PRESENTED BY,Shiji margaret

CRRI

CONTENTS•History•Introduction•Types of crown•Types of stainless crown•Classification of stainless steel crown•Indication•Objective of stainless steel crown•Advantage•Disadvantage•Composition

•Factors to be considered in pre –operative evaluation•Clinical procedure•Tooth preparation•Reduction•Method of placing•modification•complication•conclusion•reference

HISTORY

Stainless steel crown was first introduced as chrome steel crown by william humphrey stainless steel crown were introduced to pediatric dentistry by rocky mountain company in 1947First used in the late 1940s and became commonly used in the 1960s

INTRODUCTIONSTAINLESS STEEL CROWN IS A SEMI PERMANENT RESTORATION USED IN PRIMARY AND YOUNG PERMANENT TEETH.STAINLESS STEEL CROWN IS USED IN DECIDUOUS DENTITION THAN PERMANENT DENTITION BECAUSE OF 2 REASONSTHAT IS DECIDUOUS TEETH CARIES CAN DESTROY THE TOOTH FASTER THAN PERMANENT. AND ALSO IN DECIDIOUS TOOTH PULP IS LARGER THAN PERMANENT AND ENAMEL AND DENTIN THICKNESS IS LESS.STAINLESS STEEL CROWN IS AN EFFICIENT AND RELIABLE METHOD OF RESTORATION OF DECIDUOUS DENTITION.

Types of crowns

•Stainless steel

•Nickel chromium

•Veneered stainless steel crowns

•Strip crown

•Ceramic crown

Types of stainless crowns

Rocky mountain

Ormco company

Unitek

3M company

Classification of stainless steel crowns

Untrimmed- crowns are neither

trimmed nor contoured Pretrimmed- crowns have stright

non-contoured sides but are festooned to line parallel to the gingival crest.they still require contouring and trimmingPrecontoured – these are

festooned and precountoured though a minimal amount of trimming may be necessary

Based on shape

indication extensive decay in primary and young permanent tooth

Teeth deformed by developementaldefects or anomaliesTeeth with hyperplastic defects

Following plup therapy

As a preventive restoration

As an abutment

Temporary restoration of a fractured tooth

In severe cases of bruxism

Single tooth cross bite

For replacing prematurely lost anterior teeth

Objectives of using

To achieve biologically compatible , competent for mastication and clinically acceptable restoration.To maintain the form and function and where possible the vitality of the tooth should be maintained.

Can be used for badly broken down crownCan be placed with poor isolationEconomicalFull coverage-prevents recurrent decayAcceptable for both patient and dentist

ADVANTAGES

disadvantages

The aesthetics is not fair

compositionStainless steel

crown

17-19% chromium10-13% nickel67% iron4% minor elements

Nickel base crown

72% nickel14% chromium6-10% iron0.04% carbon0.35% manganese0.2% silicon

Factors to be considered in pre-operative evaluation

Dental age of the patientCo-peration of the patientMotivation of the patient

Medically compromised/disabled

children

Evaluate the preoperative occlusion•Take the alginate impression of U/L jaws.•Pour the cast with dental stone•Note the dental midline and the cusp fossa relationship bilaterally

Clinical procedure

Selection of crown •The correct size crown is selected by the M-D dimensions of the tooth to be restored using Boley gauge.•To produce steel crown margins of similar shape examine the contour of gingiva of the buccal & lingual marginal gingiva.

Tooth preparation

L.A. should be administrated

Isolation by rubber dam or cotton rolls

Remove the decay

Reduction

Occlusal reductionA 69L or 169L bur is used to reduce the occlusalsurface by 1.5-2.0mm .

Proximal slicesplace the wooden wedges in the inter proximal embrasures, the 69L bur is moved B-L across the proximal surface.

Buccolingual reductionReduction of buccal and lingual surface is minimalRound off all the line angles It is done by using side of bur

The crown should be of a correct length and its margins should be adapted closely to the tooth.

For shaping the crown margins mark 3 light

points on the metal at the (mesiolingual, lingual and distolingual)and at (mesiobuccal, buccal, distobuccal) surfaces at the crest of respective marginal gingiva without compressing the marginal gingiva.Final finished margins are placed approximately 1mm below these marks.

Initial adaptation of crown

Now the crown is tried on the preparation by seating the lingual first and applying pressure in a buccal direction so that the crown slides over the buccal surface into the gingival sulcus.Resistance should be felt as the crown slips over the buccal bulge.

Seating the crown

Crown contouring

Initial crown contouring is performed with a114 plier (ball and socket plier) in the middle 1/3rd of the crown to produce belling effectThis will give the crown more even curvature

This is very important to the gingival Health of the supporting tissue.Using the no.417 crimping pliers the crown is crimped in the gingival third.After completion of crimping there will be gradual bend in the gingival third of crown.The use of crimping is for the protection of soft tissues.

Uncrimped v/s crimped

Checking the final adaptation of the crown

The crown should be replaced on the preparation after the contouring procedure to see that it snaps securely into place.The occlusion should be checked at this stage to make sure that the crown is not opening the bite or causing a shifting of mandible into an undesirable relationship with opposing teeth.

Accumulation of plaque and inflammation of gingiva is commonly seen in practice of restorative dentistry due to rough and unpolished restoration.To avoid these complications crown should be polished prior t o cementation with rubber wheel to remove all scratches.

Finishing and

polishing

Radiographic confirmation of the gingival fit

Before cementation a bitewing is taken to verify proximal marginal integrity

Cementation

SSC should be cemented only on clean dry mouth, isolation of teeth with cotton roll is recommended.Rinse and dry the crown inside & out side and prepare to cement it.A zinc phosphate, polycarboxylate or GIC is preferred.

Before the cements set ask the patient to close into centric occlusion by applying pressure through a cotton roll and confirm that the occlusion has not been altered.

Remove the excess cement by an explorer or scaler & for interproximalarea can be cleaned by passing dental floss through them.

result

Confirm occlusion

In 1971, Mink & Hill report several way of modifying the stainless steel crown when they are either too large or too small1. Undersize tooth or the oversize

crown.2. Oversize tooth or undersize crown.3. Deep subgingival caries.4. Open contact.5. Open-faced stainless steel crown.

Stainless steel crown modifications

Interproximal

ledge.

Crown tilt.

Poor margins.

Inhalation or ingestion of crown

conclusion

The stainless steel crown is in the superior durability and longevity to class II amalgam in primary teeth

referenceDentistry for the child and adolescent 9th

edition , McDonald

Text book of pediatric dentistry 3rd edition, S.G damle

Principles and practice of pedodontics 2nd

edition , arathi rao

Text book of pediatric dentistry 2nd edition, nikhil marwah

Text book of pedodontics 2nd edition shoba tandon

Hand book of pediatric dentistry , 3rd

edition, angus c cameron and richard p widmer

Clinical pedodontics , 4th edition, finn

Fundamentals of pediatric dentistry, 3rd

edition, richard j mathewson and robert e primosch

Pediatric dentistry principles and practice, MS muthu and N sivakumar