This document provides an overview of stainless steel crowns for pediatric dentistry. It discusses the history, composition, indications, contraindications, advantages and disadvantages of stainless steel crowns. It describes different types of crowns based on composition and morphology. The document outlines the armamentarium, techniques, adaptations and modifications for stainless steel crowns. It is intended to serve as a reference for using stainless steel crowns in treating pediatric dental patients.
4. INTRODUCTION
Maintenance of the primary dentition in a healthy condition is important for the
overall well being of the child.
Treatment of the severely destructed teeth poses a challenge for the pediatric
dentist as 3 important FACTORS have to be kept in mind,
1. Patient’s behavioural management,
2. Preservation of the tooth structure and
3. Parental satisfaction.
5. The technological advances in dental materials in children make constant re
evaluation of our treatment philosophies and techniques a necessity because
what was an acceptable treatment approach in the past may not necessarily
be the best treatment option for our young patients today.
Dental decay in children’s teeth is a significant public health problem, affecting
60% to 90% of school children in industrialized countries (WHO Report 2003)
INTRODUCTION…
6. Many options exist to repair carious teeth in paediatric patients, from
stainless steel crowns to its various modifications to other esthetic crowns like
strip crowns and zirconium crowns which are rising in their popularity.
INTRODUCTION…
7. STAINLESS STEEL CROWNS (SSCS)
A crown is a tooth shaped covering which is cemented to the tooth structure & its main
function is to protect the tooth structure & retain the function
7
8. STAINLESS STEEL CROWNS
The preformed metal crown (PMC), more commonly known as the stainless
steel crown (SSC), has been used for approximately 50 years.
Preformed metal crowns (PMCs) for primary molar teeth were first described
in 1950 by Engel, followed by Humphrey.
9. THE SSC STORY…!!
Dr. William Humphrey of Denver,
Colorado.
Relation with Rocky Mountain
Orthodontic company.
10. It began as a fairly crude metal tube closed on one end with a prestamped
facsimile of a molar occlusal surface.
It required a significant amount of time and skill to trim, festoon, crimp and
harden the margins to custom fit the tooth.
Today’s crown is much easier to place and often requires minimal
modifications from its manufactured form.
THE SSC STORY…!!
11. CLASSIFICATION: BASED ON COMPOSITION
1. Stainless Steel crown ( Unitek and Rocky Mountain crowns)
2. Nickel-Base crowns (Ion Ni-chro from 3M)
3. Tin –base crowns
4. Aluminum -base crowns
12. COMPOSITION
Iron (67%), carbon, chromium (17-19%), nickel (10-13%), manganese and
other metals (4%).
Chromium oxidizes - “passivating film”
The term “stainless steel” is used when the chromium content exceeds 11%
and is generally in the range of 12 to 30%.
SSC contain about 18% chromium and 8% nickel as well as small amounts of
other elements and are considered as 18-8 stainless steel.
13. Composition
Stainless steel crowns (18-
8) Austenitic type (Rocky
mountain)
• 17-19%chromium
• 10-13% nickel
• 67% iron
• 4% minor elements
Nickel base crowns
(InConell 600 alloy)
• 72% nickel
• 14% chromium
• 6-10% iron
• 0.04% carbon
• 0.35% manganese
• 0.2% silicon
13
14. Manufacturer Iron Chromium Nickel Carbon,
Manganese,
Silicon
Unitek 67 17 12 4
3M 10 16 72 2
Chemical Composition of Two types of Crowns Expressed as Percentages
Brook & King. Dent Update 9:25, 1985. 14
15. CLASSIFICATION: BASED ON MORPHOLOGY
According to form and contour:
1. Uncontoured/ untrimmed crowns
(Rocky mountain, Unitek)
2. Pretrimmed crowns
(Unitek stainless steel crowns,3M,De novo crowns)
3. Precontoured crowns
( Ni-chro ion crowns 3m Crowns and Unitek)
16. Classification
16
Untrimmed crowns (e.g. Rocky
Mountain)
• neither trimmed nor contoured
• longer
• lot of adaptation
• time consuming
Pre trimmed crowns (e.g. Unitek
stainless steel crowns, 3M and
Denovo crowns)
