DH119A Instrument Sharpening

what are the goals of sharpening

preservation of the instrument blade, maintenance of the original contour of the instrument and to attain an evenly sharp cutting edge

advantages of a sharp instrument

less lateral pressure is required to remove hard deposits, greater patient comfort, minimum fatigue, greater control, increased tactile sensitivity and more efficient use of time

what equipment is used for sharpening?

sharpening stone, method/device, adequate bright light source, magnification, plastic stick test, sterile work area, PPE

criteria of a goof sharpening stone

must be harder than surface to be sharpened, must be long lasting, mad of abrasive particles and must be sterilizable

how are stones categorized?

according to particle size, intended use and shape

which type of grit is described?
natural or synthetic, smaller particle size-less abrasive, best for final sharpening to finer edge

super fine/fine/medium fine grit

which type of grit is described?
synthetic, larger particle size=more abrasive, best for very dull instruments or recontouring

course grit

shapes of sharpening stones

flat, grooved, wedged, conical, other

type of natural stone

arkansas stone

types of synthetic stone

ceramic/moon stone, india stone, carborundum, stainless steel/diamond coated, tanged file

natural, fine grained, 99.4% silica, also called novaculite, MOHS hardness=7.5, flat conical or wedges, gray black or white

arkansas stone

applications of the arkansas stone

sharpening moderately dull instrument, routine sharpening, to attain a fine edge, polish the edge of the instrument

care/use of arkansas stone

mineral oil needed for lubrication, may clean un ultrasonic/scrub w/soap and water to remove oil/sludge that builds up on stone, may use fine grit sandpaper to roughen stone surface, sterilizable-steam, chemical vapor or dry heat

synthetic, made from aluminum oxide-kiln fired, MOHS hardness=9.22, long lasting

ceramic/moon stone

grit for a ceramic stone

single grit (fine, medium or coarse, finer=smaller), or dual grit

shapes/colors of ceramic stones

rectangular or cylindrical, white, blue, dark gray or red brown

applications of a ceramic stone

routine sharpening, to attain fine edge, reshaping of excessively worn instruments

care/use of ceramic stone

no oil needed, use w/ or w/out water, clean in ultrasonic or scrub w/ water to remove metal particles, sterilizable; steam, chemical vapor or dry heat

synthetic, fine, medium, coarse grit, made of alumimum oxide, MOHS hardness is 9.0, rectangular, light red or brown

india stone

applications of india stone

routine sharpening, recontour or sharpen excessively dull instruments

care/use of india stone

mineral oil/water as lubricant, may clean in ultrasonic or scrub w/ soap/water to remove oil/metal particles, may use fine grit sandpaper to roughen stone surface, sterilizable-steam, chemical vapor or dry heat

synthetic, flat or conical shape, coarse grit, preliminary shaping or sharpening of excessively dull instruments, use w/ water

carborundum stones

characteristics of diamond stone

stainless steel w/ micronized diamond surface coating, various shapes- card type and cone shaped, extra fine/fine/medium grit, durable, shatter resistant

applications of diamond stones

fine sharpening, regular maintenance, recontouring

care/use of diamond stones

clean via ultrasonic cleaner and steam sterilization, use dry, no oil lubrication required

not a stone by definition, but a special sharpening device, made of carbon steel, used for sharpening of files, sterilizable, but may become "tarnished" over time

tanged file

when to sharpen instruments?

whenever instruments become dull depending on patient load/schedule, frequency of use, type/difficulty of procedure performed, best after sterilization

what is a dulled edge characterized by?

a rounded cutting edge, does not allow instrument to engage the surface

how to detect a dull edge

tactile; calculus is not removed/burnished, increased lateral pressure is required for the instrument to be effective, visual; reflection of light, bite/grip test; plastic stick following sharpening, instrument grips or stops at working angle (60-90 degre

explain the process of evaluating for sharpness visually

inspect the cutting edge of the instrument by holding the instrument under a bright light, rotate instrument slightly to reflect light onto lateral surface, a dull cutting edge will reflect light, a sharp cutting edge will not reflect or it will have a ma

explain the process of evaluating for sharpness using the plastic stick test

hold the test stick in non-dominant hand between thumb and index finger w/ 3/4 of the stick above the finger, w/ dominant hand, hold instrument in modified pen grasp and place cutting edge against stick, tip instrument shank toward test stick, applying sl

two cutting edges

universal curette/sickle scaler

one cutting edge

area specific curette

what adaptation maintains the ideal cutting edge

Adaptation of the stone against the lateral surface at 1100 to the face, will best maintain the integrity of the instrument shape (with 700 internal angle)

face is sharpened using a mandrel mounted stone, difficult to maintain consistency due to variations in speed and stabilization of the stone/instrument, instrument is worn away quickly but remains the same width

rotary method

consistent, reproducible sharpening results, can be large and bulky, not easily transportable, care should be taken when using-can wear more quickly, more expensive initial cost

motorized honing machines

explain the manual technique of the stationary stone/moving instrument

lateral surface of instrument against the stone, face oriented at 110 degrees, difficult to maintain face to blade angulation while moving instrument

flat stone used w/ metal guide, instrument lateral surface is adapted to stone by orienting the terminal shank against the guide plate, instrument is moved across the stone in back and forth motion

PDT/gleason guide sharpener

instrument is adapted to stationary stone, handle is oriented to protractor dial, dial moves for exact 110 degree angulation, various dial positions account for various shank curvatures, instrument is moved w/ a pull stroke against the stone, maintaining

premier wheel

instrument is oriented against a guide, stone is adapted to the lateral surface of the instrument at a predetermined angle, stone is moved in a up and down motion against the lateral surface, stone must be moves in consistent dimensional plane to create a

sharpen-rite guide

battery operated device, ceramic stone moves as instrument is adapted using an angled guideplate, no lubrication needed for the stone, recommended routine sharpening, not for recontouring

sidekick sharpener

advantages of sharpening services

consistently sharpened edge and blade, saves time in clinical preparation

disadvantages of sharpening services

expense, instruments not readily available for use

sharpening considerations

must have knowledge of original shape/contour, consider degree of sharpening required, must have a stable, firm grasp of instrument and stone, must be consistent w/ technique/device, competence takes time