Fundamentals of “Universal” Instruments:

Fundamentals of “Universal” Instruments:

Deborah l. Cartee, RDH, MS

Homework

Reading Assignments:      Wilkins Chapter 38

Darby Chapter 26

Objectives1. 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

A = HandleB = ShankC = Working-end

Single ended

Single ended

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.

Double Ended Design

Handle Diameters

Handle Texturesmooth

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 ata 90 degree angle tothe 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

(retraction, mirror)

(light, bracket tray)

(sickle)

(stool position)

(supine, chin & head position)

(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

The above shows a straight shankedsickle. Since we will not use this type of instrument, please focus instead on the Terminal Shank and its cuttingedges and how it relates to the tooth.

Initial point of insertion is always at the line angle

Mandibular Anteriors: BuccalRight Handed Clinician

1. From a 11:30 position, insert at the Distal Buccal Line Angle of #22 (tip towards the col)2. Initiate walking stroke towards and into the distal col. Remove at end of pull stroke3. Reinsert at the Mesial Buccal Line Angle of #22 (tip towards the mesial col) 4. Initiate walking stroke toward and into the mesial col. Remove at end of pull stroke5. Move onto #23 D and then #23 M, then #24D, #24 M, etc.

#22#23#24#25#26#27

123456

Mandibular Anteriors: Lingual Right Handed Clinician

1. From a 11:30 position, insert at the Distal Lingual Line Angle of #22 (tip towards the col)2. Initiate walking stroke towards and into the distal col. Remove at end of pull stroke3. Reinsert at the Mesial Lingual Line Angle of #22 (tip towards the mesial col) 4. Initiate walking stroke toward and into the mesial col. Remove at end of pull stroke5. Move onto #23 D and then #23 M, then #24D, #24 M, etc.

#22 #23 #24 #25 #26 #27

Mandibular Anteriors: BuccalLeft Handed Clinician

1. From a 12:30 position, insert at the Distal Buccal Line Angle of #27 (tip towards the col)2. Initiate walking stroke towards and into the distal col. Remove instrument at upward stroke3. Reinsert at the Mesial Buccal Line Angle of #27 (tip towards the mesial col) 4. Initiate walking stroke toward and into the mesial col. Remove instrument at upward stroke5. Move onto #26 D and then #26 M, then #25D, #25 M, etc.

#22#23#24#25#26#27

123456

Mandibular Anteriors: Lingual Left Handed Clinician

1. From a 12:30 position, insert at the Distal Lingual Line Angle of #27 (tip towards the col)2. Initiate walking stroke towards and into the distal col. Remove at end of pull stroke3. Reinsert at the Mesial Lingual Line Angle of #27 (tip towards the mesial col) 4. Initiate walking stroke toward and into the mesial col. Remove at end of pull stroke5. Move onto #26 D and then #26 M, then #25D, #25 M, etc.

#22 #23 #24 #25 #26 #27

Stroke Sequence for Posterior Teeth:

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 angle-proceed with walking stroke into the mesial col area.

1 1 1 12 2 2 2

Correct working end:

Terminal Shank

Auxiliary Shank

Incorrect working end:

Terminal Shank

Auxiliary Shank

Correct!

Working End

Incorrect

Correct!

Working End

Incorrect

Angulation

Correct Angulation- 70°to 80°

Burnished Calculus –< than 70°

Angle >90°Angle <45°

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 directbuccal/lingualsurfaces!!!

Walking Sequence (per quadrant):

(limited radius)

For Right Handed Clinicians:

Midline

Notice that operator position and the direction of the instrument handle changes at the canine on the dominant side.

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Walking Sequence(per quadrant):

(limited radius)

For Left Handed Clinicians:

Notice that operator position and the direction of the instrument handle changes at the canine on the dominant side.

Midline

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Summary

You will be using the Posterior Sickle on

ALL proximal surfaces in the mouth.

When you are scaling only the anterior teeth- please 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