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
 1st
number—indicates width of the
blade or primary cutting edge in tenths
of a millimeter (0.1) e.g. 10=1mm

11.  2nd
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.  3rd
number (second number of a three-number code)—
indicates blade length in millimeters e.g. 8=8mm
 4th
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