1. DENTAL INSTRUMENTS
DR.LINDA MEHAR

2. 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

3. 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.

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

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

7. hand instruments

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

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

11. 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

12. 2\SHANK The part that Connect the handle to the working end
Usually smooth, round and tapered
Have one or more angles

14. 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)

17. 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.

18. 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

19. DIAGNOSTIC INSTRUMENTS

20. 1\DYCAL APPLICATOR 2\SPATULA
PLASTIC INSTRUMENTS

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

22. 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

23. EXCAVATORS

24. CHISELS

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

26. 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)

27. 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 )

28. 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.

30. 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

31. 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

33. Thank you