• straight, non-contoured sides
• but shorter
• festooned
• require contouring
17. Pre contoured crowns (e.g.
Ni-Cr Ion crowns , Unitek
stainless steel crowns,3M)
• Festooned, Pre Contoured & Pre
trimmed
• minimal amount of adjustment
necessary
• more difficulty in adaptation since
trimming will result in removal of
manufacturers gingival crimp
Preveneered SSC
• Aesthetic posterior crowns
• Resin based composite bonded
to the buccal and occlusal
surfaces
• Allow only minimal crimping
17
18. AUSTENITIC V/S FERRITIC
Increased ductility and ability to be cold worked without fracturing
Strengthening during cold working
Greater ease of welding
Ability to overcome sensitization (> 6500C)
18
19. INDICATIONS FOR USE IN PRIMARY MOLAR TEETH
1. After pulp therapy;
2. Multisurface caries
3. Pt’s at high caries risk;
4. Where a restoration is likely to fail (eg, proximal box Extended beyond the
anatomic line angles;
5. Fractured teeth;
6. Teeth with extensive wear (bruxism);
7. Abutment for space maintainer.
20. INDICATIONS FOR PERMANENT MOLAR TEETH
1.Interim restoration of a broken-down or traumatized tooth
2. When financial considerations are a concern,
3. Teeth with developmental defects (dentin dysplasia, sensitivity).
4. Restoration of a permanent molar which requires full Coverage but is
only partially erupted.
21. INDICATIONS
1.Restoration of carious primary molars where more than two surfaces are
affected, or where one or two surface carious lesions are extensive.
2.If restoration is needed to last >2 yrs
21
22. 3. Child < 6yrs SS crown preferable to restorations
4. Following pulpotomy or pulpectomy procedures. (Kindelan 2008)
22
INDICATIONS
23. 23
5.Localized or generalized developmental problems,
e.g.:Enamel hypoplasia,
Amelogenesis imperfecta,
Dentinogenesis imperfecta
6. Restoration of fractured primary molars.
INDICATIONS
24. 24
7. Extensive tooth surface loss due to
Eg : Attrition
: Abrasion/erosion
: Bruxism
8. In patients with a
high caries susceptibility
9. As an abutment for certain
appliances, such as
space maintainers.
INDICATIONS
25. 25
10. In patients where routine oral hygiene measures are
impaired.
11.In patients undergoing restorative care under general
anaesthesia if two or more surfaces are involved
12. In patients with infra-occluded primary molars
13. Single tooth cross bite
INDICATIONS…
26. 26
14. As an “emergency” measure to reduce the sensitivity of these
teeth
15. For :temporary restoration of permanent teeth
:fractured permanent anterior teeth and
:young permanent molars following endodontic treatment.
16. Recurrent caries around existing restorations
INDICATIONS…
27. CONTRAINDICATIONS
1. Non restorable and severely broken down teeth
2. As a permanent restoration in a permanent teeth
3. Primary teeth exhibiting more than ½ of root resorption
4. If the primary molar is close to exfoliation with more than half the roots resorbed or exfoliation within 6-
12 months
5. Clinical or radiographical evidence of radicular pathology
6. Tooth exhibits excessive mobility
27
28. CONTRAINDICATIONS
6. Primary posterior teeth - conservative restorations can be placed
7. Partially erupted teeth
8. Esthetically unappealing
9. Where conservative restorations can be placed
10. In a patient with a known nickel allergy or sensitivity
-ESPE SSC consists of a chromium-nickel
steel of surgical quality.
- Incidence of Ni allergy due to orthodontic
treatment 1 in 100 (Hensten& Petersen 1992)
-Conventional SS crowns do not aggravate hypersensitivity (Janson 1998) 28
29. ADVANTAGES
1. Their lifespan is the same as that of an intact primary tooth.
2. They provide protection to the residual tooth structure that may have been
weakened after excessive caries removal.
3. The technique sensitivity or the risk of making errors during their application
is low.
