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Stainless steel crowns
1. A . Mahesh kumar
Pg 1st year student
Dept of pedodontics &
preventive dentistry
Dr s&n sids
2. Contents
INTRODUCTION
HISTORY
OBJECTIVES
INDICATIONS OF STAINLESS STEEL CROWN
FACTORS TO BE CONSIDERED IN PRE-OPERATIVE
PROCEDURE
CONTRAINDICATIONS OF STAINLESS STEEL CROWN
TYPES AND SIZE OF STAINLESS STEEL CROWN
COMPOSITION OF STAINLESS STEEL CROWN
3. contents
ARMAMENTARIUM FOR SS CROWN
RESTORATIONS
CLINICAL PROCEDURE
TOOTH PREPARION
CROWN PREPARATION
MODIFICATIONS OF STAINLESS STEEL CROWN
COMPLICATIONS
CONCLUSION
REFERENCES
4. REFERENCES
Kennedy’s Pediatric Operative Dentistry_ Curzon, kennedy
DB, Roberts
Pediatric dentistry total patient care _Stephen H.Y
Fundamentals of Pediatric Dentistry_ Richard. Mathewson
Dentistry for child and adolescent_ Ralphe Mc Donald,
Avery.
Text Book Of Pedodontics_ Shobha Tandon
Clinical Pedodontics_ Sidney B Finn
Pediatric dentistry-Infancy through adolescence_ Pinkam
5. M memarpour ,D Reza M Razavi Comparison of
microleakage from stainless steel crowns margins used
with different restorative materials: An in vitro studyDent
Res J 2016 Jan-Feb; 13(1): 7–12.
Shah, Purvi V.; Lee, Jessica Y.; Wright;(2004) Clinical
Success and Parental Satisfaction With Anterior
Preveneered Primary Stainless Steel Crowns Pediatric
Dentistry, Volume 26, . 391-395(5).
Preformed metal crowns for primary and permanent molar
teeth: REVIEW of the Literature_ Ros C Randall. Pediatric
dentistry, 24; 5:2002.
Efficacy of preformed metal crowns Vs amalgam
restorations in primary molars. A systemic Review. JADA,
131:337-440; march2000.
6. INTRODUCTION
The preformed metal crown (PMC), more commonly
known as the Stainless steel crown (SSC) has been used
for approximately 50yrs.
Preformed metal crowns for primary molar teeth were
first described by Engel followed by Humphery in
1950
First used in the late 1940’s and became commonly used
in the 1960’s
The SSC offers an outstanding alternative to other
restorative materials for restoration of both primary
and permanent teeth
7. History
1950: The first preformed crowns marketed
1960: Significantly improved crown festooned margins
to correspond to the cervical aspect of the tooth
Recently: introduced nickel-chromium crown differs
distinctly from the earlier crowns. It is manufactured
from the alloy Iconel with very small amount of iron as
compared to older stainless steel.
Hence, Iconel 600 is not considered as a stainless steel
crown.
8. Objectives
The objectives of stainless steel crown restoration are:
1) To achieve biologically compatible masticatory
component and clinically acceptable restoration.
2) To maintain the form and function of tooth and
where possible, the vitality of the tooth should be
maintained.
9. Indications for ssc
After pulpotomy or pulpectomy specially the first
primary molar. High incidence of amalgam isthmus
fracture.
When three or more surfaces need restoration.
As an abutment for fixed appliances.
High caries index patient.
During general anesthesia full mouth Rehabilitation.
11. Indications
Nash made the point that carrying out a crown prepa-
ration of a tooth solely for use as an abutment is
destructive to tooth tissue and that bands are
preferable to support appliances to preserve arch
space.
When both a crown and space maintainer are
required, the space maintainer should be attached to a
band cemented over the crown; with this arrangement,
subsequent removal of the space maintainer leaves an
intact and smooth crown surface.
13. Indications for ssc
If extensive abrasions
Temporary restoration of fractured tooth.
