instrumentation module 8

unpaired working-ends

instrument with 2 dissimilar working-ends

paired working-ends

instrument with working-ends that are mirror images of each other

design name

school or person who designed instrument

design number

identifies the working-ends

number along handle

each working-end is identified by the number closest to its end

number across handle

-first number identifies working-end on top

-second number is working-end on lower end of the handle

recommended characteristics of the right handle

-large diameter

-lightweight handle

-bumpy texturing

balance of periodontal instrument

working-ends are aligned with the long axis of the tooth; centered with midline of the handle

shank bends

bent in one or more places to facilitate placement of the working-end against the tooth surface

simple shank design

when holding the working-end facing you the toe with appear to be straight

complex shank design

-when you face the toe towards you it appears to have side-to-side bends

simple shanks are used for

anterior teeth

complex shanks are used for

posterior teeth

simple shank: anterior teeth

-wedge shaped teeth

-adequate to reach along the crown and onto the root

complex shank: anterior teeth

-large, bulky crowns that are larger in diameter than the roots

-parallel to terminal shank that let’s you get around

functional shank

portion of shank that allows the working-end to be adapted to the tooth surface

lower shank

portion of functional shank that is nearest to the working-end; also called the “terminal” shank

functional shank location

begins below the working end, and extends to the last bend in the shank nearest the handle

lower shank location

portion of functional shank nearest to the working-end

simple shank with short functional shank length

supragingival use on anterior teeth

simple shank with long functional shank length

subgingival use on anterior teeth

complex shank with short functional shank length

supragingival use on posterior teeth

complex shank with long functional shank length

subgingival use on posterior teeth

use of extended lower shank

to reach the middle and apical-third of the root surface

parts of working-end

-face

-back

-lateral surfaces

-cutting edge

-toe or tip

face

top surface of working-end

back

bottom surface of the working-end

lateral surface

surfaces on the sides of the face

cutting edge

sharp edge formed where face and lateral surfaces meet; most working-ends have 2 cutting edges

toe

from bird’s eye view looking down on face where the cutting edges meet to form a rounded shape

tip

from bird-eye view looking down on face where the cutting edge meets to form a pointed shape

significance of cross section

determines whether the instrument can be used subgingivally or supragingivally

subginvial

beneath the gingival margin

supragingival

above the gingival margin

shape of toe cross section

semi-circular

shape of tip cross section

triangular

scalers

-instruments with triangular cross section

-limited to supragingival use

curets

-instruments that are semi-circular cross section

-may be used supragingivally and subgingivally

assessment intruments

-periodontal probe

-explorer

calculus removal instruments

-sickle scalers

-curets

-periodontal files

periodontal probe

slender instrument used to evaluate the health of periodontal tissues; blunt and rod shaped working ends

calibrated probe

marked off in millimeter increments for measurement

explorer

used to locate calculus deposits and tooth irregularities; circular in cross section

-designed with thin flexible shank to provide excellent tactile sensitivity

-fine wirelike working end that terminates in a sharp point

scaler

-used to remove supragingival calculus deposits

-triangle cross section

-pointed tip, pointed back

-strong instrument

-two cutting edges used

curet

-used to remove calculus deposits

-semi circular cross section

-rounded toe, rounded back

types of curets

-universal

-area specific

universal curet

-2 cutting edge parallel to one another

-face of blade is at 90 degree angle to shank

area-specific shank

-face is tilted in relationship to lower shank to 60-70 degree

-lower angle side has a cutting edge

periodontal file

-used to crush large calculus deposits

-each working-end has several cutting edges