1. HAND INSTRUMENT
Designed by : Ahmed maky

3. Contantes •Cleaning and Sterilization •Non cutting instrument
•Sharpening
Stationary sharpening
Mechanical sharpening
•Introduction
Definition
History
•Classification
Cutting instrument
Non cutting
•Instrument grasp
Modified pen. Inverted pen.
Palm and thumb.
Modified palm and thumb.
•Cutting instrument
MATERIALS
Hardening and Tempering
Heat Treatments
Design
Shank angles
Nomenclature
Formula
Bevels
•Cleaning and Sterilization
•Non cutting instrument
Amalgam condenser
Mouth mirror
Others
Designed by : Ahmed maky
•Cutting instrument applications
Excavators
Chisels

4. Introduction Definition : History :
It is hand-powered dental instruments.
History :
The early hand-operated instruments characterized by:
Large, heavy handles and inferior metal alloys in the blades.
cumbersome, difficult to use, and ineffective in many situations.
Designed by : Ahmed maky

5. there was no uniformity of manufacture or nomenclature, Many dentists made their own hand instruments in an effort to find a suitable instrument for a specific need.
effective sterilization was a problem.
Designed by : Ahmed maky
Designs of some early hand instruments

6. G.V. Black is credited with the first acceptable nomenclature and classification of hand instruments.
His classification system enabled both dentists and manufacturers to communicate more clearly and effectively in regard to instrument design and function.
G.V. Black

7. Classification
Designed by : Ahmed maky

8. Cutting Instrument remains bright under most conditions.
MATERIALS
Hand cutting instruments are manufactured from two main materials.
carbon steel
stainless steel
remains bright under most conditions.
Is harder than stainless steel.
Designed by : Ahmed maky
loses a keen edge during use much more quickly than does carbon steel
when unprotected, it will
corrode.

9. Tungsten carbide inserts or blades to provide
MATERIALS
Tungsten carbide inserts or blades to provide
more durable cutting edges (brittle). They may
be soldered to steel handles.
some instruments are made with carbide to
provide more durable cutting edges.

10. MATERIALS
Other alloys of nickel, cobalt, or chromium are used in the manufacture of hand instruments.
Stainless Steel
Carbon steel

11. Hardening and Tempering Heat Treatments:
MATERIALS
Hardening and Tempering Heat Treatments:
To gain maximal benefits from carbon steel or stainless steel, the manufacturer must submit them to two heat treatments: hardening and tempering .
Heat treatment Furnace

12. Heat treatment relieves strains and increases toughness. the tempering
MATERIALS
The hardening heat treatment hardens the alloy, but it also makes it brittle, especially when the carbon content is high.
Heat treatment relieves strains and increases toughness. the tempering
Heating or flaming of hand instruments
during dental use can alter the original
properties of the alloy and render it
unserviceable.

13. a- Blade or nib b-Shank c-Handle
Design
Most hand instruments composed of three parts :
a- Blade or nib
b-Shank
c-Handle

14. a- blade This is the working part of the instrument.
Design
a- blade
This is the working part of the instrument.
Begins at the point which terminates the
shank.
It is connected to the handle by the shank.
Each blade has a cutting edge which is the
working part of the instrument.
It is usually in the form of a bevel (acute
angle) that cuts into the tooth structure.
On non cutting instruments e.g. condensers
the part corresponding to the blade is called the nib or face.

15. b-shank Connect the handle to the working end of the instrument.
Design
b-shank
Connect the handle to the working end of the instrument.
Normally smooth, round and tapered.
Have one or more angles to avoid twisting of
the instrument.
Hand instruments must be balanced and sharp.
Balance allows for the concentration of
force onto the blade without causing
rotation of the instrument.

16. Shank angles: Balance is accomplished by designing the
angle of the shank so that the cutting edge
of the blade must not be off axis by more
than 1-2 mm.
Shank angles:
Mon-angle, bin-angle, triple angle.
Instruments with small short blades may be
monangle

17. Instruments with long blades may required
Design
Instruments with long blades may required
two or three angles in the shank to bring the
cutting edge near to the long axis of the
handle.
Such shanks are termed contra angled.

