lecture 2, instrumentation (slides)

8/3/2019 Lecture 2, Instrumentation (Slides)

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Instrumentation


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Hand Instruments

Carbon steel + Stainless steel

Carbon steel is brittle and

susceptible to corrosion

Stainless steel dose not tarnish or

corrode ,but it will not maintain a

sharp cutting edge

Most are double-ended

Cutting & None-cutting


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Parts of the Hand Instruments

a. Blade or nib

Working end

Form 45 angle with

the shank

b. Shank

Connect handle

to bladeC. Handle

Hold, stabilize

& control the instrument


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Hatchet ( enamel

hatchet)

Double-ended form

Right and left cutting

ends to use in both sides

of the preparation Removal of unsupported

enamel


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Gingival Margin Trimmer Curved blade

Mesial & distal gingivalmarginal trimmer


ends

Mainly for trimming

gingival margins


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Spoon Excavators


spoons

They are used forremoval of carious tooth

structure and soft dentin

Different shapes


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Amalgam condenser To compress amalgam in

all areas of the

preparation

May be also used to

adapt resin composite

material


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Carvers:

Are used to shape soft

amalgam

Cleoid-discoid carver for

carving of occlusalsurfaces


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Burnishers: To burnish (smooth)

amalgam restorations To shape the metal

matrix band

To condense amalgam at

the margins To adapt composite in

posterior resin compositerestorations


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Amalgam Carrier


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Amalgam Carrier


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Amalgam Carrier


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Other Instruments


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Rotary Instruments

Air-driven handpieces

Low speed handpiece

10,000-15,000 rpm

For removal of caries

and polishing of

restorations

Different attachments:latch or friction grip


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High speed handpiece

up to 100,000 rpm

Cavity preparation


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Burs

Burs are milling devices and function by chipremoval of tooth structure.

Tungsten carbide bur.

Their heads are composed of a number of metalcutting blades and must rotate incounterclockwise direction .


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Burs

Parts of the bur:

Shank: Part that fits on

the handpiece Neck: Connect the head

to the shank, transmit

forces to the head Head: The working part


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Basic Burs Head Shapes

Classification

Head shape

Number


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Recommended Burs


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Finishing Burs

Come in many sizes &

shapes

Have more blades thannormal bur and the blades

are set much closer together

Finishing & polishing

operations for amalgam &resin composites

restorations


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Instrument Grasps

Pen grasp & modified

pen grasp

Palm and thumb grasp

lecture 2, instrumentation (slides)

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