restorations in pediatric dentistry

7/28/2019 restorations in pediatric dentistry

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Restorations in Pediatric

Dentisty

Dr. Sami Malik Abdulhameed

B.D.S.; M.Sc.


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Objectives of the lecture

To review the ideal dental office setup

To review the moisture control and isolation

To review the restorative materials used in pediatric dentistry To review the Matrices & bands

To review different cavity preparation techniques and some

modifications

To review crown restorations for posterior & anterior teeth


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Restorative Goals

Relief pain & Cease

disease process Restore function

Improve esthetics

Preserve space forpermenant dentition


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Copyright 2003, Elsevier Science (USA). All rights reserved.

Moisture ControlIn

Restorative PediatricDentistry


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Objective: Maintain an environment that keepsthe operating field free of excess water, saliva,blood, tooth fragments, and excess dentalmaterials.

Introduction


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7/250Copyright 2003, Elsevier Science (USA). All rights reserved.

Small, strawlike oral evacuator used duringless invasive dental procedures.

Indications for use:

Preventive procedures such as aprophylaxis or fluoride treatments.

Helps control saliva and moistureaccumulation under the dental dam.

For the cementation of crown or bridge.

During an orthodontic bonding procedure.

Saliva Ejector



Used for most dental procedures, especiallywhen the dental handpiece is in use.

Indications for use

Keep the mouth free of saliva, blood, water,and debris.

Retracts the tongue and cheek away from thefield of operation.

Reduces the bacterial aerosol caused by thehigh-speed handpiece.

HVE



Oral evacuation tips Operative suction tips

Designed with a straight or slight angle inthe middle.

Beveled working end.

Made of durable plastic or stainless steel.

Surgical suction tips

Much smaller in circumference.

Made of stainless steel.

HVE- contd



Thumb-to-nose grasp

Pen grasp

Right hand

Grasping the HVE



Fig. 36-4 Grasping the HVE.



IDEAL ISOLATION


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Objectives of Ideal Isolation Provide optimum visibility and access to

operative site.

Prevent moisture contamination of teeth. Retract and control soft tissue of tongue, lip,

and mucosa.

Protect patient against aspiration of dental

instruments and materials. Provide patient comfort.

Be easily and rapidly accomplished.


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A triangular absorbent pad placed over theStensen's duct blocks the flow of saliva andprotects the tissues in this area.

Dry-Angles


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A thin stretchable latex material becomes abarrier when appropriately applied to selectteeth.

The Dental Dam


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Rubber Dam Application


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Types of Dental Materials

F release material

( Glass Ionomer)Resin Modified Glass

Ionomer

CompositeAmalgam

Stainless Steel


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Fluoride-Releasing MaterialsGlass Inomer & Resin Modified Glass Inomer


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Glass Inomer Cement loses and gains watereasily:

Early moisture contamination leads to increased

solubility and poor esthetics,(protect for first 7 minutes).

Laterdesiccation causes shrinkage and crazing,

(maybe even months later).


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halo effect around restoration ~ 3 mm.

Level around restoration ~ 10 ppm.

Level in saliva of average patient ~ 0.08 ppm.

Fluorine release from GIC does not lead to

restoration breakdown.

GIC - Fluoride Release


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ADA Classification

Type I: luting agents (Ketac-Cem, Fuji I)

Type II: restorative material

a = tooth-colored (Ketac-Fil, Fuji IX)

b = reinforced (Ketac-Silver, Miracle Mix)

Type III:

fast-set liners and bases (Ketac-Bond)

Classification OF GI


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Strengths:

Ionic exchange leads to adhesion to

tooth structure (chemical bond).

Fluoride release and rechargeable.

GIC Physical Properties


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GICPhysical Properties

Weaknesses

Moisture sensitivity.

Lack of command cure, i.e. doesnt curewith light.

Esthetics.

Not recommended for stress-bearing areas. Difficult handling.