4. Their long-term cost effectiveness is good.
5. They have a low failure rate.
31. SIZE FOR SSC TOOTH SIZES AVAILABLE WIDTH RANGE
(MM)
Upper 1st primary molar 2- 7 7.2 to 9.2
Upper 2nd primary molar 2-7 9.2 to 11.2
Lower 1st primary molar 2-7 7.4 to 9.4
Lower 2nd primary molar 2-7 9.4 to 11.4
Upper 1st permanent molar 2-7 10.7 to 12.8
Lower 1st permanent molar 2-7 10.8 to 12.8
Sizes 4 & 5 are most often
used
Supplied in kit form with
user
needing to reorder only
those
sizes frequently used.
39. PLIER NAME NO. OF
PLIER
USE
Gordon plier no 137 Contouring gingival third of crown
Ball & socket plier no 112 Exaggerating interproximal contour in
open contacts, for bell shaped contouring
Howe plier no 110 Flattening interproximal contour of crown
Howe Plier
40. OTHERS:
•Rough or whitening polish wheels.
•Sharp scalers or instruments
•Cement medium
-Glass slab
- Spatula/ Agate spatula
- Luting cement
•Dental floss
•Rubber dam armamentarium
•Sharp explorer- for marking gingival extension of crown margin
41. TECHNIQUE
1. Evaluate the preoperative occlusion:
2. Selection of crown
3. Tooth preparation
1. Anterior
2. Posterior
4. Final adaptation of the crown
5. Finishing
6. Polishing
7. Crown fit
8. Cementation
42. Crown selection
Determine the mesiodistal width of the crown from premeasured chart or measure it using boley
gauge or vernier calipers.
STEPS FOR CLINICAL PROCEDURE
43. STEPS
Pre-operative occlusion evaluation
By visual examination and transfer this relation on
the wax-sheet by asking the patient to bite.
Local anaesthesia administration.
As minimal amount of gingival tissue is
manipulated during crown cutting.
Caries removal
Occlusal reduction -1.5 -2mm (Keneddy)
44. Rubberdam application.
Placement of wedges.
They are placed in interproximal space
which act as tooth seprators and also
protects the underlying soft tissues.
45. Tooth preparation.
Occlusal reduction
Uniform occlusal reduction of 1.0- 1.5 mm which
follows the anatomy of occlusal surface.
46. FOR TOOTH REDUCTION:
Occlusal reduction
Uniform occlusal reduction of 1 to 1.5mm using a 1mm bur to make grooves in the occlusal surface
to guide the reduction.
Proximal reduction
Tapered fissure bur is used to reduce the trauma to soft tissues.
Bur is moved buccolingual direction starting at the occlusal surface 1-2 mm away from occlusal
surface.
Mesial and distal clearance and a smooth taper obtained free of ledges and shoulders.
Buccal and lingual reduction
Minimal reduction is necessary.
Line angles rounded
47. Trial fitting, trimming and contouring the crown.
To leave the crown margins in the gingival sulcus.
To reproduce tooth morphology.
Finishing the crown.
It is done with stone and rubber wheel to remove scratches.
48. 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 if required
are reduced at least 0.5 mm which the reduction ending in a feather edge 0.5
to 1mm into the gingival sulcus.
49. 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.
50. ADAPTATION OF CROWN
Initial adaptation of crown
Two principles of Spedding (1984)
Correct occluso-gingival crown length
Crown margins should follow tooth’s marginal gingiva
51. A. Gingival contour of 2nd molar- ‘smile’
B. Gingival contour of 1st molar –
‘stretched s’
C.Proximal gingival contour of molars –
‘frown’
52. Seat the lingual side first
Friction should be felt
Gingival blanching- long crown
Crown does not seat-
- Inadequate occlusal reduction
- Proximal ledge
- Contact not broken
SEATING THE CROWN
53. CONTOURING THE CROWN
Johnson 114 plier (ball and socket pliers)
Middle 1/3rd of crown-belling effect.
Dentarum 112 plier (Abell plier)-proximal surface.
137 Gordan pliers- gingival 1/3rd of crown.
54. Unitek 800-412 pliers
Groper crimper #230-750
Tight marginal fit aids in
- Mechanical retention of the crown
- Protection of the cement from exposure to oral fluids
- Maintenance of gingival health
CROWN CRIMPING
55. Final Adaptation Of The Crown:
Crown must snap into place, should not be able to be removed with finger
pressure.
