A detailed description of dental handpieces with their functions and advantages, disadvantages, and comparisons.

1. ROTARY INSTRUMENTS IN
OPERATIVE DENTISTRY…
By Dr. Gayatri Majumder
2nd year PGT
Part-1
1

2. CONTENTS…
Introduction
 Historical development
 Classification of dental handpiece
Advantage and disadvantage of speed
 Characteristics of rotary instrument
New advancement
 Maintenance of instruments
2

3. INTRODUCTION
• Removal and shaping of tooth structure is an essential part
of restorative dentistry.
• Initially this was difficult process accomplished entirely by
the use of hand instruments .
• In order to perform the intricate and detailed procedure
associated with operative dentistry , the dentist must have a
complete knowledge of the purpose, availability and
application of the many instrument required.
3

4.  The term ‘Rotary’ applied to a group of instruments that turns on
an axis to perform work.
 This work includes:
1) cutting
2) Abrading
3) Burnishing
4) finishing and polishing of tooth
tissues and various restorative materials.
4

5. WHY ROTARY….???????
To remove maximum hard tissue with Minimum effort and
minimum time.
Advantage – control
- Less fatigue
- Greater patient acceptance
- Bur size decreased
5

6. ADVANTAGES OF ROTARY
INSTRUMENTS…
 Time: because of high speed, time required very less.
 Energy: compared to early rotary instruments- make use of energy other than
manual energy mainly reduces operator fatigue.
 Pressure -in case of hand instruments- unwanted high pressure or force is
applied for removal of tooth substance where as in high speed of rotary- no
pressure or negligible pressure can be felt.
 Precision : by attaining good control over these instruments- tooth structure
removed and shaped precisely
6

7. 7

8. HISTORY…
• A 14000- year-old adult male skull which was found in Italy in
late 1980’sThey discovered signs that the biting surface of one
rotten tooth in the jaw had been deliberately scoured and
scraped with a tool - perhaps in an effort to remove the decayed
tissue.
• There is evidence that Maya(250 AD-900 AD) and other ancient
cultures used primitive ‘Bow drills’ and other devices.
• Used to prepare round ornamental cavities.
8

9. HISTORY…
9
14000 years old adult
male skull
Dental ornamentation by Mayan
civilization

10. HISTORY…
Prehistoric man used sharp pieces of flint for trephining
holes in bones.
Hippocrates in 350 B.C. described a drill driven by a cord
wound around a shaft.
 Celsus (25 B.C. –50 A.D) described two kinds of drillers or
“Terebra”. One with a guard to prevent it from sinking deep
into the tissues and the other one was similar to a carpenter’s
drill.
10

11. HISTORY…
11
Sharp
instrument
of flint
Drill driven
by cord
Some early drills
from the
time of
Hippocrates.

12. HISTORY…
In 2A.D. Cladius Galenius a celebrated physician reports of
Archigenes an eminent surgeon of Asia minor and practicing in
Rome successfully treated tooth ache by opening the tooth with a
trephine.
Galen (130 –200 A.D) modified Celsus’s “Terebra” and called it
“Terebraabatista” or “Modiolus”. Lubrication was done with olive
oil or milk or by dipping in cold water.
12

13. HISTORY…
13

14. HISTORY…
Abulcasis (936 – 1013 A.D) described a boring instrument
“Incisura”.
Perre Fauchard “Father of Dentistry” in his book “The Chirurgien
Dentiste “ in 1728 described the first dental rotary instrument of
modern times. It was known as the “Bow Drill” could be rotated at
300rpm and was later on modified into the “Scranton’s drill” which
could cut by rotating in either direction.
14

15. HISTORY…
15
Instruments
described by
Abulcasis

16. HISTORY…
In 1831 dental chair was introduced.
In 1838 John Lewis made a hand held drill.
 Dr. West Cott in 1846 used “Fingerings” with drills. Taft called
them “Bur Drills”.
16

17. HISTORY…
17
Glenner, Richard A. “Development of the
Dental Drill.” The Journal of the American
Dental Association, vol. 88, no. 4, 1974,
Hand held drill
Fingerings with drill

18. HISTORY…
Drill stocks, bur chucks or bit holders – forerunner of the present dental
handpiece.
eg: -Cheavlier drill stock
 Merry’s drill stock
 ‘Chevalier drill stock” was hand powered like an egg-beater.
18