18. c- handle(shaft) It is the part grasped in the operator’s hand.
Design
c- handle(shaft)
It is the part grasped in the operator’s hand.
Perfectly straight, smooth or eight sided.
Serrated for better gripping and control of the
instrument.
Handles are in conjunction with the shank or
it may be separable.
Separate type is known as cone-socket
handle and allows for replacement of several
working ends e.g. mirrors and condensers.

19. cone-socket handle (mirror)
Design
mirror
cone-socket handle (mirror)

20. Black classified all instruments by name according to:
nomenclature
Black classified all instruments by name according to:
1. Function e.g. scaler, excavator.
2. Manner of use e.g. hand condenser.
3. Design of the working end e.g. spoon
excavator, sickle scaler
4. Shape of the shank e.g. mono-angle, biangle, contra-angle.
•These names were combined to form the
complete description of the instrument e.g.
binangle spoon excavator.

21. Hand cutting instruments have formulas
describing the dimensions and angle of
the working end.
These are placed on the handle using a
code of three or four numbers separated
by dashes or spaces (e.g ).
The first number indicates
the width of the blade in
tenths of a mm (e.g. 10 = 1 mm).
The second number primary cutting edge angle
measured from a line parallel to the long axis of
the handle in clockwise centigrade.

22. blade design with formula.
Instrument shank and
blade design with formula.

23. If the edge is perpendicular to the blade,
formula
If the edge is perpendicular to the blade,
this number is omitted resulting in a 3
numbers code.
The third number indicates the blade
length in mm (e.g. 8 = 8 mm).
The fourth number indicates the blade angle relative to the
long axis of the handle in clockwise centigrade e.g. (14)
Additional number on the handle is the manufacturer’s identification number.

24. Additional number should not be confused with the formula number.

25. Additional two secondary cutting edges that
Bevels
Most hand cutting instruments have on the end of the blade a single bevel that forms the primary cutting edge. Two additional edges,
Additional two secondary cutting edges that
extend from the primary cutting edge for the
length of the blade.
This allows cutting in 3 directions; facial and
lingual walls of the proximal cavity.
Chisel blade design showing primary and secondary cutting edges.

26. Bibeveled instrument have two bevels that form the cutting edge,
e.g. hatched excavator.

27. Single beveled instrument such as spoon excavator and gingival
Bevels
Single beveled
instrument such as
spoon excavator
and gingival
margin trimmer are
used with lateral
cutting movement.

28. planning or lateral cutting designated for right and left to
Bevels
Enamel hatchet also as a single beveled instrument used with direct cutting motion, a
planning or lateral cutting
designated for right and left to
the instrument formula.

29. The opposite is true for the left instrument of the pair.
Bevels
Right and left bevels
To determine this, the primary cutting edge is held down and pointing away.
If the bevel appears on the right, it is in the right instrument of the pair, when used it is moved from right to left.
The opposite is true for the left instrument of the pair.
One instrument is used for work on one side of the preparation and the other for the opposite side of the preparation.

30. The cutting edge is perpendicular to the axis of the handle
Bevels
The cutting edge is perpendicular to the axis of the handle
e.g. binangle chisel.
Instrument with slight blade curvature e.g.Wedelstaedt chisel.

31. Cutting instrument applications
Applications can be classified into:
written and designed by - Ahmed Maky
-Removal of caries and refinement of the internal parts of the preparation.
-Used primarily for cutting enamel.

