Fundamentals of
“Universal” Instruments:
Deborah l. Cartee, RDH, MS
Homework
Reading Assignments:
Wilkins Chapter 38
Darby Chapter 26
Objectives
1. Describe and identify the general characteristics of
dental instruments.
2. Discuss variations in instrument shank length,
curvature, flexibility, and blade-to-shank
angulation.
3. Identify a given instrument by its classification,
design, number and manufacturer’s name
4. Select the appropriate instrument for a given task.
5. Discuss proper instrument blade adaptation and
angulation.
6. Compare and contrast the metals used in
instrument construction.
7. Compare scalers and curettes.
Objectives Cont.
8. Compare universal and area specific curet.
9. Describe the distinct characteristics of a scaler.
10. Describe the distinct characteristics of a curet.
11. Determine and descrbe the correct cutting edge for
each instrument in the cassette.
12. Demonstrate proper adaptation, insertion,
angulation, and activation of each instrument in
the cassette.
13. Evaluate successful instrumentation.
Instrument Parts
 Handle
 Shank
– Shape (straight or angled)
– Flexibility
– Lower or terminal shank
 Working End- Blade
Handle, Shank, Blade
Materials Used for Blade
 Stainless Steel
– Metal
– Maintains adequate sharpness
– Do not rust or discolor
 Carbon Steel
– Metal
– Feel sharper clinically and hold their sharpened edges longer
– More brittle, can break more easily than SS
– Tends to oxidize or rust
 *Gold “tipped”
– Metal
– Expensive
– Used for Implants
 *Teflon
– Plastic/Graphite reinforced nylon
– Only used for Implants
*See Darby page 1032-1035
Implant – Teflon Instruments
Instrument Handle




Overall design – single ended vs. double ended
Weight
Diameter
Surface texture
– Serrations
Parts of an Instrument
Single ended
Single ended
A = Handle
B = Shank
C = Working-end
Double Ended Design
Top instrument (Unpaired) is an example of a
curet (on the left) and an anterior sickle on the (right)
Bottom instrument (Paired) is an example of a
posterior sickle on both ends.
Handle Diameters
Handle Texture
smooth
knurled
ribbed
knurled
Working End
2 Types of Universal Instruments:
2 Types of Universal Instruments:
1. Scalers-
(in cross-section)
pointed tip
pointed back
supragingival calculus removal
2. Curets -
(in cross-section)
rounded tip
rounded back
sub/supragingival calculus removal
Face
Face
To date you’ve learned:
*#17 Explorer
* ODU Explorer
Let’s first talk about the
Sickle Scalers
Types of Sickle Scalers:
 Anterior- ‘straight’ shank
instrument
 Posterior- ‘curved’ or multiple
shank instrument
– (actually can be used universally in the mouth)
Terminal shank is at
a 90 degree angle to
the Face
Anterior Sickle
Straight Shank
Design Characteristics:
Basically there are 2 cutting edges at each end.
The Face of the Sickle Scaler is at a 90 degree angle to the terminal shank.
Flat “face”
Terminal shank
Note:
You do NOT have an anterior sickle scaler in
your cassette.
You have a “posterior” sickle scaler – 204S
(S204S7).
We will use this instrument in the anterior and
the posterior (universal).
We will use this instrument on proximal
(mesial and distal) surfaces only. We will
NEVER use it on facial and lingual surfaces.
Sickle scalers have a pointed tip and two cutting
edges on each end of the instrument:
Let’s get prepared to
scale with the
Sickle Scaler – 204S
Must maintain side of tip!
Correct!
Incorrect
P. 210
(stool position)
(supine, chin & head position)
(light, bracket tray)
(retraction, mirror)
(sickle)
(fulcrum)
Keep In Mind:







