Armamentarium 1

Armamentarium-operative dentistry

1. Armamentarium - I

Dr. Habiba Mumtaz
Lecturer
Department of Operative Dentistry

2. Dental Instruments are used to examine,
clean, cut and restore teeth
Main types are:
Hand-held instruments
Rotary instruments
Auxilliary instruments

4. 1) Hand instruments
Examining the mouth and teeth
Scalers
Cutting teeth and removing caries
Placing and condensing restorative materials
Carving and finishing restorations
miscellaneous

5. Hand instrument design
Most hand instruments are made of
stainless steel or carbon steel (incase
of some cutting instruments) and
Teflon-coated
Some chisels and scalers have
tungsten carbide tips brazed to the
cutting edge. This helps them retain
their sharpness for much longer

6. Majority of the instruments have 3
parts:-
Blade
Shank
Handle

7. For increased effectiveness, the
working surface of the instrument
must meet the surface at an angle
This facilitates in the access to
awkward places where approach is
impossible with a straight instrument
One, two or three bends in the shank
of the instrument may be present to
improve access by off setting the
working tip

Instruments with the working tip in line
with the handle are most easy to use

8. Design of the handle is related to
the purpose of the instrument
Light weight with small diameter
handles used primarily for tactile
and exploratory purposes. E.g.
Probes
Heavier, with larger diameter
handles are designed to transmit
heavy pressure and which will be
held for a longer time. E.g.
scalers

9. Cutting instrument names
Black classified all instruments by name
By 1) function e.g. scaler, excavator
By 2) manner of use e.g. hand condenser
By 3) design of the working end e.g. spoon excavator,
sickle scaler
By 4) shape of the shank e.g. mon-angle, bin-angle,
contra-angle
Combing all together, bin-angle spoon excavator

10. Cutting instrument Formulas
Black also developed a numeric
formula to characterize the dimensions
and angles of the working end
These help in identification and
assistance in cataloging and ordering
Formulas are placed on the handle
using a code of three or four numbers
separated by dashes or spaces e.g.
10-8.5-8-14
1
st
number—indicates width of the
blade or primary cutting edge in tenths
of a millimeter (0.1) e.g. 10=1mm

11. 2
nd
number—(of a four number
code) indicates primary cutting
edge angle…measured from a
line parallel to the long axis of
the instrument handle in
clockwise centigrade
Angle expressed as a percent
of 360 degrees e.g. 85% x 360
degrees = 306 degrees
Instrument is positioned so the
number always exceeds 50
If edge is locally perpendicular
to the blade then this number is
normally omitted, resulting in a
three-number code

12. 3
rd
number (second number of a three-number code)—
indicates blade length in millimeters e.g. 8=8mm
4
th
number—indicates blade angle, relative to the long
axis of the handle in clockwise centigrade, e.g. 14 = 50
degrees
The instrument is positioned so that this number is
always 50 or less
In some instances, an additional number is present
along with the formula number on the handle
It is simply to assist the specific manufacturer in caloging
and ordering

13. Using hand instruments
1) Pen grip
Most frequently used
Middle and ring fingers
used for support
Allows fine controlled
movements with light or
heavy touch

14. 2) Palm grip
Instrument held between
thumb and forefinger
Handle lies across the palm
and clasped by remaining
fingers
Thumb used for support
Greater control than with pen
grip when using on maxillary
teeth, providing heavier force
over a limited range of
movement

15. 3) Finger grip
 Modification of palm grip
Of limited value
Used when palm grip fails to give
correct line of access
REMEMBER !
All instrumentation must be
accompanied by finger or thumb
support upon adjacent firm structures,
commonly, crowns of the adjacent
healthy teeth
Thumb and third or fourth fingers of the
hand holding the instrument most
commonly used for rest
Provides for accuracy in fine
movements, and safety in forceful
manipulations

16. INSTRUMENTS USED FOR EXAMINING THE
MOUTH AND TEETH
1) MOUTH MIRRORS
•Vary in size
•Flat mirrors most commonly preferred and used
•Two main types are:-
A) Front-surface reflecting
•Produce a clearer image particularly at angles
•Most widely used
•Easily scratched
•Care required during cleaning and sterilization

