpness.
Clock Face Positions
Modified Pen Grasp Sickle Scalers & Universal Curettes
The instrument is held with the thumb and index finger placed on opposite Terminal shank at 12:00
sides of the handle. The middle finger is placed on the shank to guide the Top of stone at 4 Top of stone tilted at 4
movement of the blade and the ring finger serves as the fulcrum. minutes after 12:00 for minutes before 12:00 for
right-handers left-handers
Secure Palm Grasp
The instrument is held securely in the palm of the hand with the index finger
or thumb near the top of the instrument to stabilize the instrument when
sharpening.
Sludge
The accumulation of metal filings that becomes suspended in the oil on the
surface of the sharpening stone.
Terminal Shank
The section that extends between the blade and the first angle (or bend) in
the shank. Gracey Curettes
Terminal shank toward 11:00 Terminal shank toward 1:00
Wire Edge Top of stone at 4 Top of stone at 4
A particle of metal that adheres to the cutting edge after grinding. minutes after 12:00 for minutes before 12:00 for
right-handers left-handers
22 23

15. Right-handers
A Timely Approach to Instrument Sharpening
Sickle Scalers & Gracey Curettes
Universal Curettes
Take Time for Tips & Toes
Sickle Scalers & Universal Curettes Gracey Curettes
1 Position instrument vertically with blade 1 Position instrument vertically with blade
to be sharpened at 6:00. to be sharpened at 6:00.
2 Stabilize entire length of instrument with 2 Check the blade identification number:
a firm grasp. Aim the toe of all ODD-numbered
3 Balance upper shank with index finger or Graceys toward you.
thumb. Direct the toe of all EVEN-numbered
4 Point tip or toe of blade toward you to Graceys away from you.
sharpen right cutting edge and away from 3 Stabilize entire length of instrument with
you to sharpen opposite cutting edge. a firm grasp.
5 Hold terminal shank at 12:00. 4 Counterbalance top shank with index fin-
6 Place side of stone against right lateral ger or thumb.
surface. 5 Tilt terminal shank toward 11:00.
7 Tilt top of stone toward, not beyond, 6 Hold stone against right lateral surface
1:00. and tilt toward 1:00.
8 Move stone up and down in three distinct 7 Move stone up and down in three distinct
sections of the blade: heel third, middle sections of the blade: heel third, middle
third, anterior third. third, and anterior third.
9 For curettes, rotate the instrument blade 8 Repeat steps #9, 10, and 11 to “round”
toward 3:00. the toe.
Hu-Friedy Mfg. Co., Inc.
10 Aim the stone at 2:00.
3232 N. Rockwell Street
Chicago, IL 60618 USA 11 Use continuous and overlapping up-and-
down motions to “round” the toe.
SHM/1.5M/3-09
SDVD

16. POST-TEST
Instructions for Earning Continuing Education Credit
Please submit completed post-test*and registration form along with a $20 (US$)
processing fee to:
Continuing Education Department
School of Dentistry
University of Missouri-Kansas City
650 E. 25th Street
Kansas City, Missouri 64108
Please make checks payable to the University of Missouri-Kansas City. Please allow
5-6 weeks for delivery of results. Participants must score at least 70% to earn two
hours of Continuing Education Credit.
*Photocopies of the post test cannot be accepted.
Individuals must notify the State or Provincial Dental Board of credit received. It
is the responsibility of each individual to check the state’s licensure requirements
related to continuing education credit through self-study or correspondence
courses and the accepted number of hours permitted for such courses.
Registration Form
(Must accompany completed post-test and $20 [US$] processing fee)
Important: To ensure that you receive credit, the following information must
be typed or printed legibly:
NAME
ADDRESS
CITY STATE/PROV. ZIP CODE/POSTAL CODE
SOCIAL SECURITY#
OFFICE TELEPHONE NUMBER
SIGNATURE

17. Post-Test 5. This sharpening method recommends grasping the sharpening stone
a. In the non-dominant hand
b. In the dominant hand with the index finger braced against the top
c. With fingers and thumbs firmly placed on all four surfaces
Circle the letter beside the one response that best completes d. With the thumb on the side of the stone facing you and
the statement according to the information contained in this the fingers on the opposite side away from you
manual. e. None of the above
1. A “dull “ cutting edge 6. When sharpening a Sickle Scaler according to the hands of the clock
1. May contribute to patient discomfort a. The terminal shank is aimed straight up at 12:00
2. May contribute to operator fatigue b. The stone initially is placed against the lateral surface at 12:00
3. May contribute to effective treatment c. Right-handers reposition top of stone toward 1:00; Left-handers
a. All statements are true reposition top of stone toward 11:00
b. Only 1 and 2 are true d. The stone grinds the blade in three sections, the heel third,
c. Only 2 and 3 are true middle third and tip third
d. Only 1 and 3 are true e. All of the above
e. Only 3 is true
7. Universal Curettes are
2. Which stone grit is recommended for removing “wire edges” after a. Unable to be sharpened due to the acute angles in the shank
sharpening? b. Positioned with the terminal shank at 12:00 as with Sickle Scalers
a. Fine c. Positioned with the terminal shank at either 11:00 (for left-handers)
b. Medium or 1:00 (for-right handers)
c. Coarse d. Placed at a 4:00 position to contour the heel third
e. None of the above
3. With the simplified sharpening strategy, the most frequently
8. To properly position Gracey Curettes
employed clock positions are a. The terminal shank will be at 12:00
a. 3:00; 4:00; and 5:00 b. Read the labels on the handle to determine the bends and
b. 11:00; 12:00; and 1:00 angles in the shank
c. 6:00; 7:00; and 8:00 c. The toe of the blade will always be aimed at 11:00
d. 4:00; 8:00; and 10:00 d. All of the above
e. None of the above e. None of the above
4. Which part of the instrument must be precisely positioned in 9. To test the sharpness of a Gracey Curette with a Plastic Test Stick
relationship to the clock during sharpening of the lateral surface a. Tilt the terminal shank toward 1:00
of the blade? b. Tilt the terminal shank toward 3:00 or 9:00
a. Handle c. Tilt the terminal shank at 7:30–9:00
b. Blade d. Place the terminal shankat 12:00 parallel with the side of the test stick
c. Shank e. None of the above
d. Terminal Shank
10. To round the toe of a Gracey or Universal Curette
e. None of the above
a. The same clock positions are used for sharpening the lateral surface
b. The toe of the instrument is pointed toward you
c. The stone is positioned toward 2:00 for right-handers and
10:00 for left-handers
d. The toe does not need to be sharpened because it is never used
e. None of the above