In severe cases of bruxism
For replacing prematurely lost anterior teeth
For teeth deformed by developmental defects or
anomalies
For teeth with hypoplastic defect
Single tooth cross bite
16. Indication
In a recent studies, Pinkerton suggested that indica-
tions for placement of a PMC should include child
patients who are unlikely to attend regular recall
appointments or who are unlikely to be reliable
preventive patients.
17. FACTORS TO BE CONSIDERED IN
PRE-OPERATIVE PROCEDURE
Dental age of the patient:
This is recorded by the root development of the
underlying tooth. When a primary tooth can be
expected to exfoliate within 2 years of restoration,
amalgam restoration can be done
Cooperation of the patient:
If the patient is uncooperative, whether it is due to age
(i.e.< 3 years) or due to negative behavior, if the child
is stubborn and does not want to cooperate, first a
positive behavior has to be installed
18. FACTORS TO BE CONSIDERED IN
PRE-OPERATIVE PROCEDURE
Medically compromised/disabled children:
Some of those patients might need prophylaxis as sub
gingival procedure is done (or) in poor general
condition of the child, chair side GA has to be taken
into account.
Motivation of the parent:
Whether the parents are willing to come for dental
visits for the follow-up.
19. CONTRAINDICATIONS OF
STAINLESS STEEL CROWN
If the primary molar is close to exfoliation with more than
half the roots resorbed or exfoliation within 6-12 months
Tooth exhibits excessive mobility
Partially erupted teeth
Where conservative restorations can be placed
In a patient with a known nickel allergy
20. TYPES AND SIZE OF STAINLESS
STEEL CROWN
They are available in six sizes for each primary tooth
and first permanent molars. A size 7 is available for
large teeth.
Untrimmed crowns (e.g. Rocky mountain)
Pretrimmed crowns (e.g. Unitek stainless steel
crowns, MN and Denvo Crowns, Denvo Co. Arcadia
CA)
Precontoured crowns (e.g. Ni-Chromium Ion crowns
and Unitek stainless steel crowns, MN, Sankuin copper
crowns).
21.
22. Untrimmed crowns
Neither trimmed
Nor contoured
Require lot of adaptation and are time consuming
eg. rocky mountain
Pre-trimmed crowns
Straight non-contoured sides
festooned to follow a line parallel to the
gingival crest
Still require contouring and trimming
Eg. Unitek stainless steel crown
27. COMPOSITION OF STAINLESS
STEEL CROWN
1. Stainless steel crowns:
(18-8) Austenitic type of alloy is used. E.g. Rocky
Mountain and Unitek.
The austenitic types provide the best corrosion
resistance of all the stainless steel.
-10-13% nickel
-17-19% chromium
-67% iron
-4% minor elements
28. COMPOSITION OF STAINLESS
STEEL CROWN
2. Nickel-base crowns: They are Iconel 600 types of
alloy.
-72 % nickel
-14% chromium
-6-10% Fe (Iron)
-0.04% carbon
-0.35% manganese, 0.2% silicon
29. There are three general classes of stainless steel,
1) the heat hardenable 400 series martensitic types,
2) the non-heat hardenable 400 series ferritic types
3) the austenitic types of chromium-nickel-
manganese 200 series and chromium-nickel 300
series.
30.
31.
32.
33. Mesio Distal Width of Crowns
Difference is 2mm
Average increase in size per each size is 1/3 mm
34.
35. Armamentarium For SS Crown
Restorations
Burs
Pliers
Instruments
Cementing Medium
Polishing & Isolation
42. CLINICAL PROCEDURE
Evaluate the preoperative occlusion:
Take upper and lower dental arch impressions with
alginate.
Pour the cast with the dental stone.
Note the dental midline and the cusp fossa
relationship bilaterally.
43. Selection of crown:
The correct size crown may be selected prior to the
tooth preparation by measuring the M-D dimensions
of the tooth to be restored and a Boley gauge can be
used for this purpose.