32. CUTTING INSTRUMENT APPLICATIONS
written and designed by - Ahmed Maky

33. CUTTING INSTRUMENT APPLICATIONS
Hatchet excavator
It has the cutting edge of the blade directed in the same plane as that of the long axis of the handle and is bibeveled .
written and designed by - Ahmed Maky

34. CUTTING INSTRUMENT APPLICATIONS
Hatchet excavator
These instruments are used primarily on anterior teeth for preparing retentive areas and sharpening internal line angles, particularly in preparations for direct gold restorations .
written and designed by - Ahmed Maky

35. CUTTING INSTRUMENT APPLICATIONS
Hoe excavator
IT has the primary cutting edge of the blade perpendicular to the axis of the handle
written and designed by - Ahmed Maky

36. CUTTING INSTRUMENT APPLICATIONS
Hoe excavator
This type of instrument is used for planing tooth preparation walls and forming line angles. It is commonly used in Classes III and V preparations for direct gold restorations.
written and designed by - Ahmed Maky

37. CUTTING INSTRUMENT APPLICATIONS
Hoe excavator
Some sets of cutting instruments contain hoes with longer and heavier blades, with the shanks contra-angled. These are intended for use on enamel or posterior teeth.
written and designed by - Ahmed Maky

38. CUTTING INSTRUMENT APPLICATIONS Angle former excavator
It is mon-angled and has the primary cutting edge at an angle (other than 90 degrees) to the blade. It is available in pairs (right and left )
written and designed by - Ahmed Maky

39. CUTTING INSTRUMENT APPLICATIONS Angle former excavator
It is used primarily for sharpening line angles and creating retentive features in dentin in preparation for gold restorations.
It also may be used in placing a bevel on enamel margins
written and designed by - Ahmed Maky

40. CUTTING INSTRUMENT APPLICATIONS - the cutting edges are circular.
Spoon excavator
Its blades are slightly curved, the shanks may be bin-angled or triple-angled to facilitate accessibility.
written and designed by - Ahmed Maky
- the cutting edges are circular.
-the cutting edges are claw like.

41. CUTTING INSTRUMENT APPLICATIONS
bin-angled spoon
written and designed by - Ahmed Maky
triple-angled spoon

42. CUTTING INSTRUMENT APPLICATIONS
written and designed by - Ahmed Maky
Cleoid spoon

43. CUTTING INSTRUMENT APPLICATIONS
written and designed by - Ahmed Maky
Discoid spoon

44. CUTTING INSTRUMENT APPLICATIONS
written and designed by - Ahmed Maky

45. CUTTING INSTRUMENT APPLICATIONS
straight, slightly
curved, or bin-angle
The straight chisel has a straight shank and blade, with the bevel on only one side. Its primary edge is perpendicular to the axis of the handle.
written and designed by - Ahmed Maky

46. CUTTING INSTRUMENT APPLICATIONS
straight, slightly
curved, or bin-angle
The shank and blade of the chisel also may be slightly curved (Wedelstaedt design)
written and designed by - Ahmed Maky

47. CUTTING INSTRUMENT APPLICATIONS
straight, slightly
curved, or bin-angle
The shank and blade of the chisel also may be bin-angled .
written and designed by - Ahmed Maky

48. CUTTING INSTRUMENT APPLICATIONS
straight, slightly
curved, or bin-angle
The force used with all these chisels is essentially a straight thrust.
There is no need for a right and left type in a straight chisel, since a 180-degree turn of the instrument allows for its use on either side of the preparation.
written and designed by - Ahmed Maky

49. CUTTING INSTRUMENT APPLICATIONS
straight, slightly
curved, or bin-angle
The bin-angle and Wedelstaedt chisels have
the primary cutting edges in a plane perpendicular to the axis of the handle and may have either a distal bevel or a mesial (reverse) bevel.
written and designed by - Ahmed Maky

50. CUTTING INSTRUMENT APPLICATIONS
straight, slightly
curved, or bin-angle
The blade with a distal bevel is designed to plane a wall that faces the blade's inside surface
written and designed by - Ahmed Maky

51. CUTTING INSTRUMENT APPLICATIONS
The blade with a mesial bevel is designed to plane a wall that faces the blade's outside surface
written and designed by - Ahmed Maky

52. CUTTING INSTRUMENT APPLICATIONS
enamel hatchet
It is a chisel similar in design to the ordinary hatchet excavator except that the blade is larger, heavier, and is beveled on only one side
It has its cutting edges in a plane that is parallel with the axis of the
handle.
written and designed by - Ahmed Maky

