2.alternatives to anterior crowns

7/29/2019 2.Alternatives to Anterior Crowns

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Alternatives to anterior crowns1. Bleaching: with hydrogen peroxide or other

oxidizing agents2. Composite or glass ionomer restorations:

although they sometimes deteriorate, it ispossible to replace them without destroying

more tooth tissue.3. Gold or porcelain inlays: the conventionalway to restore a class IV incisors was a goldinlay with or without a facing or with a crown.Today, acid-etch retained composite

restorations have completely replaced class IVgold inlays

similarly, porcelain inlay for class V havealmost disappeared because the cost and the

time factors


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4. Veneer restorations: composite orporcelain .

Advantages for composite:

Easier to produce the marginal gingival edge.

Can be placed as a provisional restoration.

Without preparation it is reversible.

Simple and quick to apply at the clinic. Less expensive

Can be repaired and adapted.

Disadvantages of composite:

Discoloration and wear. Difficult to produce graduated colour along the length

of the tooth

Difficult to mask a deeply discoloured tooth.


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Advantages of porcelain:

better resistance to discolouration and

wear.

better appearance and graduated colour.

Disadvantages of porcelain:

Expensive.

Less satisfactory marginal gingival edge.

Prognosis decreases when bonded todentin.


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Indications for posterior crowns

Badly broken-down teeth: the most commonindication for posterior crown. Usually resultingfrom large cavities and repeatedly failedrestorations. In most cases a build up core of

amalgam retained by pins is to be made beforethe crown.

Root filled teeth: root filled teeth are more likelyto fracture than vital teeth. This dont mean that

all root filled teeth should be crowned.

As part of another restoration: for example asretainers for a bridges and fixed splints


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Alternatives to posterior crowns

Gold inlays

Pin-retained amalgam restorations: it isnot justified to crown all teeth with large

cavities just as a preventive measure.

Because it would be an over treatment

and not cost-effective. Its best to crown

when there is a clear risk of a restorationfailure.


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pins


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Tooth-coloured posterior restoration:

the most common restorative material used for posteriorteeth is amalgam. But because of the increasing anxietyin some parts of the world of the mercury toxicity orallergy, there are some patients who will refuse to havean amalgam restoration. This has encouraged thedevelopment of a satisfactory, cost-effective alternativematerial to restore posterior teeth.

But some dentists feel that these materials are notcomparable to amalgam in the large restorations. Thesedentists will therefore prescribe crowns more thancomposite restorations.

There are good evidence that a layered restoration canproduce a stronger tooth than an amalgam restoration ora gold inlay.


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eramic inlays: share some of thedvantages of posterior composite

estorations because they are: acid-etched,hey strengthen weekend cusps and they are

ooth coloured. In addition the porcelain

cclusal surface is more wear-resistant and

here is no polymerization contraction.ere are tow systems to make ceramic inlays:

ne that includes a laboratory stage and the

ther is CAD or CAM (computer aided design

r computer aided manufacture).


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Ceramic inlays


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CAD


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Choosing the right posterior

restorationThe available options are:

An amalgam,composite or glass ionomer cement.

A layered restoration.

An amalgam with pins.

A ceramic inlay.

A gold inlay.

A gold inlay with occlusal protection (onlay)

A partial crown.

A complete crown.

A core and a partial crown.

A core and complete crown.


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Preparation for a partial crown


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Build-up core and a preparation for

a complete crown


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The decision depends on:

1) Appearance

2) Problems of retention

3) Problems of strength of the remaining toothtissue and the restorative material.

As far as appearance is concerned, a compositerestoration, a ceramic inlay and a crown will be

indicated for large restorations.When the problem is retention, an amalgam

restoration with pins is chosen.

When the remaining tooth tissue is week a layered

restoration, a ceramic inlay or a cuspalcoverage gold inlay.

2.alternatives to anterior crowns

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