instrument care and sharpening

instrument sharpening 

-used to preserve the original shape of the blade and restore the cutting 

-each instrument is designed for a specific purpose

-essential part of instrumentation 

inaccurate techniques with sharpening

will lead to distort the shape and render it useless

benefits of sharpening

-complete procedures efficiently and with no trauma

-increased tactile sensitivity

-more control

-less strokes

-lower chance of burnishing calc and disfiguring the tooth

-causes less fatigue for clinician

consequences of dull instruments

-burnish or inadequately remove calc deposits

-wasted time, effort, and energy

-loss of control can lead to tissue lacerations 

-loss of patients confidence in you

-increased likelihood of developing muscle fatigue and skeletal disorders

dynamics of sharpening

-accomplished by filing the surfaces that form the cutting edge

-cutting edge is the fine line where the face and lateral surfaces meet

instrument is dull or nicked

-pressed against hard surface

-goes over rough surface

-45 scaling strokes or even as little as 15

• always out for every patient

• class II patients every 2-3 teeth

• class III patient every 1-2 teeth

-restore the cutting edge to a fine line

stone or card surface

-acts as an abrasive to reshape a dull edge 

-crystals are the abrasive particles to accomplish the grinding

-smaller particle/fine grit which reduces the instrument slowly and produces a finer cutting edge

sharpening devices

-stones

-power driven/mechanical devices

stone types

natural or artificial materials

types of natural stones 

-Arkansas

-India

these need a lubricant bc they dry out fast

types of artificial stones

-ruby

-carborundum

-diamond

-diamond coated stainless steal (what we have)

basic principles of sharpening

-sterilization

-preparation of stone

-lubrication of stone

sterilization with sharpening

card and test stick go in autoclave and bag after each use

preparation of stone 

dry the stone if wet to better maintain a sterile environment

lubrication of stone

-use water or oil

-quarried stone= prevent drying out 

-metal shavings can become suspended= nicking 

sharpening overview

-objectives

-when to sharpen

-angulation

-maintain control

-care of stone

objectives of sharpening

-produce sharp cutting edge

-reserve original shape 

-for a curette move in a straight line around toe

-for a scaler move inward as tip is approached

when to sharpen

at the first sign of dullness

angulation when sharpening

-establish proper angle and maintain it

-using firm palm grasp, stabilize with thumb, elbow tucked in

-secure elbow rest in front of you

-slight to moderate pressure

-short controlled strokes

maintaining control when sharpening 

-make sure entire cutting edge is reduced evenly 

-do not create bevel or damage to the cutting edge

taking care of stone

-prevent grooving

-vary areas used to sharpen throughout stone

cleaning stone

-ultrasonic or soap with water

-stone or card with test stick goes in sterilized seal pouch, done by student and put in transport box

tests for sharpness

-visual or glare

-plastic stick 

visual or glare sharpening test

-make sure you have good lighting and magnification

-if its sharp the cutting edge does not reflect light

-if its dull the cutting edge can reflect light

plastic stick test

-plastic or acrylic

-1/4 inch rod

-3 inches in length

-fulcrum on stick

-start at heal with 90 degree angle

-press lightly but firm into stick

-grab, bite stick and do upward motion not in scaling stroke

-make sure to the the entire length of cutting edge

confirming sharpness with plastic stick

-sharp= hear ping sound

-dull= slide along stick

evaluation of sharpening technique

-instrument is secure and not moving

-stone moves in single plane, up and down when activated with thumb in front and 4 fingers back

-instrument and stone positioned at correct angle

after sharping

-inspect and clean off wired edges that are produced with grinding against stone with a dry gauze

instrument wear

-happens from use and sharpening

-after it has sufficient reduction it should be discarded since it no longer will adapt to tooth and since its thin we want to avoid tip breakage

sharpening scalers 

-cutting edges on both sides of the face

-tip is pointed

-2 step sharpening procedure

universal curette sharpening

-cutting edges on both sides of the face

-toe is rounded

-3 step sharpening procedure

area specific curette sharpening

-cutting edge on one side of the face

-toes is rounded

-2 step sharpening procedure

stabilization and position of instrument during sharpening

-in nondominant hand with palm grasp

-elbow on steady surface with good lighting

-positioned low enough for good visibility

-odd end towards you, even end away from you

-cutting edge parallel to the floor

-card perpendicular to the floor

-card and instrument make 90 degree angle 

-open card to a 100-110 degree angle 

-maintain that angle throughout procedure

-start at heel, then middle, and end at toe/tip

-short ½ inch strokes, moderate pressure

-end on downward stroke and wipe with gauze

positions for universal curette and scaler

-face parallel to floor

-terminal shank at 12

-card at 1 or 11

positions for area specific curette

-face parallel to the floor

-terminal shank at 11 or 1

-card at 11 or 1

rounding the toe when sharpening 

-move instrument to 3/9 and place card at 90 degree angle or parallel to the floor under instrument

-open or move card to 2 or 10

-move card around toe of curette from one side to the other using moderate pressure ensuring the original design