If the crown is not selected before the tooth reduction,
after the tooth reduction it can be selected as trial and
error procedure, which approximates the M-D widths
of the crown. The smallest crown that completely
covers the preparation should be chosen.
44.
45. To produce steel crown margins of similar shapes,
examine the contours of buccal and lingual gingiva.
Buccal and lingual marginal gingiva of the second
primary mandibular molar resembles smiles
Buccal marginal gingiva of the most mandibular first
molar (primary) and many maxillary first molars is
similar to a stretched out smile having greatest
occluso-gingival height located at the mesiobuccal
area.
The contour of lingual marginal gingiva of all the
primary molars resemble smile. The occluso-gingival
height is located about midway in buccolingual
direction.
46. Tooth preparation:
The aims of the tooth reduction are:
1) To provide sufficient space for the steel crown.
2) To remove the caries to have sufficient tooth for
retention of the crown.
47. ANTERIORS:
Preformed SSCs are considered to be the most durable &
reliable for restoring severely carious & fractured primary
incisors.
1) Croll described SSCs to be easy to place, fracture proof,
wear resistant and attached firmly to the tooth until
exfoliation.
2) The main disadvantage is the unsightly, silver metallic
appearance.
3)Mesial & Distal reductions are required to clear the
interproximal contacts.
4)The gingival margins should have no ledge or shoulder;
instead a feather edge at the free gingival margin.
48. 5) Incisal reduction is required to prevent unnecessary
elongation of the tooth.
6) Lingual reduction is necessary when the over bite is
complete such that the mandibular incisors are in
contact with the lingual surfaces of the maxillary
incisors.
7) The only reduction that should occur on the labial
surface is that which will remove caries.
49.
50. Recently resin veneered SSCs are available. The
problems faced by these are: can fracture while
crimping & are quiet expensive.
More recently a resin veneered crown- Dura Crown
was introduced.
They have labial gingival margin crimped & resin
adapted to the gingival edge of the anterior aspect of
the crown.
51. Apart from this,
-Polycarbonate crowns
-Strip crowns
-Artglass crowns
are also available to restore primary anterior tooth.
52. POSTERIORS:
A number of procedures must be performed before
starting the tooth preparation.
To eliminate the discomfort caused by cutting the
tooth and possible trauma to the soft tissues during
the trial fitting of stainless steel crown, there must be
adequate anesthesia of the tooth and the adjacent soft
tissues.
53. Isolation
Use of rubber dam for isolation is mandatory.
Before placing a rubber dam, check the child’s
occlusion. Observe for the following:
The opposing tooth has extruded due to longstanding
carious lesions.
There has been mesial drift due to carious lesions
changing the occlusion of the adjacent tooth.
Tooth reduction is needed so that the restored tooth can
be returned to normal function
54. Caries removal:
Remove the decay with large round bur in a slow speed
handpiece. After caries removal and pulp therapy, if
necessary, the previously carious area can be built up
with a quick setting reinforced ZnOE cement and / or
ZnPO4 cement.
55. Reduction of tooth:
Occlusal reduction-
Humphrey (1950) recommended that the cusps be
reduced, if necessary and that the four sides of the tooth be
reduced but as much tooth structure as possible be left for
retention.
Rapp (1966) advises that the occlusion of the tooth be
reduced so the height of the preparation is approximately
4mm from the gingival margin.
Mink and Bennett (1968), on the other hand, suggested a
uniform occlusal reduction of 1 to 1.5mm using a 1mm bur
to make grooves in the occlusal surface to guide the
reduction. .
56. Kennedy (1976), this should approximately follow the
anatomy of the tooth to a depth of 1.0 to1.5mm, which
allows sufficient space for the metal crown.
Reduce the occlusion by about 1.0 to 1.5mm. This is
determined by comparing the marginal ridges of the
adjacent teeth. (Mathewson)
In review, however, the best plan seems to be to reduce
the occlusal as the initial step since; gingival bleeding
will occur if the proximal reduction is done at the
initial step, making the diagnosis of very small pulp
exposure, difficult.
