instrument sharpening Flashcards
why should Instruments be kept sharp
to be as true to their original design as
possible
what technique is the most effective when using sharp instruments? why?
scaling because it…
reduces fatigue - less lateral pressure!
improves deposit removal
saves time
improves tactile sensitivity
minimizes patient discomfort
does a dull cutting edge reflect light? what about sharp cutting edge?
dull = reflect light
sharp = does not reflect light
when the blade is dull…
one loses the ability to “feel” the sharp
edge “grabbing” onto a surface
burnishing occurs when
blade slides over the deposit rather than removing it
(burnishing) Deposit that has had the outermost layer removed…
surface is smooth
why is burnished calculus is difficult to remove/detect
the blade can slip over the smoothed surface
types of sharpening
- stones
- diamond cards
- disc
- saddle
- automated: sidekick
types of stones
- arkansas stone
- ceramic stone
- india stone
arkansas stone
- Natural stone
with a fine grit - Light
recontouring and
maintenance - Oil lubrication
ceramic stone
- Hard synthetic stone
- Fine, medium or course
grit - Routine sharpening of
dental instruments - Water lubrication or dry
india stone
- Synthetic stone
composed of
aluminum oxide
crystals - Fine, medium or
course grit - Reconditioning/
recontouring,
maintenance - Oil or water
lubrication - Widest variety
sidekick angulation
channels:
1. gracey
2. sickles and universals
Position the instrument in
the specific channel
the terminal shank
resting on the incline of
the channel
Position the back of the
instrument along the
backstop of the guide
plate
for best results, how should instruments be sharpened?
with FINE stone after each use
for best results, new instruments should be sharpened with?
fine side of the stone
when sharpening, how should the face of the instrument always be positioned?
always parallel to the floor
what materials are needed for sharpening?
- full PPE
- sharpening stone
- test stick
- light
- gauze
- rubric
what is not enough angulation when sharpening?
when the internal angle is greater than 80 degrees, the blade becomes bulky and is difficult to adapt to the tooth
what is too much angulation?
when the internal angle is less than 70 degrees, the blade becomes weak and also dulls quickly
what is correct angulation
when the stone is correctly placed against the blade, the internal angle of approx. 70 degrees is maintained
sharpening sickle scalers instrument position
Hold the instrument vertically in your non-dominant hand with a secure
palm grasp
Face of blade parallel to floor with the tip pointed toward you
Elbow on the table or tucked in at waist
sharpening sickle scalers stone position
Hold stone with dominant hand, thumb on top, middle and fulcrum finger
on bottom.
Place the FINE (WHITE) side of the stone against the right lateral surface
of the blade
First place the stone at twelve o’clock (90 degrees) and then tilt the top of
the stone to slightly less than one o’clock (110 degrees)
sharpening Sickle scalers stone movement
Fluid up-and-down motion
Apply more pressure on the DOWN motion
Start at the heel third of the blade
Continue to the middle third
Finish at the the tip third
Always finish with a down stroke!
sharpening Sickle scalers opposite cutting edge
Tip pointed towards you
Keep a secure palm grasp
Place the stone toward eleven o’clock
Repeat the grinding process, maintaining the clock position.
Always finish with a down stroke!
sharpening Gracey curettes
ONE cutting edge, be sure to sharpen the correct side!
Face is offset at 70°
Hold the terminal shank at 110° so that the face is parallel to the
floor
Rounded Toe
As you move the stone, follow the rounded toe of the cutting edge
testing edge sharpness
Slide the cutting edge against the
test stick and release.
Test the entire length of the
blade.
A sharp edge will bite into or
grab the test stick, don’t push
hard!
When the edge is removed, it
produces a metal sound