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High caries risk patient

Atrumatic Restorative Treatment (ART)

Pediatric dentistry

Class V lesions

Liners & bases & sandwich technique

Luting agents

Core buildups ??? Maybe if > 2/3 of tooth structure remains

Orthopedics (bone substitute material)

GIC Indications


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Steps of Clinical Use of Glass Inomer

1. Mechanical retention in preparation

advised (no bevels).


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2. Dentin conditioning (10

% polyacrylic acid for

10-20 seconds).

3. Inject into preparation.

Overfill the preparation.


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4. Trim excess with finishing bur (wet, with very

light pressure as the cement material cuts

easily!) and polish (if necessary). Be cautious

not to over-reduce, the material is softer than

composite resin.

5. Dry the surface and paint on a thin layer of light-

cured unfilled resin (smoothes the surface and

prevents desiccation but lowers fluoride release.

(optional)


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Glass Ionomers

Advantages

Bond to tooth structure

Physical properties similar

to dentin Moisture tolerant

Release fluoride (5 years)

Fluoride rechargable

Less microleakage


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Glass Ionomers

Disadvantages

Not as strong

Poor wear Increased setting time

Not as esthetic as

composite


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Glass Ionomer Indications

Smooth surface lesions

Small anterior proximal lesions

i.e. areas of low stress

High caries risk patients

Sealants

Base underneath deep carious lesions

Good cement for stainless steel crowns and bracketsand bands

Interim Therapeutic Restorations


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Resin Modified Glass Ionomer

Mixture of glass, an

organic acid, and resin

polymer that harden

when light cured


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Resin Modified Glass Ionomer

Advantages

Increased wear and

fracture toughness

Some fluoride release Comand cure

Increased esthetics

Disadvantages

Not as strong as

composite or amalgam

Less fluoride release thanglass ionomer


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Amalgam

mixture of mercury

(43%-54%) and

powdered alloy

(silver, tin, zinc and

copper)

Once mixed sets

automatically


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Amalgam

Advantages

Quick and easy

manipulation

Less moisture sensitive

Microleakage decreases

with time

Good mechanicalproperties

economical


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Amalgam

Disadvantages

Non bonding

Bulk for strength Proper preparation to

prevent fracture

Wide isthmus

Rounded line angles

Poor esthetics Dental amalgam

controversy


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Composite

Mixture of powdered

glass and plastic resin

Polymerization reaction

initiated by light

Various level of filler

particles can change

esthetics, mechanical

properties, and viscosity


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Composites

Advantages

Micromechanical Bond

Esthetic andpolishable

Conservative

preparation

Preventative Sealants


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Composites

Disadvantages

Moisture sensitive

Technique sensitive Multiple steps

Time consuming

Polymerization

shrinkage leads to

microleakage


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Composite Indications

Small pit and fissure

caries

Class I, II, III, IV andV restorations in

primary and

permanent teeth


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Anterior Strip Crowns

Anterior Restorations

Primary anterior

crown forms


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Stainless Steel

Pre-fabricated

Full coverage

restoration Pre-crimped with 6

sizes

Adapted to tooth


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Stainless Steel

Advantages

Strongest

Preventative

Can be adapted for

space maintainer

Disadvantages

Poor esthetics

Post op discomfort


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Stainless Steel Indications

Pulpotomy

Extensive caries

Fractured teeth Hypoplastic molars


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Stainless Steel Crown Indications

Space Maintainer

Distal Shoe / loop

High caries riskchildren

Patients that require

general anesthetic for

dental treatment


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Stainless Steel Crown

Crown and loop

Placed on tooth that

has extensive decaywith space

maintenance needs


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Anterior Stainless Steel Crowns

Anterior SSC with

windows

Flowable composite Acid etched

Micromechanical and

mechanical retention


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Matrix Systems for

Restorative Dentistry


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Introduction

Amatrix system provides and takes the placeof the proximal tooth surface that was removedto restore the proximal contours and contact totheir normal shape and function.


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Types of Matrices

w Tofflemire

does not fit contour of primary tooth well difficult to fit multiple matrices

W T-band

w Spot welded allows for multiple matrix placement

requires a spot welder chairside

w Automatrix - costly


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Posterior Matrix System

Universal retainerAlso referred to as the Tofflemire retainer.

