This document discusses different methods for sharpening dental instruments, including stationary sharpening stones, mechanical sharpeners, and handpiece stones. It describes the types of stones used like Arkansas, silicon carbide, aluminum oxide, and diamond. Key details are provided on grit sizes, stone shapes, and the basic principles of maintaining proper bevel angles and light pressure while sharpening. Mechanical sharpeners and techniques for specific instruments like chisels and knives are also outlined. The document concludes with sterilization requirements after sharpening instruments.

1. Sharpening Hand Instrument
Aquino, Karl Yveth A.
DDM2B

2. “Stone”
• The most frequently used sharpening
equipment consist of block or stick of abrasive
material.
• Supported on a firm surface and the
instrument is oriented and held by hand while
being stroked against the stone surface.

3. Types of Sharpening Equipment
1. Stationary Sharpening Stone
2. Mechanical Sharpeners
3. Handpiece Stone

4. 1.Stationary Sharpening stone
• are often called oilstone.
• Available in coarse, medium, or fine
grits.
• Can obtained in a variety of shapes
including Flat, grooved, Cylindrical, and
tapered.

5. Grit – Coarse initial reshaping of
Medium badly damage
instrument
Fine Final Sharpening

6. Shapes of Stone
• Flat stone
– Preferred for sharpening all instrument which have
straight cutting edge .
• Cylindrical stone
– Used for sharpening instrument with concave edges
• Grooved
– curved edges.
• Tapered stone
– Permit using a portion of a stone with a curvature
matching that of the instrument.

7. 1.Stationary Sharpening stone
4 Types of material for sharpening
stone :
Arkansas Stone
Silicon Carbide
Aluminum Oxide
Diamond

8. Arkansas stone
• Naturally occurring mineral containing micro
crystalline
quartz.
• Used in fine sharpening stones.
• Semi transparent, white or grey in color.
• Hard enough to sharpen steel but not carbide
instruments.
• Should be lubricated with machine oil which helps in
fineness of sharpening and prevents clogging avoids
creation of heat.

9. Silicon carbide
• Widely used as an industrial abrasive.
• Used for grinding wheels, sand papers and
sharpening stones.
• Hard enough to cut steel but not to sharpen
carbide instruments.
• Available in medium and coarse grits.
• Black or greenish black in color and require
lubrication with oil.

10. Aluminum Oxide
• Used to
manufacture
sharpening stones
• Available in
coarse, medium
and fine grits

11. Diamond
• Hardest available abrasive.
• Effective for cutting and shaping hard
materials.
• Used in sharpening carbide and steel
instruments.
• Diamond hones are small blocks of metal with
fine diamond particles impregnated in the
surface

12. 2. Mechanical Sharpeners
• Honing machine:-
- This instrument moves a hone
in a reciprocating motion at a
slow speed, while the instrument
is held at the appropriate
angulation and supported by a
rest.
- This type of sharpener is very
versatile, and can fill almost all
instrument sharpening needs.

13. 3.Handpiece Stone
- Mounted silicon carbide and aluminum oxide
stones for use with straight and angle hand
piece are available in various sizes and shapes.
- Used to sharpen instruments with curved
blades.

14. Basic Principle of Sharpening
1. Sharpens instrument only after they have
been cleaned and sterilized.
2. Establish the proper bevel angle (usually
45⁰)and the desired angle of the cutting edge
to the blade before placing the instrument
against the stone and maintain this angles
while sharpening.
3. Use a light stroke or pressure against the
stone to minimize frictional heat
4. Use a rest or guide whenever possible

15. 5. Remove as little metal from the blade as
possible.
6. Lightly hone the unbeveled side of the
sharpening to remove a fine bur that may be
created.
7. After sharpening, resterilize the instrument along
with other items on the instrument tray setup.
8. Keep the sharpening stone clean and free of
metal cutting.

16. Mechanical Techniques
• When chisels, hoes, angle formers, or gingival
margin trimmers are sharpened on a
reciprocating honing sharpener, the blade is
placed against the steady rest, and the proper
angle of cutting edge of the blade is
established before starting the motor.

17. Stationary Stone Techniques
Should be at least:
– Wide : 2 inches
– Long : 5 inches
• It also should be of medium grit for hand
cutting instrument, before the stone is
used, a thin film of light oil should be
placed on working surface.

18. FUNDAMENTAL RULES that apply to
using stationary stone
1. Lay the stone on a flat surface and do not tilt
the stone while sharpening.
2. Grasp the instrument firmly.
3. To ensure stability during the sharpening
strokes, use the ring and little fingers at rest
and guide along a flat surface or along the
stone.
4. Use a light stroke
5. Use different areas of the stone’s surface
while sharpening.

19.  Burr or burr-edge
⁻ Single bevel instrument are sharpened, a
thin, rough ridge distorted metal
⁻ This burr is eliminated by a light stroke of
the unbeveled side of the blade over the
stone

20.  Amalgam or Gold knife
⁻ Has a very thin blade tapering to the
sharpened edge.
⁻ There is a narrow edge bevel on both
side of the blade

21. Spoon excavator and discoid
⁻ The most instrument to
sharpened.
⁻ The sharpening can be achieved
by using a grooved stone,
mounted discs or stone for use
with a straight handpiece

22. Sterilization and storage of hand
cutting instrument
• It can be accomplish by autoclaving, dry heat
procedure, ethylene oxide equipment and
chemical vapor sterilize.
• Boiling and chemical solution will nit sterilize
instrument and should be considered as
disinfection procedure.
• Storage of any hand instrument should be in a
sterile wrapped tray setup, or in an individual
sterile wrapping

23. Powered Cutting Equipment
Development of rotary equipment
Date Instrument Speed
(rpm)
1728 Hand-Rotated Instrument 300
1871 Foot Engine 700
1874 Electric Engine 1000
1914 Dental Unit 5000
1942 Diamond Cutting Instrument 5000
1946 Old Unit converted to increase
speed
10000
1947 Tungsten Carbide Burs 12000

24. 1953 Ball Bearing Handpiece 25000
1955 Water Turbine angle
Handpiece
50000
1955 Belt-Driven angle Handpiece 150000
1957 Air Turbine angle Handpiece 250000
1961 Air Straight Handpiece 25000
1962 Experimental Air Bearing
Handpiece
(800000)
1994 Contemporary air turbine
Handpiece
300000