Stainless Steel Crown
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Transcript of Stainless Steel Crown
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