DENTAL INSTRUMENTS DR.LINDA MEHAR

INSTRUMENTS: The term instrument refers to a tool or device used for specific purpose or procedure. The dental operator must have complete knowledge of the purpose and applications of instruments required to perform dental procedures 1\instruments available 2\the purpose of instrument 3\the position and manner of use

MATERIALS USED CARBON STEEL STAINLESS STEEL Advantages: Harder than stainless steel. It loses sharpness slower than stainless steel. Disadvantage: More corrosion (rusting) tendency during sterilization. Advantages: Less corrosion (rusting) tendency during sterilization. Disadvantages: Less hard comparatively. It loses sharpness quicker during much use.

SOME INSTRUMENTS ARE MADE OF CARBIDE TO PROVIDE MORE DURABLE CUTTING EDGE. OTHER ALLOYS: alloys of nickel , cobalt or chromium are used

CLASSIFICATION 1\HAND INSTRUMENTS A\CUTTING INSTRUMENTS B\NON CUTTING INSTRUMENTS 2\ROTARRY INSTRUMENS MAINLY CUTTING INSTRUMENTS

hand instruments

Definition: Hand instruments are those instruments that are used manually without a power source

HAND INSTRUMENTS ARE COMPOSED OF THREE PARTS: 1\Handle. 2\Shank. 3\working end (Blade Or nib).

1\HANDLE It is the part of the instrument grasped by the operators hand Handles are in conjunction with the shank or it may be separated Separate type handles allows for replacement of several working ends e.g. mirrors and condensers

2\SHANK The part that Connect the handle to the working end Usually smooth, round and tapered Have one or more angles

3\Working end It is the working part of the instruments Begins at the point which terminate the shank On cutting instruments it is called (blade) On non cutting instruments it is called(nib)

CLASSIFICATION OF HAND INSTRUMENTS One of the earliest classification of instruments was proposed by G.V. Black G.V. Black classified all instruments based on the use of the instruments to: Non-cutting instruments. Cutting instruments.

NON CUTTING INSTRUMENTS Diagnostic instruments Plastic instruments Amalgam instruments 1) MIRROR 2) PROBE 3) TWEEZER 1) DYCAL APPLICATOR 2) CEMENT SPATULA 1) AMALGAM CARRIER 2) CONDENSER 3) BURNISHER 4) CARVER

DIAGNOSTIC INSTRUMENTS

1\DYCAL APPLICATOR 2\SPATULA PLASTIC INSTRUMENTS

AMALGAM INSTRUMENTS 1\AMALGAM CARRIER 2\CONDENCERS 3\CARVERS 4\BURNISHERS AMALGAM INSTRUMENTS

CUTTING INSTRUMENTS 1) CHISEL 2)ENAMEL HATCHET EXCAVATOR CHISELS OTHERS 1)ORDINARY HATCHET 2) HOE 3) ANGLE FORMER 4) SPOON 1) CHISEL 2)ENAMEL HATCHET 3) GINGIVAL MARGIN TRIMMER KNIVES FILES SCALERS CARVERS

EXCAVATORS

CHISELS

OTHER CUTTING INSTRUMENTS 1\FILES 2\KNIFES 3\SCALERS 4\CARVERS OTHER CUTTING INSTRUMENTS

NOMENCLATURE Black classified all instruments by name according to 1\function (e.g. scalar ,excavator) 2\manner of use (e.g. hand scalar) 3\design of the working end (e.g. spoon excavator) 4\shape of the shank (e.g. mono angle –bi angle-contra angle) These names were combined to form the complete description of the instrument (e.g. bi angled spoon excavator)

INSTRUMENTS FORMULA HAND CUTTING INSTRUMENTS HAVE FORMULA’S DESCRIBING THE DIMENTIONS AND ANGLES OF THE WORKING END These are placed on the handle using a code of three or four numbers separated by dashes(e.g. 10-85-8-14)

This formula consists of three units: 1\ Blade width: expressed in tenth of millimeters. 2\Blade length: expressed in millimeters. 3\ Blade angle: expressed in centigrade ,this represents the angle of the blade relative to the long axis of the handle of the instrument.

For instruments in which the primary cutting edge is at a right angle (90) to the long axis of the blade the formula composed of three digits 10-14-16

if the primary cutting edge is other than 90 degree to the long axis of the blade then the Primary cutting edge angle(in centigrade) is added to the formula(four digits formula) This number is placed in the second position of the formula 1-blade width 2-primary cutting edge angle 3-blade length 4-blade angle

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