This device holds the matrix band inposition. The retainer is positioned most

commonly from the buccal surface of thetooth being restored.


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Components of a Universal Retainer

Posterior Matrix System


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Posterior Matrix System-contd

Matrix bands Matrix bands are made of flexible stainless

steel and are available in premolar, molar,and universal sizes and thicknesses.

The largercircumference of the band isthe occlusal edgeand is always placedtoward the occlusal surface.

The smallercircumference of the band is

the gingival edgeand it is always placedtoward the gingiva.


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Fig. 49-2 Types of matrix bands.


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Automatrix System The automatrix system is an alternative to a universal

retainer. There is no retainer used to hold the band in place.

Bands are already formed into a circle and areavailable in assorted sizes in both metal and plastic.

Each band has a coil like autolock loop. A tightening wrench is inserted into the coil and

turned clockwise to tighten the band.

When finished, the tightening wrench is inserted into

the coil and turned counterclockwise to loosen theband.

Removing pliers are used to cut the band.


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Fig. 49-9 Automatrix system.(Courtesy of Dentsply Caulk.)

Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.


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Matrix Systems for Primary


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Matrix Systems for Primary

Teeth The T-band is a T-shaped copper band.

When formed, the top portion of the T allowsthe straight portion to adjust and fit thecircumference of the primary molar.


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Copper T-band used for primary molars.


Additional Matrix Systems for


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Aspot-welded band is a form-fitted bandplaced around a prepared tooth, thenremoved and placed in a smaller form of awelder that fuses the metal together to make

a custom band.

Additional Matrix Systems forPrimary Teeth


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Spot Welded Matrix

w Cut matrix and spot weld

ends

3/16 wide and thin (..002)

matrix

w Form a loop

w Hold ends in spot welderw Weld at low setting


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Fig. 49-8 Spot-welded band.


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Matrices for Composite Restorations

A plastic matrix, also referred to as acelluloid matrix or mylar strip, is used forclass III and IV restorations in which theproximal wall of an anterior tooth is missing.


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A clear matrix system.(Courtesy of Premier Dental Products.)


Th U f Cl M t i


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The Use of a Clear Matrix

The matrix is placed interproximally beforethe etching and priming of a tooth. Thisprotects adjacent teeth from these materials.

After placement of composite material, a

matrix is pulled tightly around the tooth tohelp reconstruct its natural contour.

The clear plastic matrix allows the curing light

to penetrate the material and complete thecuring process.


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Sectional Matrices

A thin polished palodent-type band and atension ring produce a tight anatomic contactfor composite resin materials for class IIrestorations.


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Fig. 49-10 Sectional matrices.


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Sectional matrices.(Courtesy of Garrison Dental Solutions.)

W d


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Wedges

Awedge is either triangular or round andmade of wood or plastic.

The wedge is inserted into the lingualembrasure to position the matrix band firmly

against the gingival margin of thepreparation.


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Fig. 49-6 A wedge correctly positioned.

Restorati e Dentistr for Children


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Restorative Dentistry for Children

BY DR SAMI MALIK ABDULHAMEED.


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Cavity Preparation

Dr. Sami malik abdulhameed


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Objectives

wTo be able to identify and

distinguish morphologicdifferences between primary and

permanent teeth. To apply the

knowledge of morphology inclinical procedures for pediatric

patients

M h l i l C id i i hM h l i l C id i i hM h l i l C id i i h


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Morphological Considerations in the