53. CUTTING INSTRUMENT APPLICATIONS
enamel hatchet
It is used for cutting enamel and comes as right or left types for use on opposite sides of the preparation.
written and designed by - Ahmed Maky

54. CUTTING INSTRUMENT APPLICATIONS
gingival margin trimmer
Similar in design to enamel hatchet except the blade is curved.
Right and left types:
Right pair is for either a mesial or distal
gingival margins.
written and designed by - Ahmed Maky
Left pair is for a mesial or distal margins

55. CUTTING INSTRUMENT APPLICATIONS
gingival margin trimmer
written and designed by - Ahmed Maky

56. CUTTING INSTRUMENT APPLICATIONS
gingival margin trimmer
When the second number in the formula is , it is used for distal gingival margins.
When this number is 75-85, the pair is used
to bevel the mesial margins.
100 and 75 pairs for steep margins for inlay
preparation while for slight bevel in
amalgam preparations.
written and designed by - Ahmed Maky

57. CUTTING INSTRUMENT APPLICATIONS
gingival margin trimmer
Uses of GMT :
Beveling of the gingival margins of proximoocclusal preparations.
Beveling of the axiopulpal line angle. 1
written and designed by - Ahmed Maky 2

58. CUTTING INSTRUMENT APPLICATIONS
gingival margin trimmer
Performing a gingival lock (reverse bevel), placed on the gingival seat.
e.g. GMT 100 for the distal and GMT 75 for the mesial. 3
written and designed by - Ahmed Maky

59. Sharpening
cutting instrument
sharpening
The cutting edge of the hand instrument should always be kept sharp as dull
instruments may cause:
1. Loss of control.
2. More pain.
3. Prolonged time for the operative procedure.
4. Reduce the quality and precision of tooth
preparation.

60. cutting instrument
sharpening
sharpening equipment 1
Stationary sharpening stone e.g. Arkansas stone, silicon carbide.

61. 2 Mechanical sharpener; moves at low
sharpening 2
Mechanical sharpener; moves at low
speed while the instrument is held at the
opposite angle and supported by a rest
i.e. easier and less time consuming.
Mechanical sharpener

62. Instrument grasp There are four grasps used with the hand instruments:
Modified pen.
Inverted pen.
Palm and thumb.
Modified palm and thumb.
With each grasp proper rest and guard is
important. 1 2 3 4

63. 1. Modified pen grasp
It is similar to that used in holding a pen except
that the thumb, index and middle fingers contact
the instrument while the tips of the ring and little
fingers are placed on the working tooth as a rest..
The palm of the hand is facing away from the
operator.

64. pen grasp
Modified pen grasp

65. 2. inverted pen grasp inverted pen grasp
If the hand is rotated so that the palm
faces more toward the operator.
If is used in the lingual and labial surfaces
of anterior teeth.
inverted pen grasp

66. 3. Palm and thumb grasp (grasp of power)
The handle of the instrument is placed on the palm of the hand and grasped by all the
fingers while the thumb is free of the
instrument and rest on the nearby tooth of the same arch.
Palm and thumb grasp

67. 4. Modified palm and thumb grasp Modified palm and thumb grasp
The same as in palm and thumb grasp but the thumb is rested on the tooth being prepared.
Used in the upper arch.
Modified palm and thumb grasp

68. Instrument rest rests : A proper instrument grasp must include a firm
rest (support) to steady the hand during
operative procedures.
The support may be gained from hard tissue.
Soft tissue rest or too distant hard tissue rest
does not afford a reliable control.

69. Indirect rest may be gained by using the
index finger of the opposite hand to rest
on the shank of the instrument.
The operating hand rests on the opposite
hand which rests on stable oral structures.

70. Instrument guards
guards :
The use of interproximal wedges to protect soft tissues from contact with sharp rotary cutting instruments.