19. HISTORY…
19
Cheavlier drill stock Merry’s drill stock

20. HISTORY…
Tomes in 1859 described three types of burs.
1. Rose head: a short shank bur inserted in a crutch rotated
between thumb and index finger supported at the base of the
thumb.
2. Long hand bur: teeth are cut for same distance along the shaft
and it is mounted in a handle.
3. Long steel shaft with two cutting blades.
20

21. HISTORY…
21
Rose head bur Long steel shaft bur

22. HISTORY…
America in 1860s began mass production of burs from carbon
steel. The earliest burs had limited lateral and end cutting action.
The diameter varied form 1/32” to 1/5”. These were particularly
used for small and medium sized varieties. These carbon steel burs
were called “Small milling cutters”.
22

23. HISTORY…
23

24. HISTORY…
 In 1871 Morison’s foot engine was introduced. Morrison modified
and adapted the dental foot engine from the singer sewing machine.
Cutting procedure was carried out with a power source
A speed of 700 rpm was obtained.
24

25. HISTORY…
25
Glenner, Richard A. “Development of the
Dental Drill.” The Journal of the American
Dental Association, vol. 88, no. 4, 1974,

26. HISTORY…
In 1873 Coxeter used an electric engine with a speed of 1000 rpm.
This is the predecessor of the modern micromotor. This was held
in hand and connected to a coil. The motor was open and the
spindle of the motor was connected with the hand piece.
In 1874 the electric motor hand piece was invented by S.S white
and later he also pioneered the invention of various carbon steel
burs and hand pieces.
26

27. HISTORY…
27
Glenner, Richard A. “Development
of the Dental Drill.” The Journal of
the American Dental Association,
vol. 88, no. 4, 1974,

28. HISTORY…
In 1883 rotary power from an electric engine was transferred to
the straight hand piece by a belt that ran over a series of pulleys
and a three-piece extension cord arm. A variable rheostat was
used as a foot control.
Rotary cutting instruments were inserted into the chucking
mechanism at the front of the handpiece.
The desired angle handpiece is attached to the front of the
straight hand piece and a shaft and gears inside the angle section
produce rotation of the working instrument.
28

29. HISTORY…
29
Glenner, Richard A. “Development
of the Dental Drill.” The Journal of
the American Dental Association,
vol. 88, no. 4, 1974,

30. HISTORY…
In 1891 Edward G. Acheson an American invented and produced
carborundum and carborundum tools were introduced.
 In 1901 hand piece with forward (clockwise) and reverse
(anticlockwise) direction of rotation and burs for each type
movement were brought into use.
30

31. HISTORY…
In 1910 Emile Huet a Belgian perfected an electric engine to give
a speed of 10,000 rpm.
In 1935 diamond abrasives were introduced and W.H Drendel
introduced the process of galvanized bonding of diamond
powder to copper blanks and used at a speed of 5,000 rpm.
31

32. HISTORY…
In 1947 Tungsten carbide was introduced and S.S White in 1948
made tungsten carbide burs which were used at a speed of 12,000
rpm.
32

33. HISTORY…
In 1949 Walsh and Symons used diamond points at a speed of
70,000 rpm.
33

34. HISTORY…
In 1950 ball bearings were used in contra angel handpieces.
 In 1951 air abrasive technique was introduced.
 In 1953 Nelson produced a Hydraulic driven turbine angle
handpiece of speed, 60,000 rpm
34

35. HISTORY…
35
Glenner, Richard A. “Development of
the Dental Drill.” The Journal of the
American Dental Association, vol. 88,
no. 4, 1974,
Handpiece
containing
bearings
Air abrasive
technique
Hydraulic driven
turbine

36. HISTORY…
In 1955 Page-chayes introduced first belt-driven angle handpiece
to operate successfully at speeds over 100,000 rpm.
All gears were eliminated by having a small belt run inside the
handpiece sheath over ball bearing pulleys in the angle sections.
 Improved models -Page-Chayes 909 and the Twin 909
36

37. HISTORY…
37
Belt driven handpieces

38. HISTORY…
In 1955 Turbo-jet was designed as a compact
mobile unit that required no outside plumbing
or air connections.
Only a source of electricity was need.
A sound proof cabinet contained a motor,
water pump, water reservoirs and necessary
plumbing for water circulation. Water was
conveyed to and from the hand piece by co-
axial type plastic tubing
38

39. HISTORY…
The small inner tube carried water under
high pressure to rotate a turbine in the
handpiece head and the larger outer tube
returned the water to the reservoir for re
circulation.
39