Primary Dentition

w The crowns of primary

teeth

are shorter have a narrower occlusal

table

have a more pronounced

cervical constriction

have thinner enamel and

dentin layers


Primary Dentition


teeth


table




dentin layers


Primary Dentition


teeth


table




dentin layers


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Primary Dentitionw The crowns of primary teeth

have enamel rods that run in a slightly occlusal

direction from the DEJ have broad flat contact areas between primary

molars

have nearly the same mineral content as

permanent teeth

have a lighter, more homogeneous color


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Contact Area

Point contact

Broad, flat contact



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Primary Dentition

w The pulps of primary teeth are larger than that of the permanent tooth in

relation to crown size

are closer to the outer surface of the tooth the mesial pulp horn is pronounced occlusally

more closely follow the surface of the crown

usually have a pulp horn under each cusp


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Comparison of Pulps


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Influences of Primary Tooth Morphology

w Tooth Preparations

Need to take into account tooth

size, pulp size and enamel anddentin thickness


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Instrumentation

w Utilize a # 245 bur

w Tip -

measure width andlength of cutting shank

w High speed

w Minimal use of hand

instruments


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Cl A l


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Class I Amalgam Preps

w Pulpal Floor Depth -

.5 - 1 mm into dentin primary molars - 1.25 to 1.50mm

w Intercuspal width - 1/3rd

w Rounded internal line anglesw B-L walls slightly undercut

w M-D walls flare at marginal ridges


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Mandibular Molars Outline Form


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Maxillary Molars Outline Form


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Internal Form of a Class I Prep

w 1) depth .5 - 1mm

into dentin

w2) angle of floor andwalls is rounded

w 3) slightly rounded

pulpal floor

Avoids pulp

w 4) sharp cavo-

surface angle


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General Considerations

w Adhere to GV Blacks principles with

respect to outline, resistance, retention andconvenience form and finishing of enamel

walls.


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Class II Cavity Prep - Mandibular


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Class II Cavity Preps - Maxillary


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Class II Amalgam Preps

w Accomplish occlusal outline form

w Extend proximal box into self cleaning area

leave 90 degree cavosurface margins isthmus width 1/3

w Proximal box in an occlusal gingival

direction is parallel to the long axis of thetooth


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Class II, continued

w B-L walls of box should converge

occlusally

w Gingival floor should be beneath thecontact, at, or just beneath the gingival

tissue

w Axial wall should follow the contour of thetooth

1 mm in width


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Cross-sectional View of Class II

w 1a) gingival floor

position 1b) box is

perpendicular to long

axis

w 1c) rounded angles


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Common Errors -Class IIs


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Modifications

w Concave pulpal floor

and gingival seatw Rounded internal line

angles

both decrease stress in

the restorationView from distal surface

of primary 1st molar

B L


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Modifications

w Relatively wider

isthmus width

one-third the

intercuspal distance

w Conservative proximal

extensions

you can see light, butcannot pass an explorer

tip through


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Class 2 slot preparation

Class V Restorations


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Class V Restorations

Aclass Vrestoration is classified as a smoothsurface restoration. These decayed lesionsoccur at:

The gingival third of the facial or lingual

surfaces of any tooth. The root of a tooth, near the

cementoenamel junction.


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Condensation and Carving

w Back to back condensation of Class IIs

w Carving described as hill and valley

w Polishing procedure is same as taught for

permanent teeth


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Condensation and Carving

w Back to back condensation of Class IIs

w Carving described as hill and valley

w Polishing procedure is same as taught for

permanent teeth


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Polishing!


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Failures of Amalgam Restorations

w Fracture of the isthmus of a Class II

due to insufficient bulk of amalgam

w Marginal failure in proximal box area due to excessive flare of the cavosurface

margin

w Recurrent caries failure to extend preparation adequately


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Class III Cavity - Cuspids


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Dovetail is placed on lingual of maxillary cuspids and

the facial of mandibular cuspids.

Proximal box is placed perpendicuar to a line tangent to

the surface on which the dovetail is placed.

Restoration of Proximal-Incisal


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Caries in Primary Anterior Teeth

u Esthetic Resin Restoration

u Stainless Steel Crownu Open-Face Steel Crowns

u Direct Resin Crowns

C i (S i ) C


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Composite (Strip) Crowns


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Preventive

restorationresin

PREVENTIVE RESIN


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PREVENTIVE RESIN

RESTORATION (PRR)

OBJECTIVES:

1. List the indications and contra-indicationsfor PRR for primary and permanent teeth.

2. Describe the PRR materials.

3. Describe the clinical procedures for PRR.4. Identify the advantages of using PRR and

their cost effectiveness.


