Resin Composite fall 12.pdf

8/17/2019 Resin Composite fall 12.pdf

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Resin Composite

Restoration

Dr Mohamed Shabayek

Lecturer, Operative Dentistry

Department


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Composite Material

• A product which consists of at least twodistinct phases

– blending together components

– different structures and properties. – example: Concrete, Tooth structure


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Advantages of resin composite

Tooth colored Esthetic


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Adhesive No need for mechanicalretention Conservative



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Numerousapplication

Restorative

Fissure sealant

Core material

Ability to accept repair andcorrection

Low thermalconductivity

No base is needed



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• Command setting using light curing



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Disadvantages:

• Polymerization shrinkage.


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• Technique sensitivity

Disadvantages:

Isolation

Etch

Rinse

Adhesive

Curing


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Contraindications

• Rampant caries


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Contraindications

• Large posterior

restorations

• Poor isolation


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Abnormalocclusal habits

Contraindications


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Clinical manipulation of resin

composites

1. Cavity preparation.

2. Color selection.

3. Application of adhesive.4. Insertion and manipulation of the

material.

5. Finishing and polishing.


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Cavity preparation

Outline form depends on:1. Extent of defect.The outline ends on the extent of the defect

2. Proximal contacts.

It is not necessary to involve all the contact area inthe outline.

3. Accessability.

Palatal access is preferred especially in class III.


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Important

• It is better to end up all the cavity margins

in sound enamel.


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Bevel the external enamelmargins to:

• Expose the ends of the enamel

rods instead of the sides. Thisprovides better adhesion.

• More available enamel rods foradhesion.

• Expose fresh non carious enamel

with less fluoride content.

• Mask the line of demarcationbetween the restoration andenamel.

• Achieve better esthetics as itallows for unnoticed gradualcolour change.


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to bevelnotWhen

Direct

occlusalcontacts

Thin cervical

enamel


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• Retention form

Micromechanical bonding of composite tothe tooth structure.

• Resistance formThrough conservation of tooth structure.


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Correct bur positioning for the

palatal approach.

• Avoid bur slippage

towards the

adjacent tooth.


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Removal of decay

Remove the caries with a round bur or an

excavator without creation of a definite

cavity wall.


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Finishing of cavity walls•

Undermined enamel should be removed.• An undermined enamel wall could be left as long

as it is:

1.Sound (free of caries).

2.Thick enough to withstand possible forces.3.Not discoloured.

4.Of esthetic importance

Toilet of the cavity• Removal of debris, saliva, blood and etc.,


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Types of tooth preparation

• Conventional.

• Bevelled conventional.

•

Modified.


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Conventional tooth preparation

• Butt joint junctions.

• Definite walls and floors.

• No bevels.

• Macromechanical means of retention (grooves,dovetails and undercuts)


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Beveled Conventional preparation

• Similar to conventional

but with beveledenamel margin.


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Modified preparation.

• No specified wallconfiguration, no specificpulpal or axial depths.

• Preferably havingbevelled enamel margins.


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•

Bevelling is restricted to the incisal and proximalwalls only in case of thin cervical enamel wall oravoiding subgingival extension.

• In case of inability to control moisture, an

alternative to composite like GI or amalgamshould be considered.

Class V

Documents

Resin Composite fall 12.pdf