17. B) Rear-surface reflecting
•Reflective surface beneath the glass so image seen through the
thickness of glass twice
•Hence, produces a double image
•However, resistant to damage due to glass surface
•FUNCTIONS
•Retraction of tongue and cheek
•View areas not visible by direct vision
•Reflect operating light to dark areas

18. 2) PROBES
•Mainly used for diagnoses with care taken by the
operator
•Types and functions :-
•A) straight probe (actually bent)
•Checks the margin of restoration
•Examination of caries in dentine during cavity
preperation
•Helpful if sharp
•B) Briault probe
•Sharp probe
•Easy access to enamel-dentine junction during cavity
preparation
•For detection of subgingival calculus

19. •3) periodontal probe
•Blunt with small ball at the end
•Marked with graduations to
measure depth of periodontal
pockets
•May measure the width of a tooth
when a temporary crown is to be
fitted
•Other types are:- CPITN and
FURCATION

20. SCALERS
Used for removing
supra and subgingival
calculus and other
deposits from teeth
Useful for removing
temporary crowns

21. INSTRUMENTS FOR CUTTING TEETH
AND REMOVING CARIES
1) EXCAVATORS
Have discoid or ovoid blade
With margin bevelled to a sharp
cutting edge
Functions:-
For removing soft dentine
Removing temporary fillings
For placing lining with its back
surface (blade)
Sometimes for carving amalgam

22. 2) CHISELS
Straight and angled chisels are used
for splitting off unsupported enamel
Gingival margin trimmer is a double
ended instrument with curved blades
and a sloping cutting edge
Used to trim margins of small cavities
adjacent to other teeth where access
for rotary instruments is limited
3) HATCHETS AND HOES
Similar to chisels in design and
function
Always angled or contra-angled
Hatchets—cutting edge is in the plane
of the shank (like and exe)
Hoe—cutting edge lies in an axis at
right angles to the shank

23. INSTRUMENTS USED FOR PLACING &
CONDENSING RESTORATIVE
MATERIAL
1) PLASTIC INSTRUMENT
Stainless steel material for general use
Teflon coated or titanium nitride for
composite use. Prevents sticking of the
material & not scratched by composite filler
particles
Flat blades—used for conveying and
shaping materials which do not involve the
use of particularly heavy pressure
Round ends—used for pushing materials
into cavities and for shaping and burnishing
Heated for use with certain materials like
wax

24. 2) CONDENSERS OR PLUGGERS
Used for compressing and forming
filling materials, particularly amalgam
Used with heavy pressure
Variety of shapes and sizes available
for use in different situations
End may be smooth or indented
Smooth version preferred as indented
may become clogged with old amalgam

25. 3)CARVING AND FINISHING
INTRUMENTS
Used for carving materials
by cutting or scraping
Have sharp or semi-sharp
blades of various shapes
which is very important
Also important is their
smoothness

26. MAINTAINING HAND INSTRUMENTS
SHARPENING HAND INSTRUMENTS
Instruments will only cut properly if they are
sharp
Steel instruments with bevelled edges, like
chisels, can be sharpened on a small flat
sharpening stone OR on a mounted stone in
a hand piece
Light machine oil used as a lubricant
Instrument held to produce a 30-45 degree
bevel
A fine edge initially cuts better but rapidly
becomes better

27. Alternatively, fine abrasive disc can be
used which are ideal for probes,
excavators and scalers
Light pressure used with no lubricant
Over heating must be avoided
This removes metal rapidly and gives
coarser finish to the edge, but has the
advantage of speed
Tungsten carbide instruments retain
their sharpness for much longer than
steel instruments, but when they
become blunt, they have to be
returned to the manufacturer for
sharpening

28. STERLIZING HAND INSTRUMENTS
Stainless steel, tungsten carbide and Teflon-
coated instruments can be autoclaved
Carbon steel instruments, if autoclaved and left
in a wet condition, will corrode
Hence, it is ideal to autoclave them in a post-
vacuum autoclave
This leaves the contents dry at the end of the
cycle