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The patient presented with infiltration

of the fissures an eroded amalgam

The decayed fissures were opened usingspecial burs, allowing the retention of

healthy tissue to be maximised. The

amalgam restoration was removed.The

dentine was properly cleaned of carioustissue.


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ATRAUMATIC RESTORATIVE

TREATMENT

A.R.T

INTRODUCTION


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INTRODUCTION

Atraumatic restorative treatment (ART) is aprocedure that involves removal of carioussubstance from the tooth using hand instrumentsand restoring with adhesive restorative material.

This is being developed for less industrialized

communities in special groups such as refugeesand people living in financially deprivedcommunities who are unable to obtain a restorativedental care.

ART has broken many barriers and allowed deliveryof dental restorative treatments possible despiteunavailability of electricity or communities that cannot afford dental treatment.

CONTINUED


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CONTINUED

Glass Ionomer is the material of choice for ART thatcan be applied to early stages of caries

development that would halt or slows the caries

progression due to the slow release of fluoride.

It is important to understand that ART is only abranch of oral health care that need to start with

health promotion messages, healthy diet and good

oral hygiene.

With ART one attempts to conserve as much tooth

structure as possible to prevent further decay to

achieve the goal ofTeeth forLife.

CONTINUED


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CONTINUED

Instrument needed for ART is very convenient to carryaround by bus or bicycle in a bag.

In addition delivering this treatment oral care workers

travel to rural communities for oral health education.

ART is a very friendly procedure to patients that could beutilized to be effectively used on children and fearful

adults.

For this reason, ART is widely used even in industrialized

countries because it supports minimal intervention andminimal invasion of the patient.



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Removing carious tissuesusing hand instrumentsonly

Less traumatic No need for electricity

Conservation of toothstructure

Low cost

Glass Ionomer

Bonds to tooth

Releases fluoride

ART Applications


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Great technique for root cariesGood alternative in field conditions

Excellent for fearful children

Good alternative in medicallycompromised patients

Good alternative in mentally

compromised


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PRINCIPLES OF ART


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PRINCIPLES OFART

2 main principles of ART are:

1. Removing carious tooth tissues using handinstruments only

2.

Restoring the cavity with a restorative material thatsticks to the tooth.

Why GIC?

It bonds chemically to both enamel and dentine, it isfluoride releasing and it does not inflame gingiva orpulp.


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INDICATION AND CONTRAINDICATIONS


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Indications:

There is a cavity involving dentine

Able to access the cavity with hand instruments.

Contraindications:

Presence of infection (abscess or fistula)

Pulp is exposed Chronic inflammation of pulp

Cavity is inaccessible with hand instruments.

PREPARING THE CAVITY


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Place a cotton roll and dry the working tooth. Use the dental hatchet to gain access and

excavators to remove soft caries and unsupported

enamel.

It is very important that:

1. All soft caries is removed at enamel-dentine

junction.

2. To avoid exposure of pulp in deep cavities, leave a

small portion of affected dentine near pulp region.


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CONTINUED


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After 1-2 minutes check the occlusion.

If the ART restoration too high, remove the stained

portion of restoration with a carver blade.

Ask the patient not to eat for an hour.


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PROCEDURE FOR RESTORING

MULTIPLE SURFACE CAVITIES


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MULTIPLE SURFACE CAVITIES

Prepare the cavity in a dry environment usingcotton rolls.

Place a matrix strip between teeth with a wedgefor support under the contact point and gummargin.

Condition the cavity and fill it with GICcompletely.

Use the finger press techniqueRemove excess and wait for 1-2 minuets.

Check the occlusion and it is important to havenon occluding contacts with the opposing tooth.


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PRESS-FINGER TECHNIQUE


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PRESS-FINGER TECHNIQUE


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AFTER PRESSING


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AFTER APPLYING WATERPROOFING


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SURVIVAL OF GIC SEALANTS3 year old glass-ionomer sealant


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y g

SURVIVAL OF GIC SEALANTS2 year old glass-ionomer sealant


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MONITORING


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It is important to collect any information if any painis being experienced and if ART restoration was

accepted.

