theory II ch 36
Card Set Information
theory II ch 36
ch 36 theory II
why does a sharp edge not reflect light?
because it is a fine line
the dull cutting edge is a ______, _____ surface that reflects light
the plastic testing stick procedure starts at the heel (shank end) of the cutting edge to the plastic stick at ___degrees , then closed to the correct angle for scaling ____degrees
plastic testing stick with an instrument should be ____ but ______
lightly but firmly
(plastic testing stick) roll the cutting edge _____ from the shank end to the toe by turning or rolling the instrument handle in the fingers to test the _____ length of the _____
t/f during the plastic stick test, the blade will be uniform dull/sharp throughout the entire length of the blade
false! portions of the blade will exhibit varying degrees of sharpness or dullness
if only part of the instrument blade is dull, only sharpen that specific area
FALSE! the entire length is always sharpened to maintain original form
awareness of the areas of the instrument that are dull helps with guidance to minimize _________
when starting to sharpen, look at the ____ of the instrument to ensure it is secure and not moving. make sure it remains in a _____ plane of movement back and forth as it is activated
how can a solid consistent bevel form?
when the instrument and stone are positioned at the correct angle
the movement is in a single plane
an instrument that is irregular beveled is:
-one that breaks the fine line of the blade edge
-varying facets indicate the improper stone placement/movement
____ stone sharpens the cutting edge without nicks in the blade; they can be created from particles of metal suspended in a _______
ceramic stones may be used ____ or with _____
why do some quarried stones need lubrication?
-to prevent drying out
-prevent scratching of the stone
-suspends the metallic particles removed during sharpening to prevent clogging of the pores of the stone (glazing)
for lubricated stone use...when can you use it to sharpen instruments?
instruments are autoclaved before sharpening, and then they are both sterilized again after the NONSTERILE lubricant is used
what are the twofold objectives for sharpening?
produce a sharp cutting edge
preserve original shape of instrument
the contour of a curet toe is a ____, continuous curvature with no _____ or flat _____
t/f sharpening should be done when?
at the first sign of dullness during an appt and when the blade is not functional!
t/f recontouring wastes the instrumetn
if you restore a contour to a grossly dulled instrument, the blade will not be _________ and _______
what should be done before starting to sharpen with the angulation?
analyze the cutting edge and establish the proper angle between the stone and blade
a firm grasp, secure hand rest, moderate pressure, short strokes should be used when doing what?
get your mind out of the gutter....
when maintaining the angle for sharpening
what do you look for when finishing the instrument sharpening?
inspect the edges for a clean consistent bevel with no particles or "wire edges" remaining
what is a wire edge and how is it produced?
during sharpening when some of the metal particles removed during grinding stay attached to the edge of the instrument and create the wire edge
if a wire edge stays on the instrument, ____ ______ may be removed when the instrument is applied to the tooth surface during tx
how is a wire edge minimized?
by sharpening into, toward, or against the cutting edge
black marks on a stone when sharpening indicates what?
correct sharpening of the stone! yay!
what can happen if an instrument is not properly sharpened?
how do you remove a wire edge from an instrument?
with a dry gauze or alcohol wipe to remove particles
what wears down when curets are used? what do they lead to?
cutting edges lead to a narrower face and shorter length over time
t/f sharpening contributes to the size reduction
when should instruments be discarded? 2
when the blades no longer access or adapt to the tooth surface
thinner blades are more susceptible to breakage with lateral pressure
t/f instruments that have become excessively narrow are reserved for pt's with minimal deposit and require biofilm debridement
an area specific curet is sharpened on the _____ cutting edge and the rounded ____
t/f a scaler is sharpened on the two sides, and the toe is brought to a point
false! the tip is brought to a point
why is sharpening frequently recommended?
to prevent the need for excessive recontouring of the blade
t/f most sickles are universal instruments
t/f cutting edges of both sides of the face and toe are sharpened on a universal curet
____ ____ sharpening procedure is used for universal curets
what kind of grasp is used with curets and sickles for sharpening?
modified pen grasp
a ____-____ sharpening procedure is used with area specific curets
the flat stone is _____ and the instrument is ______ when sharpening
at the dull cutting edge, the internal angle of the blade is ___-___ degrees
at which angle should the stone be placed from the stone to the single plane of the instrument?
the strokes for sharpening should be ___ and ____
short and overlapping