Copyright © 2008 Wolters Kluwer Health | Lippincott Williams & Wilkins Dental Mirror.

Copyright © 2008 Wolters Kluwer Health | Lippincott Williams & Wilkins

Dental Mirror


Dental Mirror

• The working-end of a dental mirror has a reflecting mirrored surface.


Types of Dental Mirrors


Three Common Types

1. Front Surface

2. Concave

3. Plane (Flat) Surface


Front Surface

• Produces a clear mirror image with no distortion

• Most commonly used type because of good image quality


Concave

• Produces a magnified image

• Not recommended because magnification distorts the image


Plane (Flat) Surface

• Produces a double image (ghost image)

• Durable, resists scratching because the reflecting surface is on the back of the mirror lens

• Not recommended because double image is distracting


Uses of Dental Mirror



1. Indirect Vision

2. Retraction

3. Indirect Illumination

4. Transillumination


1. Indirect Vision

• The use of a mirror to view a tooth surface or intraoral structure that cannot be seen directly


• Use of the mirror to hold the patient’s cheek, lip, or tongue so that the clinician can view tooth surfaces that are otherwise hidden from view by these soft tissue structures

2. Retraction


Retraction of Tongue


Retraction of Lip• The index finger is

used to retract the lip away from the teeth

• More comfortable for patient than using a mirror for retraction of the upper or lower lip


Retraction of Cheek


3. Indirect Illumination• Use of the mirror to

reflect light onto a tooth or soft tissue structure in a dark area of the mouth



• The technique of directing light off of the mirror surface and through the anterior teeth



• The dental mirror has four important functions during periodontal instrumentation:

1. Indirect Vision

2. Retraction

3. Indirect Illumination



Characteristics of Periodontal Instruments


Topics

• Paired and unpaired instruments• Instrument identification• Working-end identification• Instrument handles• Instrument balance


Paired and Unpaired Instruments


Paired and Unpaired

• Unpaired working-ends: instrument with two dissimilar working-ends

• Paired working-ends: instrument with working-ends that are mirror images of each other


Unpaired vs. Paired


Instrument Identification


Design Name

• Design Name: school or person who designed instrument (for example: Gracey)


Design Number

• Design Number: identifies the working-ends (example: 1 and 2)


Working-End Identification


Number Along Handle

• Each working-end is identified by the number closest to it.


Number Across Handle

• The first number (on the left) identifies the working-end at the top.

• The second number is the working-end on the lower end of the handle.


Instrument Handles


Examples of Handle Designs


Choosing the Right Handle

RECOMMENDED• Large diameter• Lightweight handle• Bumpy texturing

AVOID• Small diameter• Heavy, solid metal

handle• Smooth or flat

texturing


Instrument Balance


• A periodontal instrument is balanced if the working-ends are aligned with the long axis of the handle.


Balanced?

• Balanced if the working-ends are centered with the midline of the handle

• A = Not balanced• B = Balanced


Significance of Balance

• Ensures that finger pressure applied against the handle is transferred to the working-end for calculus removal

• An instrument that is not balanced is difficult to use and stresses the muscles of the hand.


Summary: Recognize Design Features

• Paired or unpaired working-ends• Instrument identification• Working-end identification• Handle design• Instrument Balance



Shank Design


Topics

• Simple and complex shank designs• Functional and lower shank portions• The best instrument for a task• Specialized instruments with extended lower

shanks


Shank Bends

• The shanks of most periodontal instruments are bent in one or more places to facilitate placement of the working-end against the tooth surface.


Simple Shank Design

• Hold the instrument so that the working-end tip or toe is facing you

• Simple shank will appear to be straight


Complex Shank Design

• Hold the instrument so that the working-end tip or toe is facing you

• Complex shank has side-to-side bends


Comparison of Shank Designs

• Simple shanks: for use on anterior teeth

• Complex shanks: for use on posterior teeth


Selecting the Right Shank for the Task

• Should I select an instrument with a simple shank design or a complex shank design?


Simple Shank: Anterior Tooth

• Anterior teeth are wedge-shaped.

• A simple shank is adequate to reach along the crown and onto the root.


Posteriors: Complex Shank

• Posterior teeth have large, bulky crowns that are larger in diameter than the roots.

• A complex shank is needed for posterior teeth.


Complex Shank: Facial and Lingual

• The illustration shows a molar when viewed from the mesial aspect.

• Front-to-back shank bends allow you to reach the facial and lingual surfaces of the root.


Complex for Proximal Surfaces

• The illustration shows a molar when viewed from the facial aspect.