71. Cleaning and Sterilization Cleaning and Sterilization
Instrument Cleaning and Sterilization

72. Cleaning and Sterilization
All instruments need to be cleaned and thoroughly
dried before they are sterilized.

73. 1-Hand Scrubbing Advantages -Effective if performed properly
Disadvantages
-Increases chances for operator injury.
-Increases spread of contamination through splatter.
-Labor-intensive.
-Need proper care of scrub brush

74. 2-Ultrasonic Cleaning
Advantages
-Safer than hand scrubbing.
-Effectively cleans all instruments .
Reduces chances for spread of
contaminants through splatter.
-Allows for more efficient use of staff time
Disadvantages
-Microorganisms may accumulate in cleaning solution.
-Ultrasonic cleaning will not remove hardened Permanent cement. (Solution: remove cement while it is still soft.).

75. 3-Automated Washer Advantages -Safer than hand scrubbing.
-Reduces chances for spread of contaminants of contaminants through splatter and aerosols.
-Allows for more efficient use of staff time.
-Effectively cleans instruments.
Disadvantages
-Not all instruments are compatible with automated washers.
-Please see manufacturer's instructions for detailed requirements.

76. Sterilization
process by which an article, surface or medium is freed of all living microorganisms.
-Most dental offices have a designated area for instrument reprocessing that is separate from the dental treatment room. This is ideal, since cleaning, sterilizing and storing instruments in the same room where the delivery of patient care is provided increases the risk of cross-contamination.

77. -Some instruments and materials
are single use only.
- Single-use items should be
segregated in the operatory,
and those that are sharp
or otherwise pose a risk of injury
must be discarded into a sharps container .
-Items without risk, such as
a saliva ejector, can be thrown into the trash.
-To prevent accidental injury with the contaminated instruments, special handling should be used to transport the instruments to the cleaning and sterilization area.

78. -Although heavy-duty gloves (utility gloves) may feel more awkward than examination gloves, they provide extra protection while handling instruments during the cleaning, rinsing, drying, packaging and sorting procedures that take place during instrument reprocessing
utility gloves

80. 1-Steam preasure strillization
(autoclaving)
-Sterilization with steam under pressure is performed in a steam autoclave .
-For a light load of instruments, the time required at 250'F (121° C) is a minimum of 15 minutes at 15 lbs of pressure.
-Time for wrapped instruments can be reduced to 7 minutes if the temperature is
raised to approximately 273° F (134° C) to give30 pounds of pressure.

81. An example of a steam pressure sterilizer (autoclave)

82. Advantages of Autoclaves.
-Autoclaving is the most rapid and effective method for
sterilizing cloth surgical packs and towel packs.
-Automated models are available.
-although they still can be misused or fail almost as often as nonautomated ones; they must be evaluated
with a biologic spore test monitoring system.

83. Disadvantages of autoclaves
-Items sensitive to the elevated temperature can not be autoclaved.
-Autoclaving tends to rust carbon steel instruments.

84. 2-CHEMICAL VAPOR PRESSURE STERILIZATION (CHEMICLAVING )
-Sterilization by chemical vapor under pressure is performed in a Chemiclave.
-Chemical vapor pressure sterilizers operate at 270° F (131° C) and 20 pounds of pressure.
-They are similar to steam sterilizers and have a cycle time of approximately half an hour.

85. Advantages of Chemiclaves.
-Carbon steel and other corrosion-sensitive burs, instruments, and pliers are said to be sterilized without rust or corrosion.
Disadvantages of Chemiclaves.
- Items sensitive to the elevated temperature will be damaged.
-Instruments must be lightly packaged in bags obtained from the sterilizer manufacturer.
- Towels and heavy cloth wrappings of surgical instruments may not be penetrated to provide sterilization.
- Routinely use biologic spore test monitoring strips to confirm heat penetration of heavy packs before use.

86. Chemical vapor pressure sterilizer (Chemiclave)

87. 3. Dry heat sterilization (dryclave)
Is an excellent means of sterilization sharp instrument but rubber and plastic material can not be sterilized by this method .
-Dry heat sterilizers for use in dental offices are available, but all that is necessary is an oven that will maintain a temperature of 160°C(320°F)
-It imperative that all debris be removed from an instrument before it placed in a dry heat sterilizer .
*Holding period : 160°C(320°F),1 hour .