40. HISTORY…
In 1960 ultrasonics were used for hard tooth structure removal.
In 1961 air turbine straight handpiece was introduced.
In 1962 air turbine angle handpiece with air bearings were
introduced.
40

41. HISTORY…
41
Ultra sonic
instruments
Air turbine contra
angle handpiece
Air turbine straight
handpiece

42. HISTORY…
A small compact unit consists of a handpiece,
control box, foot control and various connector
hoses.
 When the foot control is activated, compressed air
flows through the control box and is carried by a
flexible hose to the back of the handpiece.
 From here the air is directed to the head of the
handpiece and is blown against the blades of a
small turbine to produce Rotation, while the
greater part is exhausted at the back of the
handpiece or returned to the control box.
42

43. HISTORY…
Most modern angled handpieces also include fibreoptic lighting
of the cutting site.
43

44. HISTORY…
Earlier units were water driven and later came the air driven units.
Have free running speed of 300,00 rpm but lateral loads during cutting can
reduce it to 200,00 rpm.
Excellent safety feature
Advantages: simple, ease of control, patient acceptance, versatility.
Disadvantages: low torque & power output makes them unsuitable for finishing
& polishing purposes.
Solutions: Straight handpieces which provided high torque & low speed
operation.
44

45. RECENT DEVELOPMENTS:
Allow repeated sterilization
Smaller head size
More Torque
Lower noise
Better chucking mechanism
Fiber-optic lighting of the cutting site.
Contemporary air turbine handpiece
45

46. EVOLUTION AT A GLANCE…
46

47. EVOLUTION AT A GLANCE…
47

48. CLASSIFICATION OF ROTATING
INSTRUMENTS:
According to speed :
( According to Sturdevant )
High speed range or ultra- 100,000 to 300,000 rpm
Intermediate speed range- 12000 to 100,000 rpm
Low speed range- Below 12000 rpm
48

49. CLASSIFICATION OF ROTATING
INSTRUMENTS
(Acc. to Marzuok)
Ultra low speed : 300-3000 rpm
Low speed : 3000-6000 rpm
Medium high speed : 20,000-45,000 rpm
High speed : 45,000-100,000 rpm
Ultra high speed : 1000,000 and above
49

50. CLASSIFICATION OF ROTATING
INSTRUMENTS
(Acc. to Charbonneau)
Conventional or low speed : below 10,000 rpm
Increased or high speed : 10,000-150,000 rpm
Ultra speed : Above 150,000 rpm
50

51. CLASSIFICATION OF ROTATING
INSTRUMENTS
(Gilmore- 3 Edition )
Regular speed- 500-6000 rpm
 Ultra speed- 200,000 rpm
51

52. SO MANY SPEEDS – WHICH IS THE
RIGHT ONE TO USE ???
52

53. LOW SPEEDS…
Used for..
cleaning teeth
caries excavation
finishing & polishing
Advantages…
better tactile sensation
less chances of overheating cut surfaces.
53

54. LOW SPEEDS…
Disadvantages…
More heat production
Vibration
Time consuming
Inefficient for cutting
Burs have tendency to roll out proximal margin or tooth surface.
Carbide burs do not last long.
54

55. CHARACTERISTICS OF ROTARY
INSTRUMENTS
Speed
Speed refers not only to revolutions per minute, but also to the surface feet
per unit time of contact that the tool has with the work to be cut. It is
important to consider the size of the working tool in relation to the speed of
operation.
A rotary tool should be large in diameter when used with low speeds to
approach the optimum surface feet per unit time.
In ultra high speed range, the diameter of cutting tool should be reduced to
approximate the limits of maximum cutting efficiency.
55

56. CHARACTERISTICS OF ROTARY
INSTRUMENTS
• Pressure
Pressure is resultant effect of two factors under the control of dentist.
1. force : the gripping of the handpiece and its positioning and application to the
tooth.
2. Area : the amount of surface area of cutting tool in contact with the tooth surface
during a cutting operation.
P=F/A
It has been observed that low speed requires 2-5 pounds force, high speed requires
less force i.e 1 pound and ultra high speed still less force
i.e.1-4 ounces
Higher speed->less fatigue to operator-greater comfort to patient
56

57. CHARACTERISTICS OF ROTARY
INSTRUMENTS
• Heat production
It is directly proportional to;
1. Pressure
2. RPM
3. Area of tooth in contact with the tool
At temp of 130 F tooth pulp is permanently damaged .At 113 F inflammatory
responses that could result in pulpitis and eventual pulp necrosis is seen.
Higher speed call for less force and if coolants are used, heat production could
be eliminated or at least minimized
57

