Hand instruments

HAND INSTRUMENTS

PRESENTED BY:FASAHAT AHMED BUTT

ROLL# 36GROUP: C

CLASSIFICATION

• Cutting instruments

• Non cutting instruments

CUTTING INSTRUMENTS

EXCAVATOR CHISELS OTHERS

1) ORDINARY HATCHET2) HOE3) ANGLE FORMER4) SPOON

1) CHISEL2) ENAMEL HATCHET3) GINGIVAL MARGIN TRIMMER

1) KNIVES2) FILES3) SCALERS4) CARVERS

NON CUTTING INSTRUMENTS

1) MIRROR2) PROBE3) TWEEZER

Diagnostic instruments Plastic instruments

Amalgam instruments

1) DYCAL APPLICATOR2) CEMENT SPATULA

1) AMALGAM CARRIER2) CONDENSER3) BURNISHER4) CARVER

MATERIALS USED

CARBON STEEL• More corrosion

tendency.• Harder than

stainless steel.• It loses keen edge

slower than stainless steel.

STAINLESS STEEL• Less corrosion

tendency.• Less comparatively.• It loses keen edge

quicker during much use.

PARTS OF HAND INSTRUMENTS

• Most of the instruments are composed of the following parts:

• Handle• Shank• Blade/Nib

HANDLE

• It is used to hold the instrument.• They are available in various sizes and

shapes.• It may be smooth or eight sided and

serrated.• On handle of the instrument, the

instrument formula and manufacturer’s name are written.

SHANK

• It connects the handle with the working point or nib of the instrument.• It is smooth, round or tapered.• It may be straight or bent for better

control of working point when the force is applied.• It has one or more angles to avoid

twisting of the instrument.

BLADE

• Working part of the instrument.

• Connected to the handle by shank.

• Each blade has a cutting edge that is the working end.

BLACK’S CLASSIFICATION• Black classified all instruments according

to:

• FUNCTION: Excavator.• MANNER OF USE: Hand condenser.• DESIGN OF WORKING END: Hatchet• SHAPE OF THE SHANK: Mono-angle, bin

angle, contra-angle.• These names were combined to form the

complete description of the instrument e.g, bin-angle spoon excavator

INSTRUMENT FORMULA

• Hand cutting instruments have formulas describing the dimensions and angles of working end. Placed on the handle as three or four figures.

THREE-NUMBER FORMULA

• For instruments in which the primary cutting edge is at a right angle to the long axis of the blade.

14-10-16

• 14: Width of the blade (in tenths of mm)

• 10: Length of the blade (in mm)• 16: Angle (in centigrade) made by

long axis of the blade and the long axis of the handle

FOUR-NUMBER FORMULA

15-95-10-7

• 15: Width of the blade (in tenth of mm)

• 95: Primary cutting edge angle (in centigrade)• 10: Length of the blade (in mm)• 7: Angle the blade makes with the long axis of the handle (in centigrade)

BEVEL

• Most cutting instruments have on the end of blade a single bevel that forms the primary cutting edge.• Additional two bevel extends from

primary cutting edge for the length of the blade.• This allows cutting in three dimensions.

CUTTING INSTRUMENTS

CHISELS:• Used primarily for cutting

enamel• Used with push motion.• They are grouped as: Straight, slightly curved or

bin-angle Enamel hatchets Gingival margin trimmer

ENAMEL HATCHET• Used primarily in anterior teeth, for

preparing retentive areas and sharpening internal line angles.

• To remove unsupported enamel• It comes as right and left types for use

on opposite sides of the preparation• Used with push, pull & vertical motion.

GINGIVAL MARGIN TRIMMER

• It is used to trim, smooth, and shape the gingival floor of a cavity preparation.

• It is also used for rounding or beveling of the axiopulpal line angle.

• Used with lateral scraping motion.

HOE

• Used to clean and smooth floor and walls in cavity preparation and forming line angles.

• Used with a pulling motion• Cutting edge or blade nearly perpendicular to

handle.

HOE VS HATCHET

• If the angle of the blade is less than 12.5 centigrade, it is mono-angle chisel & if it is more than 12.5 centigrade, it is hoe.

ANGLE FORMERS

• Primarily used for sharpening internal line angles and creating retentive features in dentine in preparation for gold restorations.

• Used in 3 motions vertical, push and pull.

SPOON EXCAVATOR

• Used to remove Soft carious dentine Temporary crowns Temporary cement in temporary restoration Permanent crown during try-in

• Discoid: Cutting edges are circular• Cleoid: Cutting edges are claw like

NON-CUTTING INSTRUMENTS

DIAGNOSTIC INSTRUMENTS

MOUTH MIRROR:

• To reflect light in the mouth• To retract lips, cheeks, and tongue• To provide indirect vision

DENTAL EXPLORER

• It is used to examine caries, calculus, furcation.

• Variety of sizes and typesOrbanPigtailShepherd’s hook

TWEEZER (cotton forceps)

• To grasp or transfer items and/or material into and out of the oral cavity.

• Plain or serrated tips.• Pointed or rounded tips

Locking tweezer

PLASTIC INSTRUMENTS

DYCAL APPLICATOR

• To place calcium hydroxide or glass ionomer in cavity preparation.

CEMENT SPATULA

• It is used for mixing cements and carrying materials.

AMALGAM INSTRUMENTS

• AMALGAM PLUGGER

• To carry and dispense amalgam for cavity preparation

• Single or double ended

AMALGAM INSTRUMENTS

CONDENSER

• Used to pack and condense amalgam into cavity preparation

• Single or double sided • Smooth or serrated ends• Round or flat• Small or large sizes

BURNISHER

• Used to smooth amalgam after condensing.

• Burnish amalgam.

• It is also used to contour matrix band before placement.

• It may be single or double ended.

CARVER

• To carve occlusal anatomy into amalgam restoration

• Single or double ended.

HAND INSTRUMENT TECHNIQUES

• Modified pen• Inverted pen• Palm and thumb• Modified palm and thumb

MODIFIED PEN

INVERTED PEN

PALM AND THUMB

MODIFIED PALM AND THUMB

REFERENCES

• Summit• Art and science• Google