57.
58. Proximal reduction
The second step in the process of preparing the tooth
for a steel crown should be the interproximal
reduction.
It has been observed that many of the difficulties
countered in placing a stainless steel crown are the
result of attempting to fit a round or oval crown form
over a rectangular tooth preparation.
The primary principle of the technique for fitting steel
crowns is to make the tooth preparation fit the crown
form rather than attempt to make the crown fit the
tooth preparation.
59. Making a slice also helps to eliminate the
interproximal ledge, which seems to be the most
frustrating problem in the restoration of a tooth with a
steel crown.
Distal reduction is required even when there is no
erupted tooth distally. Failure to follow this
recommendation will result in an oversized crown
being fitted, which may impede the eruption of the
first permanent molar
61. Buccal and lingual reduction
The third step in the preparation concerns the reduction of the buccal
and lingual surfaces. This area seems to be the most controversial.
The questions is whether to (1) reduce the entire bulge, at least a
significant portion of it or (2) permit the buccal and lingual cervical
bulges to remain and reduce only the occlusal third of the preparation
The Buccal and Lingual surfaces are reduced atleast 0.5mm, with the
reduction ending in a featheredge, 0.5 to 1mm into the gingival sulcus.
It is usually not necessary to reduce the buccal or lingual surfaces. In
Some cases, however it may be necessary to reduce the distinct buccal
bulge, particularly in primary 1st molar.
All line and point angles in the preparation are rounded and smoothed.
62. Savid et al (1979) compared five different types of
preparations for retention capabilities:
(A) that recommended by Mink and Bennett, in which
only the occlusal third of both buccal and lingual surfaces
is reduced.
(B) that incorporating Class II preparations, in which the
buccal and lingual walls of the boxes converge toward the
occlusal.
(C) that which reduces the buccal and lingual
supragingivally to the crest.
(D) that which removes the supragingival bulge, extending
0.5 mm below the gingival crest, as recommended by
Troutman, with all undercuts on the buccal and lingual
surfaces removed.
(E) that which removes all supragingival tooth structure,
permitting only part of the anatomic crown to remain (i.e.
the tooth structure around which the crown would
normally be adapted).
63. Savide et al concluded that in the preparation of a
vital tooth, technique (A) might be indicated, because
of its conservation of tooth structure and its maximum
retentive value.
Two procedures are thought to be critical for obtaining
good retention (Rector et al 1985)
- Precise trimming of the crown with respect to the
gingival undercut.
-Adapting and crimping the crown along its entire
gingival margin.
64. Evaluation criteria for tooth
preparation:
1. The occlusal clearance should be 1.5 to 2mm.
2. Proximal slices converge toward the occlusal
and lingual, following the normal proximal contour.
(Mathewson)
3. An explorer can be passed between the
prepared tooth and the proximal tooth at the gingival
margin of preparation.
4. The buccal and lingual surface are reduced at
least 0.5 mm which the reduction ending in a feather
edge 0.5 to 1mm into the gingival sulcus.
65. 5. The buccal and lingual surfaces converge slightly
towards the occlusal.
6. All the line angles in the preparation are
rounded and smoothened.
7. The occlusal third of buccal and lingual
surfaces are gently rounded.
66. Tooth preparation for permanent
dentition
The preparation of a tooth for a permanent molar PMC is
essentially the same as for a cast metal crown but with a
reduction in the amount of tooth tissue removed.
It is important that the future preparation needs for a cast
restoration are kept in mind when preparing the tooth for a
PMC.
Fitting a permanent molar PMC requires significantly more
chairside time than a primary molar crown. An occlusal
reduction of about 1.5 to 2 mm is needed, and carrying this
out first enables the proximal reduction to be done more
easily.
67. The walls of the crown are prepared minimally so that
they are slightly tapering with the finishing line
ending in a smooth feather edge and placed just below
the level of the free gingival tissue.
