Chapter 19
Chairside Instruments and
Tray systems.
Structural Parts of Dental Hand
Instruments
• Working End
– The end of the instrument that actually
performs the function.
– Comes in three generalized categories.
• Point
• Blade
• nib
Descriptions of the working end!
• Point:
– sharp tip
used to:
• explore and detect.
– Example: explorer
Description of working end cont.
•
•
•
•
Blade:
flat or curved,
rounded edge or a cutting edge.
beveled or bi-beveled,
– Example:
• Gregg 4/5 (round edge),
• Hollenback carver, (beveled edge).
Description of working end cont.
• Nib:
• a blunt or flat end.
• serrated or smooth.
– Example:
– Amalgam condenser,
– Endodontic plugger.
Classification of Dental
Instruments
• Instruments are classified by:
–
–
–
–
Number of working ends.
Function.
Manufactures name.
Black’s number formula.
Number of working ends
• Single-ended:
– one working end
– generally a longer
handle.
– single function
– multi-function
• Double-ended:
–
–
–
–
–
–
ends are same,
opposite directions
different functions
different sizes
paired left and right
mesial or distal
Instruments classified by function
• CUTTING:
– used to design (shape or form)
the cavity prep,
– define and refine walls / floor of the prep.
– Cuts enamel and dentin.
The six cutting hand instruments
• 1. Chisels: shapes the walls,
– pushing motion.
• 2. Hatchets: refine walls / retention,
– paired left and right.
• 3. Hoes: smooth and shape the floor
– pulling motion.
• 4. Angle formers: defines point angles.
– corners of the prep. downward pushing motion.
Chisel Hatchet
Hoe Angle
former
Cutting instruments cont.
• 5. Gingival margin trimmer (GMT)
– double ended instrument
– comes paired mesial and distal.
– Are used to bevel (slant or angle) the gingival
margin of the cavity prep.
– cuts enamel. It does not trim the gums.
GMT distal
GMT mesial
Cutting instruments cont.
• 6. Excavator, AKA
Spoon excavator
– scoop and remove
caries and debris from
the prep/tooth.
– Double ended
– Used when there is a
risk of perforating into
the pulp chamber with
the handpiece and bur.
Non-cutting hand instruments.
• Includes the basic set-up.
– Mouth mirror
– Explorer
– Cotton pliers
• AKA cotton forceps or pick-ups.
• This is a guideline for a basic set-up. Your
dentist will determine which instruments
they would like in their basic set-up.
Examples of
Non-cutting instruments cont.
• Periodontal probe
• Spatula
• Amalgam carrier
• Articulating paper
forceps
• Gregg 4/5 aka “plastic
instrument”
• Scissors: (they don’t
cut tooth structure)
• Amalgam condenser
• Burnisher
Carving instruments.
• Carvers are used to carve amalgam not
tooth structure!
The three main carver are listed next. There
are others. The ones you have in your
office will depend on the doctor.
Carving instruments cont.
• T-3 carver:
• carves amalgam occlusal and interproximal
• Hollenback carver:
• carves amalgam interproximal.
• Cleoid-Discoid carver: aka (C-D)
• carves amalgam occlusal.
• All can be used to carve anatomy (pits and
fissures) into the occlusal surface.
Cleoiddiscoid
Hollenback T-3
Dental Rotary Instruments
• Burs, aka rotary
instruments!
–
–
–
–
–
discs,
stones,
rubber polishers,
mandrels,
lab burs.
• Used for
– cavity preparation,
– finishing and polishing
restorations,
– surgical procedures
– adjusting appliance.
Parts of the bur!
• Shank:
– the part of the bur you
place in the chuck of
the handpiece.
• Straight shank:
– are longer, larger
shanks
– associated with lab
burs.
• Latch-type shank:
– has a notch
– contra-angle
attachment
– slow-speed handpiece
• Friction-grip shank:
– smooth on the end
– high-speed handpiece
Parts of the bur cont.