58. CHARACTERISTICS OF ROTARY
INSTRUMENTS
• Vibration
Vibration is not only a major annoying factor for the patient, but it also causes
fatigue for operator, excessive wear of instruments and most importantly, a
destructive reaction in the tooth and supporting tissue.
Vibration is a product of the equipment used and speed of rotation.
The equipment primarily the hand pieces and the revolving cutting tools
The deleterious effects of vibration are two fold in origin
1. Amplitude
2. Undesirable modulating frequencies
58

59. CHARACTERISTICS OF ROTARY
INSTRUMENTS
1. Amplitude
An wave of vibration consists of frequency and
amplitude.
At low speed, the amplitude is large but the
frequency is small. At higher speeds the reverse is true.
By increasing the operating speed the amplitude and
its effects are reduced as well as its sequelae.
Higher RPM s produce less amplitude and greater
frequency of vibrations. As a result, perception will be
lost in the ultra high speed ranges of 1,00,000 RPM or
more
59

60. CHARACTERISTICS OF ROTARY
INSTRUMENTS
2. Undesirable modulating frequency
The second deleterious effect of vibration is caused by
improperly designed, or poorly maintained equipments .
Improper equipment use or care allows modulating
frequencies to be established so that a series of vibrations are
perceived by the patient and the dentist. The end result is
again apprehension in the patient,
fatigue for dentist and accelerated wear of cutting
instruments
To eliminate these, The operator should supply himself with
true running energy source, centrically cutting tools and
handpieces that run at high speed.
60

61. CHARACTERISTICS OF ROTARY
INSTRUMENTS
Patients reaction
The factor that cause patients apprehension are
Heat production
Vibrational sensation
Length of operating time
Number of visits
The proper understanding of the instruments and the speed at which it is being used,
the use of coolants,
intermittent application of a tool to the tooth;
sharp instruments aid in minimizing patients discomfort and unnecessary irritant to oral tissue
61

62. CHARACTERISTICS OF ROTARY
INSTRUMENTS
Operator fatigue
The major cause of fatigue is
Duration of operation
Vibration produced in the handpiece
High speed rotary instrumentation minimizes fatigue by decreasing both the
vibrations and the time of the operation.
62

63. INSTRUMENTS DESIGN
Instrument design for rotary instrumentation should be evaluated
in 2 parameters .
1. Handpiece
2. Cutting tool itself
63

64. CLASSIFICATION OF DENTAL HAND
PIECES
According to Speed:
Conventional <10,000 rpm
Intermediate 10,000-1,00,000 rpm
High /Ultra high >1,00,000 rpm
According to Applications:
Straight
Contra angle
Right angle
Type of power mechanism: Belt devices
Gear devices
Direct motor devices
Water driven
Air driven
64

65. CLASSIFICATION OF DENTAL
HANDPIECES
65
Straight angle Contra angle Prophy angle

66. DENTAL HANDPIECES
The following criteria should be used in evaluating
handpieces :
a. Friction:
 Friction will occur in the moving parts of handpiece;
especially the turbine.
 Heat from friction is prevented by handpieces
equipping with bearings: ball bearing, needle
bearings, glass and resin bearings, etc
66

67. DENTAL HANDPIECES
b. Torque
 Torque is the ability of the handpiece to
withstand lateral pressure on the revolving
tool without decreasing its speed or
reducing its cutting efficiency.
 Torque is dependent upon the type of
bearing used and the amount of energy
supplied to the handpiece.
67

68. DENTAL HANDPIECES
C. Vibration
 While some vibration is unavoidable, care should be
taken not to introduce it unnecessarily.
 Excessive wear of the turbine bearings, will cause
eccentric running which creates substantial vibration .
68

69. DENTAL HANDPIECES
Classified according to their driving mechanism
GEAR driven handpiece
 Rotary power is transferred by a belt which runs from an electric engine.
 Power is transferred from the straight handpiece by a shaft and gears
inside the angle section.
 Capable of working at variable speeds though they work best at low speeds.
69

70. DENTAL HANDPIECES
70

71. DENTAL HANDPIECES
WATER driven handpiece
 discovered in 1955
 Operates at speed of1,00,000rpm
 water is transported at high pressure to rotate the turbines
 Quite in nature and highest torque.
 BELT driven handpiece
 introduced in 1955
 operates at speed.>1,00,000 rpm
 Excellent performance and great versatility
 AIR driven handpiece
 introduced in 1957
 operates at speed of approx 3,00,000rpm
71