Sharp line angles should be smoothed to ensure that
the crown does not bind on seating.
Radcliffe and Cullen recommended preparation of
proximal slices but no preparation of the buccal or
lingual tooth walls. This procedure allows the extra
option of future placement of an onlay, rather than
only a full coverage crown.
68. Crown modification for permanent
molar PMCs
The selected crown should establish a good contact
area with neighboring teeth and snap into place
cervically. If required, the crown margin can be
trimmed with crown scissors .
The crown gains its retention from the cervical margin
area so the crown margin must be recrimped after any
adjustments to ensure an accurate fit to the tooth.
Specialized crimping pliers are available for this
purpose and crown-contouring pliers can be used to
improve interproximal contact area morphology and
to modify the gingival margin contour
71. Initial seating of the crown
The crown is tried on the tooth 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.
72. CROWN ADAPTATION
Try crown on tooth : lingual to buccal
Mark scratch line
Cut 1 mm below it with scissors
Place the crown again : If blanching seen : rescribe &
retrim
If doesn’t seat completely : reduce occlusal surface
73. Spedding’s Adaptation principle – 1
Crown length
Any point on tooth occlusal to greatest diameter is on
the visible clinical crown, and any point on the tooth
apical to greatest diameter is on an undercut surface of
tooth and is not visible
74. 1 ) View from proximal surface ; buccal –lingual
surfaces converge occlusally.
2) Any point above greatest diameter ; visible
clinically
3) Any point below greatest diameter ; not visible
clincally
75. Spedding’s Adaptation principle -
2
Correct contours of buccal and lingual gingival
marginns of crown to gingival tissues
Margins apical to the greatest diameter ; good
adaptation
77. Crown Trimming
If the crown is excessively long, the crown margin may
impede complete seating, in which case crown length
may be adjusted by trimming with crown shears and
resmoothing and polishing the edges with an abrasive
stone.
Over trimming of the crown margin should be
avoided, as this may affect retention if it results in
reduced adaptation of the crown margin into undercut
areas.
78. Crown Trimming
It is essential that the margins of the crown are well
adapted into undercut areas, which is usually achieved
by crimping of the crown edges.
Special attention should be given to adaptation of the
distal margin on second primary molars where the
permanent molar is unerupted. An uncorrected distal
overhang may result in impaction of the first
permanent molar.
Care should be taken not to cause iatrogenic damage
to adjacent teeth or unerupted teeth.
79. Crown Trimming
Frequently, reduction in the mesio-distal dimension of
the crown will be necessary, especially where mesial
drift (often due to caries) has resulted in loss of arch
length.
Moderate reduction in mesio-distal dimension can be
achieved by flattening of the mesial and distal contact
areas of the crown with Adam’s pattern pliers.
Where mesial drift has occurred in the lower arch it
may be possible to use a SSC form for the contralateral
upper tooth (e.g. ULE crown form for LRE) as these
SSC forms have a shorter mesiodistal dimension
80. Contouring pliers used
No 112 Ball & Socket Plier
No 137 Gordan plier
No 114 Johnson plier ,
Used for initial contouring in middle third
81. Crown contouring
The crown is contoured using a Ball and Socket
pllier(No:114) at the junction of middle & cervical third
of the crown with concave surface held outwards to
ensure good fit.
82. Crown contouring
Gingival Contours
Buccal gingival contour of E : Smile
Buccal gingival contour of D : Stretchout ‘S’
Proximal contour of primary molars : Frown
Lingual contours of all primary molars : Smile
83. Crimping
The Crimping of the crown is done using crimping
pllier (No:417) to adapt the cervical margins of the
crown inwards.
Johnson’s contouring pllier (No:113) can also be used.
84. CROWN CRIMPING
Evaluation;- Check with explorer
If margins open : recrimp
If overextended : start again
Blanching : Johnson 1987
Bitewing radiograph : More&Pink 1973
Incorrect seated sscCorrect seated
86. Final adaptation of the crown:
1) Crown must snap into place, should not be able to
be removed with finger pressure.