• Side-to-side bends allow you to reach the mesial and distal surfaces of the root.


Regions of the Shank


Functional and Lower Portions

• Functional shank: the portion of the shank that allows the working-end to be adapted to the tooth surface

• Lower shank: the portion of the functional shank that is nearest to the working-end; also called the “terminal” shank


Functional Shank

• Begins below the working-end, and extends to the last bend in the shank nearest the handle


Lower Shank

• The portion of the functional shank nearest to the working-end


Selecting the Best Instrument for a Task


Instrument Use: Simple Shank

• Simple shank with short functional shank length—supragingival use on anterior teeth

• Simple shank with long functional shank length—subgingival use on anterior teeth


Complex Shank Use

• Complex shank with short functional shank length—supragingival use on posterior teeth

• Complex shank with long functional shank length—subgingival use on posterior teeth


Specialized Instruments with Extended Lower Shanks


Extended Lower Shanks

• Instrument A has a standard lower shank.

• Instrument B has an extended lower shank.


Use: Extended Lower Shank

• Instruments with extended lower shanks can reach the middle- and apical-third of the root surface.


Important Shank Characteristics

• Determine if shank is simple or complex

• Recognize the functional shank

• Recognize the lower shank

• Recognize an extended lower shank


Working-End Design


Topics

• Parts of the working-end

• Working-end in cross section

• Introduction to Instrument Classification


Working-End Design

• An instrument’s function is determined, primarily, by the design of it’s working-end.

• To determine an instrument’s use, you must recognize the design characteristics of the working-end


Overview: Parts of Working-End

• Face

• Back

• Lateral surfaces

• Cutting edges

• Toe or tip


Face and Back

• The shaded surface on this illustration is the face.

• The surface opposite the face is the back of the working-end.


Lateral Surfaces

• The surfaces on either side of the face are called the lateral surfaces of the working-end.


Cutting Edge

• The cutting edge is a sharp edge formed where the face and lateral surfaces meet.

• Most working-ends have 2 cutting edges.


Toe

• This is a bird-eye view, looking down on the face.

• On some working-ends the cutting-edges meet to form a rounded toe.


Tip

• This is a bird-eye view, looking down on the face.

• On some working-ends the cutting-edges meet to form a pointed tip.


The Working-End in Cross Section


• The cross section of a working-end is exposed by cutting through the working-end at right angles to its longest dimension.


Significance of Cross Section

• The cross section of a working-end determines whether the instrument can be used subgingivally—beneath the gingival margin—or is restricted to supragingival use.


Instrument Use

• Working-ends that are triangular in cross section are limited to supragingival use.

• Working-ends that are semi-circular in cross section may be used supragingivally and subgingivally.


Creating a Cross Section

• Saw a pencil into two parts by cutting it in the middle perpendicular to the long axis of the pencil.


Hexagonal Cross Section

• The pencil is hexagonal in cross section.

• A hexagon is a six-sided figure.


Working-End Cross Section

• Imagine cutting the working-ends of these instruments in half to reveal the cross section.


Shape of Cross Section

• One working-end is semi-circular in cross section

• The other is triangular in cross section


Triangular Cross Sections

• Sickle scalers are instruments with triangular cross sections.

• Sickle scalers are limited to supragingival use.


Semi-Circular Cross Section

• Curets are instruments that are semi-circular in cross section.

• Curets may be used supragingivally and subgingivally.


Introduction to Instrument Classification


• Periodontal instruments are divided into types, or classifications, based on the specific design characteristics of the working-ends.



Periodontal Probe

• A slender instrument used to evaluate the health of the periodontal tissues

• Blunt, rod-shaped working-ends


Explorer

• Used to locate calculus deposits, tooth irregularities, carious lesions

• Circular in cross section


Sickle Scaler

• Used to remove supragingival calculus deposits

• Triangular in cross section

• Pointed tip• Pointed back


Curet

• Used to remove calculus deposits

• Semi-circular cross section

• Rounded toe• Rounded back


Periodontal File

• Used to crush large calculus deposits

• Each working-end has several cutting edges


Skill Application

• Practice identifying the parts of the working-end and shank.

• Use various colors of nail polish to paint and identify the following on several instruments:

• Face and lateral surfaces of working-end• Functional and lower shanks


Summary

• An instrument’s function is determined, primarily, by the design of it’s working-end.

• To determine an instrument’s use, you must recognize the design characteristics of the working-end.

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Copyright © 2008 Wolters Kluwer Health | Lippincott Williams & Wilkins Dental Mirror.

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