88. Advantages of this method
1-is an excellent means of sterilization sharp instrument.
2-instrument not corrode or rust.
Disadvantages
1-a lower temperature or a shorter period will not produce the desired result .
2-The higher temperature of a dry-heat sterilizer means that paper will scorch and plastic will melt.
3-some hand pieces can not be sterilized by this method

89. Cox rapid heat transfer dry heat sterilizer

90. 4-ETHYLENE OXIDE STERILIZATION
-Ethylene oxide sterilization is the best method for sterilizing complex instruments and delicate materials.
-ethylene oxide gas is toxic for all viruses and bacteria at room temperature on exposure for hr at elevated temperature .
-this method requires rather expensive equipment .

91. Room temperature ethylene oxide sterilizer

92. BOILING WATER
*Boiling water does not kill spores and cannot sterilize
instruments. However, heat can reach and kill blood borne pathogens in places that liquid sterilants and disinfectants used at room temperature cannot reach.
*Boiling is a method of high-level disinfection that has been used when actual sterilization cannot be achieved (e.g., in case of a sterilizer breakdown)

93. New methods of sterlization
**Various new methods of sterilization are under investigation and development.
-The microwave oven has major limitations for sterilizing metal items, by either damaging the machine or not reaching all sides of the instruments.
microwave oven

94. -Ultraviolet light is not highly effective against RNA viruses such as HIV and is not very effective against bacterial spores
Ultraviolet light

95. -Incomplete exposures of all surfaces and poor penetration of oil and debris are other limitations.
- Ultraviolet irradiation may be useful for sanitizing room air to help control tuberculosis bacteria .

96. Instrument storage in dental cabinet
1-After the instrument are sterilized, they are placed in proper place in a dry condition .
2-The portions of dental cabinet designated for hand instrument contain grooved glass or metal trays.
3-These instrument containers must be kept in clean and aseptic condition.
4-hey should also contain protective medium for
cutting edges of the instrument .

97. The purpose of this :

98. Effects of Sterilization
Sterilizing carbon steel instruments by any of (cold disinfection, boiling water, steam under pressure (autoclave) causes discoloration, rust, and corrosion.
minimizing these problems are available.
1-electroplate the instrument. This affords protection, except
on the blade, where use and sharpening remove the plating.

99. 2- use of rust inhibitors, which are soluble alkaline compounds.
3-is to remove the instruments promptly at the end of the recommended sterilizing period, dry them thoroughly, and place them in the instrument cabinet or on the tray setup.

100. Non cutting instrument

101. 1. Amalgam condenser
It is a dental instrument used for compacting silver amalgam while in a plastic state, used for restoring teeth to a natural contour.
Condensers come in single- and double-ended designs. They have various shaped and sized working ends, which may be smooth or serrated.

102. Various Amalgam condensers

103. 2. mouth mirror its most important functions are:
mouth mirror or dentist's mirror is an instrument used in dentistry.
The head of the mirror is usually round, and the most common sizes used are the No. 4 and No. 5. A No. 2 is sometimes used when a smaller mirror is needed, such as when working on back teeth with a dental dam in place.
its most important functions are:
allowing indirect vision by the dentist .
reflecting light onto desired surfaces.
retraction of soft tissue.

106. 4. others
A. Carvers.
After the amalgam is condensed, it must then be carved to approximately the same original tooth structure.
Carvers have sharp cutting edges that are used to shape, form, or cut tooth anatomy into amalgam restorations.

107. Carvers

108. B. Burnishers.
When the carving is complete, the dentist may use burnishers.
used to
smooth and polish the restoration.
remove scratches left on the amalgam surface by a carving instrument.

109. Burnishers

110. Disposable brush and handle.
C. disposable brush
used with etching and bonding procedures associated with composite resins is a disposable brush with a reusable handle.
aiding in good infection control practices.
Disposable brush and handle.

111. Thanks
for
attention