2) The crown should fit so tightly that there is no
rocking on the tooth.
3) Moderate occlusal displacement forces at the
margin should not displace the crown.
4)The properly seated crown will correspond to the
marginal height of the adjacent tooth and is not
rotated on the tooth.
87. Final adaptation of the crown
5)Crown is in proper occlusion and should not
interface with the eruption of teeth.
6)There should be no high points when checked with
an articulating paper.
7)The crown margin extends about 1mm gingiva to
gingival crest.
8) No opening exists between the crown and the tooth
at the cervical margins.
88. Final adaptation of the crown
9)Crown margins closely adapted to the tooth and
should not cause gingival irritation.
10)Restoration enables the patient to maintain oral
hygiene.
11)The crown seats without cutting or blanching the
gingiva.
89. FINISHING
It is safe to say that retention problems do not cause
failure of the steel restoration;
most failures result from poor and inadequate
preparation, improper gingival adaptation, and the
inability to properly visualize and determine the
relationship of the crown margin to the margin of the
preparation.
90. POLISHING
While polishing the crown, margins should be blunt since
knife edge finish produces sharp ends which act as areas of
plaque retention.
A broad stone wheel should run slowly, in light brushing
strokes, across the margins, towards the center of the
crown.
This will draw the metal closer to the tooth without
reducing the crown height and thus improves the
adaptation of the crown.
A wire brush can be used to polish the margins to a high
shine. To give a fine Luster to crown, rough whiting or a
fine polishing material can be used.
91.
92. CROWN FIT
Spedding (1984) observed that most stainless crowns
seemed acceptable when observed clinically.
If there is any doubt about the fit of the crown, a
radiograph may be taken after cementation; however
routine radiographs of all patients to determine the fit
of all stainless steel crowns are not justified.
93. CEMENTATION
Among all the cements used for cementation, the GIC
was found quiet new & very promising.
Glass ionomer cements are quite new and very
promising. These cements have comparable strengths
with zinc phosphate, release fluoride as do the
silicophosphate, chelate or bond to tooth structure as
the polycarboxylate and are as pulpally compatible as
the polycarboxylates.
They could prove to be the best cement available for
steel crown cementation.
94. There is, however, some evidence suggesting that the
specific choice of cement does not significantly affect
retention, the most important retentive components
being derived from correct contouring and crimping of
the crown.
95. Steps for cementation
Stainless steel crown should be cemented only on clean,
dry tooth. Isolation of teeth with cotton rolls is
recommended. Apply Vaseline to contact areas.
Rinse and dry the crown inside and outside and prepare to
cement it. ZnPO4, Polycarboxylate, or GIC are preferred.
If ZnPO4 is used, 2 coats of cavity varnish should be applied
on vital tooth before cementation and cement should be of
consistency so that it stings about 1½ inches from mixing
pad with the spatula cement is filled in approximately 2/3rd
of crown, with all inner surface covered.
96. Seat the crown completely on dried tooth surface
preparation. Final placement should follow an
established path of insertion of the crown. Cement
should be expressed around all margins. To ensure
complete seating of the crown, handle of mirror or
band pusher may be used.
Before the cement sets, ask the patient to close into
centric occlusion by applying pressure through a
cotton roll and confirm that the occlusion has not
been altered.
97. ZnPo4 cement can be easily removed with an explorer
or scaler. After the polycarboxylate cement is partially
set, it will reach a rubbery consistency. Excess cement
should be removed at this stage with explorer tip.
Rinse the oral cavity and before dismissing the patient,
reexamine the occlusion and the soft tissue.
98.
99. Careful attention should be paid to removal of excess
cement. This can usually be effectively achieved by
running a pointed instrument around the margins of
the cemented crown and by passing knotted dental
floss bucco-lingually through the contact areas prior to
the cement setting.
Excess cement has been shown to be detrimental to
gingival health.