72. DENTAL HANDPIECES
72
Water Driven Belt Driven Air Driven

73. DENTAL HANDPIECES
• Electric handpiece
• 1.CONSTANT SPEED AND TORQUE-
 Electrical handpiece maintains constant speed of 200,000 rpm.
 The constant torque of electric handpiece eliminates the stalling or
reduced speed experienced when using an air driven to cut through
crown.
• 2.CONCENTRIC CUTTING-
 The constant torque produces a concentric cutting motion as speed is
maintained.
 The feather motion needed when using an air-driven handpiece
results in varying degrees of irregularities at the margin of a
preparation.
 The gears of the electric handpiece hold the bur in a locked position to
prevent the wobble or vibration of the bur that is often experienced
when using an air-driven handpiece.
 Constant torque and stabilization of the bur allow a concentric motion
that ultimately produces a smooth, even margin.
73

74. DENTAL HANDPIECES
3.REDUCED NOISE –
 While no handpiece is truly quiet, the electric handpiece produces a much
quieter noise than the high-pitch sound of the air-driven systems.
4.TURBINE-FREE ATTACHMENTS –
 Failure of the turbine is the leading cause of malfunction in an air-driven
handpiece. Electric handpiece attachments utilize gears rather than turbines.
 The use of gears allows the handpiece to maintain constant torque and
more concentric cutting. While most attachments have two gears, some
provide three gears to better distribute the load.
 This feature reduces the wear on the bearings, resulting in less failure over
time
74

75. DENTAL HANDPIECES
 6.MANUAL CONTROL OF OPERATING SPEED
 . The motor speed is easily adjusted to provide precise control of the
rotation of the bur for a specific procedure. Most current systems offer a
digital display of the current operating speed
7.One Motor/Several Attachments
One motor is used for high-speed and slow-speed attachments with an
operating range of 70-200,000 rpm. A large variety of attachments are
available for high-speed, slow-speed, endodontic and implant placement
procedures.
75

76. PARTS OF DENTAL HANDPIECES..
1. Air turbine ( in case of air rotor
handpiece)
2. Micromotor( in case of micromotor
handpiece)
3. couplings or tubing system
4.Chucking system
76

77. PARTS OF DENTAL HANDPIECES..
Handpieces are operated by
1.Air pressure that is supplied by a compressed air transmitted through a compressor(
Air rotor handpiece)
2.Directly by an electric micromotor(micromotor handpiece)
High speed is operated by- compressed air (Air turbine or air rotor handpiece)
Slow speed operated by either a compressed air or directly by an electric motor.
77

78. DENTAL HANDPIECES
• AIR TURBINE
 This has high speed but reduced torque.
 Mechanism-
 High speed revolutions causes wear of
supporting bearing . so, the rotating turbine
and cutting bur suspended in air bearings.
When overpowered , these bearings crash
due to the lateral forces.
 Miniature ball –races to suspend the motor.
Provides improved torque abilities and hence
can not be stalled.
78

79. DENTAL HANDPIECES
79

80. DENTAL HANDPIECES
• MICRO-MOTORS
 It is necessary to have a slower speed motor to
remove soft caries, finishing and polishing ( 500 rpm
to 1,00,000 rpm)
 High torque with low speed is essential to prevent
the instrument from stalling during work.
 Micro motor fall into two categories;
 Air driven- cheaper and robust
 Electric driven- versatile but expensive.
81

81. DENTAL HANDPIECES
• Air rotor
• 2 patterns are in common use
• Rotary –vane type
• swash-plate type
• Rotary vane drive air motor
 Runs smoothly and can develop considerable
torque
Torque dependent on length and diameter of
motor and pressure of air drive.
Can be easily autoclaved.
82

82. DENTAL HANDPIECES
• Swash-plate drive air
motor
• It can not work in high
speeds
• Loosing popularity when
compared with the
rotary vane air motor.
83

83. ELECTRIC MICRO-MOTOR
• These are DC motors and are
designed with an armature
sitting within a permanent
assembly. The performance on
• Design and power of field
magnet
• Design and number of
armature coils
84

84. COUPLINGS…
 A number of couplings are available to connect the air-turbine and
micro-motor to the hoses of the instrument delivery units.
 Handpiece is attached to the motor by means of an E- coupling
which is a snap –on alignment of parts.
 Coolant spray connecting system may be internal or external. Their
purpose is to deliver air and water in the form of an aerosol.
85