Assess if the patient is satisfactory with the

restoration within first 4 weeks. The clinical evaluation is planned annually or

biannually depending on the risk statues and oral

hygiene.

FAILED OR DEFECTIVE RESTORATION


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A restoration is no longer satisfactory when :1. It is completely missing

2. Fractured restoration

3. Much of the restorative material is worn away.

4. Caries have developed at the restoration marginor else where on the tooth surface.


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Use of Stainless Steel Crowns


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u Introduced to pediatric dentistry by Dr. William

Humphrey in 1950

prior to that orthodontic bands filled with

amalgam were a last resort necessity is the mother of invention

u Considered superior to large multisurface

amalgam restorations and have a longer clinical

lifespan than two or three surface amalgams

(Dawson et al., 1981)

Objectives


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j

u The student should be able to:

Describe the indications for stainless steel

crowns.

Understand the principles of preparation,

adaptation, and cementation of a successful

stainless steel crown.

To properly prep a dentoform tooth for a SSC

and properly adapt a crown to fit it.

Crowns vs. Class II Amalgams


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g

Crowns 90% successful from date

of placement, regardless

of age

Majority of failures are

related to pulp failure, not

restoration failure (false

failure)

Not as esthetic however

More expensive

Class II Amalgams Success rate is highest

when life expectancy of

the tooth is less than 3

years

Better looking than

crowns

Cheaper than crowns

Approximately 50%

failure rate when placed

in children


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Rampant Caries Caries involving three or more surfaces

Recurrent caries

Following pulp therapy

Developmental defects

Fractured teeth

Severe bruxism

Orthodontic appliance fabrication


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Indications


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Rampant caries

Three surface radiographic decay

.:Indications


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Indications


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Non-ideal two surface, or 3 surface decay

:Indications

Recurrent caries


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.:Indications


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Indications Developmental Defects


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.:Indications Fractured amalgams

.:IndicationsSevere Bruxism


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Severe Bruxism

.:IndicationsOrthodontic Appliance Fabrication


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Crown / loop

Distal Shoe

Contraindications


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u Esthetics

u Teeth that are nearing exfoliation

u Mechanical problems space loss

caries beneath the level of the bone

u Permanent restoration in the permanentdentition

Types of Crowns


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Rocky MountainUnitek

Ion

Types of Crowns


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Rocky Mountain

First crown developed,originally by an orthodontist

Must be trimmed Must be contoured

Not crimped

Rarely used today due to

significant time to fabricate at

chairside

Types of Crowns


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Unitek

Second crown developed

Pre-trimmed

Must be contoured Must be crimped

Primarily composed of

chromium and steel, this is

strongest of the three crowns

Types of Crowns


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Ion

Latest evolution

Pre-trimmed

Pre-contoured

Pre-crimped

Softer metal, but designedto snap over prep without

any alterations

What you will need


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u Burs and stones

#169

heatless stoneu Pliers and instruments

contouring plier

crimping plier

u Polishing

Clinical Procedures

Pre-treatment evaluation


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Pre treatment evaluation

Prior to placing rubber dam, check occlusion

Vertical space loss? Horizontal space loss?

Soft tissue change? Mobility?

Rubber dam is mandatory!!! Crowns are

very slippery when wet with saliva

Must have adequate anesthesia, particularly

on the palate.


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Horizontal space loss: #E has shifted mesially into #D

Vertical Space loss: U #E has palatal cusp erupted into L #E

caries


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Squares vs. rectangles (maxillary molars vs. mandibular molars) -

Hint!!! - distal caries on a mandibular primary first molar

will alter its shape to look more like a square! When this

happens, choose a maxillary primary first molar crown from the

opposite arch (I.e. - space loss on lower left primary first molar.

Choose a crown from the upper right box!!!)