100. Hall technique
The Hall Technique is a non invasive treatment for
decayed molars teeth. Decay is sealed under
preformed , avoiding injections and drilling. It is one
of a number of biologically orientated strategies for
managing caries
A General dental practitioner from Scotland, who
developed and used the technique for over 15 years
until she retired in 2006
101. Hall technique
PROCEDURE
The Halls technique requires several appointments for
time intervals to occur, to allow separation of the
teeth, placement.
the efficacy of the Hall’s technique in the management
of carious primary molars with caries extending only
to dentine.
102.
103.
104. MODIFICATIONS OF STAINLESS
STEEL CROWN
In 1971 Mink and Hill reported several ways of modification of
stainless steel crown when the crowns are either too large or too
short.
Undersized tooth or the oversized crown:
This commonly occurs when, due to a long-standing
interproximal caries, space loss has occurred. To reduce the
crown circumference, a V cut is made up of the buccal surface to
the occlusal surface.
The cut edges are reapproximated to overlap one another making
the crown circumference smaller. The crown is tried on the tooth
and amount of overlapping necessary is marked on the crown.
The overlapped edges are then spot-welded.
The crown is polished with a rubber wheel and fine abrasives.
105.
106. Oversized tooth or the undersized crown:
Separate the edges as needed and weld a piece of
0.004inch orthodontic band material across the cut
surface. After contouring, apply the solder to fill any
microscopic deficiency in seal, polish the soldered
crown.
107.
108. Deep sub gingival caries:
Complete the indicated pulp treatment and then
restore the cavity preparation.
If subgingival caries occurs interproximally, the
unfestooned crown will be deep enough to cover
the preparation.
109. Open contact:
If the closed contact area (except for the primate
spaces) is not established, it will result in food
packing, increased plaque retention and subsequently
gingivitis.
This problem can be solved by selection of a larger
crown or exaggerated interproximal contour can be
obtained with a 112 (ball and socket) plier to establish a
close contact. Interproximal contour can also be build
by addition of a solder.
110.
111. Open faced stainless crowns:
The SSCs can be modified in anterior teeth by a open
faced SSC, which is simply a SSC with the labial
surface trimmed away & restored with a resin
veneering (Croll, 1998)
112. SPECIAL CONSIDERATIONS FOR
STAINLESS STEEL CROWN
A) Quadrant Dentistry:
When the quadrant dentistry is practiced, stainless
steel crowns are to be placed on adjacent teeth. Few
points, which are to be considered here are (Nash
1981).
Prepare the occlusal reduction of one tooth completely
before beginning the occlusal reduction of the other
tooth because there is tendency to under reduce both,
when reduction on both the teeth is done
simultaneously.
113. When two adjacent crowns have to be placed reduce
the adjacent proximal surface of the teeth being
restored more. The greater reduction will ease the
placement of the crowns and interproximal
approximation.
Both crown should be trimmed, contoured, and
prepared for cementation simultaneously to allow for
adjustments in the interproximal spaces and establish
proper contact areas.
To get these adjustments, adapt and seat the crown on
the most distal tooth first and proceed mesially.
114.
115. B) Crowns in areas of space loss (Mc Evoy 1977)
When there is an extensive and long standing caries,
the primary teeth shift into the interproximal contact areas.
As a result, the crown required to fit over the buccolingual
dimensions will be too wide than mesiodistal to be placed
and the crown selected to fit over mesiodistal space will be
too small in circumference.
Select larger crown, which will fit over the tooth's greatest
convexity.
Reduce the mesiodistal width by grasping the marginal
ridges of the crown with Howe utility pliers and squeezing
the crown.
116. Recontour the proximal, buccal, and lingual walls of
the crown with the No. 137 or No. 114 pliers.
Do the additional reduction of buccal and lingual
surface of tooth and select a smaller crown, if this
crown is difficult to place.
117. Orthodontic bands
When cementing orthodontic bands to stainless steel
crowns roughening of the internal surface of the band
and external surface of the crown prior to cementation
has been shown to improve retention.