• Head:
– is the working end of
the bur. It performs
the function.
– different shapes
– different sizes
– different # of blades
• Neck:
– is the tapered part of
the bur that connects
the shank to the head
of the bur.
Cutting Burs
• Round: FG or latch, opens the tooth and
removes caries. Sized 1/4 - 10
• Inverted cone: FG or
latch, removes caries
and place retention
grooves / undercuts.
Sized 331/2 - 37 or
37L (long)
Cutting burs cont.
• Straight fissure:
• Sized 56 - 58L
• Tapered fissure:
• Sized 169 - 171L
• Cross-cut straight
fissure:
• Sized 556 -558L
• Cross-cut tapered
fissure:
• Sized 699 - 701
Straight
fissure
Cross-cut
straight fissure
Tapered
fissure
Cross-cut
tapered fissure
Cutting Burs cont.
• End cutting:
– form the shoulders of
crown preps.
• Wheel:
– used to form retention
in the prep.
• Pear:
– used to open and
extend the prep. Sized
329-331L.
• Diamond burs:
– rapid reduction of tooth
structure.
– polishing and finishing
– occlusal adjustments.
– Identified by grit:
• (fine, med., coarse)
– Many different shapes
and sizes.
Diamond burs.
Additional Burs
• Finishing burs:
– smooth, trim, and
finish restorative
material.
– increased # of blades
– different shapes and
sizes,
– gold colored shank
• Surgical burs:
– FG or latch grip,
– reduce, remove, or
reshape the bone and to
section (cut) a tooth
into pieces.
– Come in many shapes
and sizes, (same as the
cutting burs), shaft of
the bur is longer
Additional burs cont.
Additional burs cont.
• Stones: used for
cutting, polishing and
finishing restorations
and appliances.
– Many different shapes
and sizes.
– Common stones used,
white and green stones.
(darker the color the
more abrasive the
material.)
• Rubber points or cups:
aka greenies, and
brownies.
– FG or latch.
– polish metals and
define anatomy in
restorations.
– polishing amalgam and
gold
Additional burs cont.
Additional burs cont.
• Lab bur: AKA acrylic
bur or a vulcanite bur.
• Mandrel: designed to
hold polishing disks.
– Used to adjust
appliances, extraorally.
– slow speed motor and
nosecone,
– used in a lathe in the
dental lab.
– Many different shapes
and sizes.
– used to smooth, polish
and adjust composite.
– different grits,
– discs are made of:
– metal,
– plastic,
– paper.
Additional burs cont.
Bur Blocks
• Bur blocks
– hold, separate, and
organize burs.
– set up by bur, doctor,
or procedure.
– magnetic
– different shapes and
sizes,
– autoclaveable.
•
Handpieces
• Parts of the handpiece
– Working end: where
the bur is placed
– Shank: the part of the
handpiece you hold
onto. AKA the handle.
– Connection end: the
end that attaches to the
power source or line.
•
High speed handpiece
• Spins at 400,000 rpm
• rapid cutting of tooth
structure
• finishing restorations.
• Produces frictional
heat
– pulpal damage.
– Spray water.
• No attachments
– just burs.
• Speed is controlled by
the rheostat.
• Fiber optic light
source
• Do not place in
ultrasonic!
Slow-speed handpiece
• AKA low-speed, or
•
straight handpiece.
• Rotates about 30,000
rpm.
• Used with a contraangle or pro/right
angle attachment.
• No water, but can and
does produce frictional
heat.
Instrument tray systems
• Pre-set trays: very common, saves time.
• Instruments should be set according to the
order they will be used. This may vary
from doctor to doctor.
• Color-coding: may be used to identify:
– Which procedure they are for.
– Which operatory they belong in.
– Which doctor they belong to.
Instrument tray systems
Closing
• Knowing and understanding dental
instruments is a very important part of your
job.
• This is a foundation for you to build you
instrument knowledge.
• Any question?