Managing Space Loss


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Another technique for managing space loss

Using the Howe plier, grasp the Unitek crown

on the marginal ridges and gently squeeze

This causes the rectangular crown to become

square. Doing this reduces the mesio-distal

width of the crown, but inceases the bucco-

lingual widthRecontour and recrimp the crown.

Overview


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u Occlusal reduction

u Proximal reduction

u Buccal and lingualreduction

u Beveling

u Round all sharp lineangles and corners

Crown preparation


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Key points to rememberThis is not a cast restoration. The crown does

not rely on a precision fit. Retention relies on

the natural undercuts, the adequacy of thecrimp, and the luting material.

This prep is completely different from that of a

full gold crown prep

Excessive buccal/linqual reduction may result

in a non-retentive crown and an unplanned

extraction!

Crown Preparation

Armamentaria


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Armamentaria

Burs ---

No. 169L FG

Tapered Diamond FG

No. 6 or 8 RA

No. 330 FG

Heatless Stone

Accessories---

Wire wheel

No. 114 contour pliers

No. 800-417 crimping

pliers

Howe pliers

Crown Preparation


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Occlusal reduction

Occlusal beveling

Interproximal reduction

Line angle refinement

Crown Preparation


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Occlusal Reduction - prior to preparation

Crown Preparation


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Occlusal Reduction - using a 330FG or a round wheeldiamond, remove approximately 1-1.5mm.

Crown Preparation Occlusal bevel - use 330FG or tapered diamond


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Occlusal bevel use 330FG or tapered diamond

Occlusal Reduction - 1.0-1.5mm


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Occlusal Reduction - 1.0-1.5mm


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Completed Occlusal Reduction


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u Check reduction with

opposing arch

Crown Preparation Occlusal reduction completed - do not over-reduce the


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p

mesiobuccal aspect (high pulp horn)!!!

Proximal Reduction

Contact with adjacent teeth must be broken


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u Contact with adjacent teeth must be broken

gingivally and buccolingually

u proximal slices converge slightly toward the

occlusal and lingual

DO NOT OVER TAPER

u The gingival margins should have a feather-

edge finish lineu Adjacent tooth structure must not be damaged

Proximal Slices


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Crown Preparation Interproximal reduction - tapered diamond used to avoid


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interproximal ledges which can prevent seating!!!

Crown Preparation


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Completed preparation - should be approximately

1 - 1.5 mm below the plane of occlusion as judged

by comparing adjacent marginal ridge height.

Should be no sharp angles to prevent crown fromseating

Must not be ledged interproximally

Margin should be approximately 1 mm below themarginal gingiva

Crown Preparation


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Crowns for Guiding Teeth

Ectopic Eruption


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Ectopic Eruption

Crown is indicated on a second molar AND the

permanent first molar is hold-type ectopic



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Techniques

Pulp treatment is

completed in the usual

manner

Estimate amount of

distal reduction

required

Carefully reduce so

that first molar is not

damaged

Estimated reduction


Technique (cont)


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Technique (con t)

Using perio probe,

sound the mesial of

the permanent molar

Unitek crown is

trimmed so that thedistal margin

extends below the

mesial marginal

ridge of the firstmolar. Solder???

Crowns as Space Maintainers


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The primary advantage ofusing a crown instead of a

band is the increased

stability.

May be a one or two step

procedure (usually two)

Angulation of Slices


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Proper slice Improper slice

Ledging


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u Proximal slice must

be extended below

tissue to to avoid

leaving a ledge

Preserving the Outline


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u Remember: crown preparation if a significant part

of the crowns retentive potential


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Round Sharp Line Angles


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u The buccal and lingual proximal line angles

are rounded by holding the bur parallel to

the tooths long axis and blending the

surfaces togetherThe finished contour

should conform to the internal contour of

the stainless steel crown

Crown Adaptation


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u Mark gingival line with a

scaler & trim 1mm beneath

the mark using C&B

scissorsMargins should betrimmed to lie parallel with

the contour of the gingival

tissue and consist of a

series of curves withoutsharp angles

Guidelines

u Resistance in seating without tissue blanching.