Operator and Client Positioning
Instrument Blade Selection
Grasp
Fulcrum (Max. palm up, Mand. palm down)
Insertion at 0°
Adaptation open to 70°to 80°
Angulation- maintain side of tip
Please remember:
The Sickle instrument is used
SUPRAGINGIVAL!
(You can go sub about 1-2 mm if necessary, but not more than that!!!)
The Sickle instrument will be used
Mesial & Distal!
(You can NOT use on facial and lingual surfaces!!! )
Start at the Line-angle
Anterior Scaler
Initial point of insertion is always at
the line angle
The above shows a straight shanked
sickle.
Since we will not use this type of
instrument, please focus instead on
the Terminal Shank and its cutting
edges and how it relates to the tooth.
Mandibular Anteriors: Buccal
Right Handed Clinician
5
6
#27
1.
2.
3.
4.
5.
#26
4
#25
3
#24
2
#23
1
#22
From a 11:30 position, insert at the Distal Buccal Line Angle of #22 (tip towards the col)
Initiate walking stroke towards and into the distal col. Remove at end of pull stroke
Reinsert at the Mesial Buccal Line Angle of #22 (tip towards the mesial col)
Initiate walking stroke toward and into the mesial col. Remove at end of pull stroke
Move onto #23 D and then #23 M, then #24D, #24 M, etc.
Mandibular Anteriors: Lingual
Right Handed Clinician
#22
1.
2.
3.
4.
5.
#23
#24
#25
#26
#27
From a 11:30 position, insert at the Distal Lingual Line Angle of #22 (tip towards the col)
Initiate walking stroke towards and into the distal col. Remove at end of pull stroke
Reinsert at the Mesial Lingual Line Angle of #22 (tip towards the mesial col)
Initiate walking stroke toward and into the mesial col. Remove at end of pull stroke
Move onto #23 D and then #23 M, then #24D, #24 M, etc.
Mandibular Anteriors: Buccal
Left Handed Clinician
5
6
#27
1.
2.
3.
4.
5.
#26
4
#25
3
#24
2
#23
1
#22
From a 12:30 position, insert at the Distal Buccal Line Angle of #27 (tip towards the col)
Initiate walking stroke towards and into the distal col. Remove instrument at upward stroke
Reinsert at the Mesial Buccal Line Angle of #27 (tip towards the mesial col)
Initiate walking stroke toward and into the mesial col. Remove instrument at upward stroke
Move onto #26 D and then #26 M, then #25D, #25 M, etc.
Mandibular Anteriors: Lingual
Left Handed Clinician
#22
1.
2.
3.
4.
5.
#23
#24
#25
#26
#27
From a 12:30 position, insert at the Distal Lingual Line Angle of #27 (tip towards the col)
Initiate walking stroke towards and into the distal col. Remove at end of pull stroke
Reinsert at the Mesial Lingual Line Angle of #27 (tip towards the mesial col)
Initiate walking stroke toward and into the mesial col. Remove at end of pull stroke
Move onto #26 D and then #26 M, then #25D, #25 M, etc.
Stroke Sequence for Posterior Teeth:
2
1
2
1
2 1
2 1
2
Notice that you will begin your working stroke at the
Distal Line Angle (1) and proceed into the distal col.
You will then reinsert tip at the Mesial Line Angle (2)
(tip now pointing towards the Mesial). Remember,
Terminal shank of instrument is parallel to the line angleproceed with walking stroke into the mesial col area.
Auxiliary Shank
Terminal Shank
Correct working end:
Incorrect working end:
Auxiliary Shank
Terminal Shank
Working End
Correct!
Incorrect
Working End
Correct!
Incorrect
Angulation
Correct Angulation- 70°to 80°
Burnished Calculus –
< than 70°
Angle <45°
Angle >90°
Incorrect angulation- 90°
Why is this a problem?
Start at the distal
line-angle with the
tip facing distally.
Do Not use the
sickle on direct
buccal/lingual
surfaces!!!
Walking Sequence
(per quadrant):
Midline
(limited radius)
1.
2.
For Right
1.
Handed Clinicians:
2.
2.
1.
2.
2.
2.
2.
2.
2.
2.
2.
2.
Notice that operator position and the direction of the instrument
handle changes at the canine on the dominant side.
1.
2.
1.
1.
2.
2.
1.
1.
2.
1.
2.
1.
2.
2.
Walking Sequence
(per quadrant):
Midline
(limited radius)
1.
2.
2.
For Left
2.
Handed Clinicians:
2.
2.
2.
2.
1.
2.
2.
1.
2.
1.
2.
Notice that operator position and the direction of the
instrument handle changes at the canine on the dominant side.
2.
2.
1.
1.
2.
1.
2.
2.
1.
1.
2.
1.
2.
1.
Summary
You will be using the Posterior Sickle on
ALL
proximal surfaces in the mouth.
When you are scaling only the anterior teethplease follow the sequence in slides (slides #44-45)
When scaling posterior and anterior teeth in a
single session- instrumentation sequence is:
quadrant at a time! (slides #44-45)
In Review You Should
ALWAYS Keep in Mind:





Lateral Pressure
Strokes
Stroke Direction
Stroke Length
Reinforcement
Now, Let’s take a look at the
Universal Curet
 The Universal curet is similar to the Sickle in
that it also has two cutting edges per end.
 The difference between them is that the tip
of the Universal curet is rounded- not
pointed like the Sickle.
 This allows you to use this instrument
SUBGINGIVAL!!!
Universal Curets:
Scalers
-
(in cross-section)
pointed tip
pointed back
supragingival calculus removal
Curets -
(in cross-section)
rounded tip
rounded back
sub & supragingival calculus removal
Universal Curets
 Columbia 13/14 (SC13/147)
 Barnhardt
 Younger Good
 Blade size, shank length and design will determine
preferred area usage.
So, Let’s Keep in Mind. . .
 Fulcrum rest must be near, but not directly over
the surface being scaled (fulcrum on same arch).
 Determine correct working end of instrument:
 Terminal shank parallel to MESIAL line angle of molar
 Foot of instrument curves towards the tooth
 Angle for insertion is 0-40 (closed blade)
Oblique Stroke
Continued. . . .
 With closed blade, insert subgingival to JE- lateral
pressure should be fairly light.
 Open angle to 45-90° (subgingival) and initiate
exploratory stroke (pull stroke)
 Lateral pressure against tooth should remain fairly light unless a
‘bump’ is felt. Return back to JE and apply firmer pressure
during pull stroke to remove ‘bump’  calculus?
 Fulcrum pressure increases during pull stroke
Continued. . .
 Relax fingers during exploratory stroke
 Apply greater lateral pressure during pull stroke.
 Strokes should be short and controlled, with
moderate pressure from the base of the pocket,
toward the gingival margin.
 Stroke direction – vertical, oblique & horizontal
(overlapping) remaining primarily in the gingival
sulcus.
Please remember…
 You should ALWAYS scale a tooth to
completion!!!
 That means: Look at the clock and budget your
time!!!
 How long will it take you to scale a lingual/buccal
surface?
 Dependent on : How ‘heavy’ the calculus is
How ‘tenacious’ the calculus is
How good is your technique?
 Then determine how many teeth you can scale
thoroughly and completely with the amount of time
you have. . .
Cutting Edges
Adaptation
Incorrect 90°Angulation