85. COUPLINGS…
What Are the Types of Tubing Connections?
2 Hole (Borden Connection)
• Usually the standard in developing countries (e.g., all of Latin America).
• Has one large hole, which is air intake to drive the turbine to spin, and a small hole
for water to cool the bur/tooth.
• No air exhaust, so the exhaust just blows right out of the handpiece, making it
much louder.
• Also, no chip air, so the water comes out more as a stream than as a fine mist.
• A 2/4 adapter can be used to fit this kind of handpiece onto 4 hole tubing, but the
handpiece will still not have the chip air or exhaust air features.
86

86. COUPLINGS…
3 Hole
• Used very little.
• Has the same handpiece thread design as 2 hole, but with the addition of
one extra small tube for the chip air line to allow the water to come out as
a fine mist.
• Can be converted to 2 hole by simply removing the chip air tube.
87

87. COUPLINGS…
4 Hole (Midwest Connection)
• The standard in the U.S. and Europe.
• Has two large air holes (the smaller of the two is air in and the larger is air
exhaust out).
• Also has two small holes, a water tube and a chip air tube (which brings air
to the head where it either mixes with or hits the water to make a fine mist)
to cool the bur/tooth and clear debris.
• A 4/2 adapter can be used to fit this kind of handpiece onto 2 hole tubing,
but the handpiece will lose the exhaust and chip air feature.
88

88. COUPLINGS…
5 Hole
• Has the same handpiece thread design as 4 hole, but with the addition of a
fiber optic rod which transmits light through the handpiece and illuminates
the bur and tooth area for better visibility.
• Has all the other features of 4 hole as well.
•A 5 hole handpiece can be used on 4 hole tubing, but the light feature will
not function.
89

89. CHUCKING MECHANISMS
 Chucking Mechanism-The mechanism that allows the
handpiece to hold a bur.
Types:
1. Standard Screw-Type (bur tool-type)
• The spindle and chuck (the parts of the turbine that
hold the bur) are separate.
• A bur tool is required to insert and remove the bur; it
screws the chuck down into the spindle causing the
chuck to tighten around the bur.
• Screw-type chucks can be replaced and repaired.
90

90. CHUCKING MECHANISMS
2. Push Button-Type
• The spindle and chuck are a single assembly.
• The push button cap on the handpiece
presses on the actuator on the top of the
spindle which engages an internal spring
component to open or close the chucking
mechanism.
• Bur shank size is important – burs with shanks
under .0626 inch. or over .0630 inch. cannot
be used.
91

91. CHUCKING MECHANISMS
Benefits of Push Button Chucks
• Easy insertion and removal of burs.
Disadvantages of Push Button Chucks
• Do not provide as strong a grip on the bur as screw-type chucks.
• Heavy use can cause the chuck to strip, which will result in poor bur retention.
• Higher cost to purchase.
• Once the chuck fails the whole turbine must be replaced instead of just the chuck.
92

92. COLOR CODING OF HAND PIECES:
 These indicate the relative gear ratio of each
component and are present in the form of
dots or rings.
 Blue- no change in speed
 Green- speed reduction
 Red- speed increase
93

93. RECENT ADVANCES..
1.Fibre optic handpieces:
a. provide light at working site.
b. Shut-off delay –Allows illumination even after release of foot control
2.Cellular optic handpieces:
handpiece can be repeatedly sterilized without light degradation.
3.Lube free ceramic bearing handpiece:
a. Do not require lubrication
b . Care should be taken against chemicals
94

94. RECENT ADVANCES..
95
Fibre optic Cellular optic Lube free ceramic bearing

95. STERILISATION OF HAND PIECES
1. with metal bearing: a. Scrub the metal bearing with water and soap
b.Lubricate and place in sterilisation bag and
autoclave
2. Lube free ceramic bearing: Must not be chemically sterilized- damage to internal
parts.
3.Chemical vapour pressure sterilisation.
4.Ethylene Oxide gas :
a.provide both internal and external sterilization due to penetrating capacity.
b.Takes long time for sterilization
Dry heat for handpiece sterilization is not recommended.
96

96. STERILISATION OF HAND PIECES
97

97.  Dental procedure in which the deposition of oil
spray onto tooth structure might interfere with
processes, such as dental adhesion.
 Most handpieces require reoiling after
sterilization, and excess oil may be sprayed during
the start-up operation.
 It is recommended to run the handpiece for a 30
seconds before initiating work.
98

98. To be continued….
99