CONTENTS Types of crown
Different type of Stainless Steel Crown
Objective of Using
Advantage
Disadvantage
Composition
Indication
Factor s to be considered in Pre-Operative Evaluation
Clinical Procedure
Tooth Preparation
Steps in Reduction
Initial Adaptation of Crown
Seating the Crown
Crown Contouring
Crown Crimmping
Checking Final Adaptation of Crown
Finishing and Polishing
Radiographic Confirmation of Gingival Pit
Cementation
Result
Confirm Occlusion
Stainless Steel Crown Modifications
Complications
Reference
INTRODUCTION
Stainless steel crown is a semi permanent restoration
used in primary and young permanent teeth.
It was introduced as chrome-steel crown by
‘Humphrey’ in 1950.
Stainless steel crown is more frequently used in
deciduous dentition than permanent dentition .
Stainless steel crown is an efficient and reliable
method of restoration of deciduous dentition.
TYPES OF CROWN
•Stainless steel
•Nickel chromium
•Veneered stainless steel crowns
•Strip crown (ZIRCONIA)
•Ceramic crown
DIFFERENT TYPES OF STAINLESS STEEL CROWN
1) Untrimmed - These crowns are neither trimmed nor contoured thus require lot of adaptation and are time consuming.
Eg :- Rocky Mountain.
2) Pretrimmed - These crowns have straight non-contoured sides but are festooned to line parallel to the gingival crest. They
still require contouring and trimming.
Eg : - Unitek Stainless steel Crowns and 3M Co.
3) Precontoured - These crowns are festooned and are also precontoured though a minimal amount of festooning and trimming
may be necessary. Eg : - Unitek Stainless steel Crowns and 3M Co.
Untrimmed : Neither trimmed nor contoured
Pretrimmed : Crowns have straight non-contoured sides.
Precontoured : Crowns are festooned
DIFFERENT TYPES OF STAINLESS STEEL CROWN
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.
ADVANTAGES
These crowns are more superior to multisurface amalgam
restoration with respect to life span, replacement , retention and
resistance.
They are acceptable to both patient and dentist
They are more cost effective because of comparatively simple
procedure involved in restoring even severely affected primary
molars
DISADVANTAGE
The aesthetics is not fair
COMPOSITIONSTAINLESS STEEL CROWN
•17-19% - chromium
•10-13% - nickel
•67% - iron
•4% - minor elements
NICKEL-BASE CROWN
•72% - nickel
•14% - chromium
•6-10% - iron
•0.04% - carbon
•0.35% - manganese
•0.2% - silicon
INDICATIONS
Extensive decay in primary and young permanent tooth
Teeth deformed by developemental defects or anomalies
Teeth 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
FACTORS TO BE CONSIDERED IN PRE-OPERATIVE
EVALUATION
Dental age of the patient
Co-operation of the patient
Motivation of the patient
Medically compromised/disabled children
CLINICAL PROCEDURE
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
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
STEPS IN REDUCTIONOCCLUSAL REDUCTION
A 69L or 169L bur is used to reduce the occlusal surface by
1.5-2.0mm .
PROXIMAL SLICES
Place 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 minimal
ROUND OFF ALL THE LINE ANGLES It is done by using side of bur
INITIAL ADAPTATION OF CROWN
•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.
SEATING THE 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.
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
effect
•This will give the crown more even curvature
CROWN CRIMPING•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.
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.
FINISHING AND POLISHING
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.
RADIOGRAPHIC CONFIRMATION OF THE GINGIVAL FIT
Before cementation a bitewing is taken to
verify proximal marginal integrity
CEMENTATIONSSC 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
interproximal area can be cleaned by passing dental floss
through them.
RESULT
CONFIRM OCCLUSION
STAINLESS STEEL CROWN MODIFICATIONS
In 1971, Mink & Hill report several way of modifying the stainless steel crown when they
are either too large or too small
• Undersize tooth or the oversize crown.
• Oversize tooth or undersize crown.
• Deep subgingival caries.
• Open contact.
• Open-faced stainless steel crown.
COMPLICATIONS
• Interproximal ledge.
• Crown tilt.
• Poor margins.
• Inhalation or ingestion of crown
REFERENCE
•Shobha Tondon