118. COMPLICATIONS
Interproximal ledge:
A ledge will be produced instead of a shoulder free
interproximal slice, if the angulation of the tapered fissure
bur is incorrect. Failure to remove this ledge will result in
difficulty in seating the crown.
When the adjacent tooth is partially erupted, and the
contact is poorly established, the interproximal slice is
difficult to prepare. To clean the contact area, extensive
subgingival tooth reduction is required which may result in
formation of a ledge or damaging the erupting tooth. In
such a case, it may use to delay crowning until contact
areas are properly established.
119. Crown tilt:
Complete lingual or buccal wall may be destructed by
caries or improper use of cutting instruments. This
may result in finished crown tilting towards the
deficient side. Placement of restoration prior to
crowning provides a support to prevent crown tilt, the
alloy as core. The clinical significance of crown tilting
is minimal unless it occurs on young permanent
molars, where supra-eruption of the opponent tooth
may occur.
120. Poor margins:
When the crown is poorly adapted, its marginal
integrity is reduced. Recurrent caries may occur
around open margins, chances of plaque retention and
subsequently gingivitis increases with marginal
discrepancy
Aesthetics :
Parents complain about the appearance .
In this case a mesiobuccal facing can be placed after the
crown has been cemented into place {Robert 1983}
121. Inhalation or Ingestion of crown:
To prevent such mishaps, the rubber dam should remain in
place until cementation. It prevents accidental swallowing
or aspiration of a crown. Sometimes sudden movement
may result in ingestion of the crown, if the rubber dam is
not used. In this regard, floss attachment by means of
impression compound on the occlusal of the crown is the
preferred practice by some clinicians.
If the crown is in bronchi or lung, medical consultation will
probably result in attempt to remove it by bronchoscopy.
122. The presence of cough reflex in the conscious child
will reduce the chances of inhalation and ingestion of
the crown is more likely. Ingestion is of less
consequence, as the crown will usually pass
uneventfully through the alimentary tract within 5-10
days. But it should be diagnosed by absence of the
crown on a chest radiograph.
123. Occlusal wear:
Children with tooth grinding habits may exhibit wear
through existing SSC. When this wear 0ccurs the
crown should be replaced. If the wear is confined to a
small area on the tip of a cusp then a small amalgam
restoration can be placed in the hole in the wear facet,
so as to preclude the cement dissolving away and
leaving a defect.
128. CONCLUSION
The judicious combination of one of the various tooth
preparation techniques mentioned by various research
workers and proper manipulation of metal crown in
skillful hands, along with continuous improvements
which have been made in the anatomic configuration
of the crown, would lead to a wonderful restoration
with high durability.
129. REFERENCES
Kennedy’s Pediatric Operative Dentistry_ Curzon,
kennedy DB, Roberts
Fundamentals of Pediatric Dentistry_ Richard.
Mathewson
Dentistry for child and adolescent_ Ralphe Mc
Donald, Avery.
Clinical Pedodontics_ Sidney B Finn
Pediatric dentistry-Infancy through adolescence_
Pinkam
Text Book Of Pedodontics_ Shobha Tandon.
130. M memarpour ,D Reza M Razavi Comparison of
microleakage from stainless steel crowns margins used
with different restorative materials: An in vitro studyDent
Res J 2016 Jan-Feb; 13(1): 7–12.
Shah, Purvi V.; Lee, Jessica Y.; Wright;(2004) Clinical
Success and Parental Satisfaction With Anterior
Preveneered Primary Stainless Steel Crowns Pediatric
Dentistry, Volume 26, . 391-395(5).
Preformed metal crowns for primary and permanent molar
teeth: REVIEW of the Literature_ Ros C Randall. Pediatric
dentistry, 24; 5:2002, pg489.
Efficacy of preformed metal crowns Vs amalgam
restorations in primary molars. A systemic Review. JADA,
131:337-440; march2000.