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Check for high spots on occlusal surface

ledges

u Resistance in seating with tissue blanching.Check for

crown too wide (preliminary contouring)

crown too longtissue caught in margin

Contour the Crown


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u Use contouring pliers,

bend the gingival third

of the crowns marginsinward to restore

anatomic margins and to

reduce the marginal

circumference ensuring a

good fit

Crimp the crown


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u With the crown-

crimping plier (#118)

crimp the margin

Replace crown ontooth and check

margins with an

explorer

Finishing and Polishing


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u Use heatless stone to

smooth jagged

edgesThen use a

rubber wheel toremove small

scratches and

smoothPolish surface

of crown to a highshine with tripoli and

rouge

Cementation


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u Clean crown and toothu Fill crown with zinc

phosphate cementSeat

crown, expressing

cement form allmargins and press into

occlusionRemove

excess cement when

partially set

Cross-sectional View

Post-op instructions ?


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u Although a well-adapted and

cemented crown

should not come offunder these

circumstances,

patients and parents

should be warned

of the possibility

Managing Clinical Variations


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u Space Loss

Managing Space Loss


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u May need to increasethe buccal and

lingual

reductionsMay needto compress crown

form on mesial and

distal with Howepliers


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Composite Crowns

BY DR. SAMI MALIK ABDULHAMEED

Objectives


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u To describe the indications for a composite

crown on a primary incisor.To properly

prepare a dentoform tooth for a composite

crown.To properly adapt a crown form andto restore a dentoform tooth.

Restoration of Class IV Caries in

Primary Anterior Teeth


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u Esthetic ResinRestoration

u Stainless Steel Crown

u Open-Face SteelCrowns

u Composite Crowns

Anterior Stainless Steel Crowns


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u Esthetics - poor

u Durability - very good

u Time for placement - fastest

u Selection criteria - severely decayed,

esthetics of minimal importance, gingivalhemorrhage not controlled, inadequate

patient cooperation

Open Faced Stainless Steel Crown


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u Esthetics - okay

u Durability - good, although facing may bedislodgedTime for placement - takes longest

to place due to two-step procedureSelection

criteria - severely decayed teeth, durabiltyneeded, esthetics are a concern

Crown Form Selection


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u Select the appropriate crown form size

from the mesio-distal measurement (mm)

of the tooths incisal edge, or by direct

comparison


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Utilize a fine diamond or a 699


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Tooth Preparation


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u Buccal reduction - to allow the placement of

the restoration within the normal buccal

lingual width of the tooth restored

.5-1 mm

u Lingual reduction - to allow for the

necessary bulk for the strength of the crown

and to prevent for any occlusal interferences

Buccal Reduction


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Lingual Reduction


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Circumfrential Undercut Shoulder


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u Terminates at the crest of the gingiva

u Shoulder depth should be .75-1 mm

u Use inverted cone

Variation

Cervical undercut on facial only


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Removal of caries may also provide undercuts

Crown Adaptation


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u Carefully trim off the

cervical collar with

curved festooning

scissorsTrim crownform so that when

seated, it covers the

shoulder but extends

no more than 1 mmpast tge shoulder

Trial Fitting of Crown Form


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u Try on trimmed crown

form Incisal edges

should line up Place

hole in incisal edge ofcrown with an

explorer to allow vent

for composite to flow

through during crownplacement

Crown Placement

u Etch tooth with phosphoric acid for 30

d


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seconds

u Thoroughly wash and dry etched surface

u Apply bonding agent according to

specifications

Crown Placement


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u Carefully pack the

crown form resin to

avoid entrapment of

air bubbles

i i h fill d


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u Position the filled

crown form over the

prepared tooth so it

extends 1mm over thegingival

marginRemove excess

resin from margins

with an explorerbefore polymerizing

u Slice crown form

Minimal Finishing and Polishing

P l i f


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u Peel it away from

composite crown

u Finish margins

u Adjust occlusionu DO NOT FINISH the

labial surface

polymerization of the

resin against the plastic

provides the smoothest

and most stain resistant

surface


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restorations in pediatric dentistry

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