The crown should fit so that there is no rocking on the tooth.
Moderate occlusal displacement forces at the margin should not displace the
crown.
The properly seated crown will correspond to the marginal height of the
adjacent tooth and is not rotated on the tooth.
56. Crown is in proper occlusion and should not interface with the eruption of teeth.
There should be no high points when checked with an articulating paper.
The crown margin extends about 1mm gingiva to gingival crest.
57. No opening exists between the crown and the tooth at the cervical
margins.
Crown margins closely adapted to the tooth and should not cause
gingival irritation.
The crown seats without cutting or blanching the gingiva.
58. TITLE Comparison of Marginal Circumference of Two Different Pre-crimped Stainless Steel
Crowns for Primary Molars After Re-crimping
AUTHORS
JOURNAL
Hossein Afshar, Mehdi Ghandehari, Banafsheh Soleimani
Journal of Dentistry, Iran 2015. LEVEL: 4
AIM To assess the changes in the circumference of 3M ESPE and MIB pre-crimped stainless
steel crowns (SSCs) for primary maxillary and mandibular first and second molars following
re-crimping
METHOD Initial photographs were obtained from the margins of 3M and MIB SSCs for the upper and
lower primary molars using a digital camera. Crown margins were crimped by applying 0.2N
force using 114 and
137 pliers. Post-crimping photographs were also obtained and the changes in crown
circumference after crimping were calculated using AutoCad software. The percentage of
reduction in the circumference of crowns for each tooth was statistically analyzed. The effect
of crown design and the associated teeth on the decreased circumference percentage was
statistically analyzed.
59. CONCLUSION Considering the significant reduction in the marginal circumference of precrimped
SSCs following re-crimping, it appears that this manipulation must be necessarily
performed for MIB and 3M pre-crimped SSCs. By using 3M SSCs, higher marginal
adaptation can be achieved following crimping.
RESULT The percentage of reduction in lower E SSC circumference was 3.71±0.39% in MIB and
6.29±0.62% in 3M crowns. These values were 3.55±0.55% and 7.15±1.13% for the lower
Ds, and 3.95±0.43 and 6.24±0.85% for the upper Ds, respectively. For the upper Es,
these values were found to be 3.12±0.65% and 5.14±0.94%, respectively. For each
tooth, a significant difference was found between MIB and 3M SSCs in terms of the
percentage of reduction in crown circumference following crimping. The magnitude of
this reduction was smaller in MIB compared to 3M SSCs (P<0.001).
60. Finishing and 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.
61. Radiographic Confirmation of Gingival Fit
Crown too long-reduce the length.
Crown short- orthodontic band or adaptation of another crown.
62. CEMENTATION
Rinse and dry the crown.
Cements used are ZnOE, ZnPO4,
Polycarboxylate, glassionomer
cement, self curing resin-RMGI
preferable
When the cement is half set , the
occlusion is rechecked
Excess cement should be removed
using explorer tip, dental floss.
63. POST CEMENTATION INSTRUCTION
Avoid heavy chewing with the crown for 24 hours.
Maintain oral hygiene.
Recalled after 6 months.
64. Interproximal ledge.
Crown tilt.
Poor margins.
Inhalation or ingestion of crown.
Under extension of crown.
Over extension of crown.
COMPLICATIONS
65. The gingival finishing line should be a feather edge.
A taper mesially and distally will help to achieve this.
The Buccal and Lingual surfaces if required are reduced 0.5mm, with the
reduction ending in a featheredge, 0.5 to 1mm into the gingival sulcus
68. ADJACENT CROWNS (DAVID NASH, 1981)
When restoring multiple primary molars in the same quadrant, it is advisable to
reduce the adjacent proximal surface of the teeth being restored more than
when only one tooth is restored.
The greater reduction will ease the placement of crowns and the interproximal
approximation.
The more severe tooth reduction is necessitated by the loss of arch
circumference, which occurs when the proximal surfaces of two adjacent teeth
are affected. 7/9/2019 68
MATHEWSON.: FUNDAMENTAL OF PEDIATRIC DENTISTRY. 3RD ED. QUINTESSENCE PUBLISHING CO. SHICAGO, 1995
69. ADJACENT TO CLASS II AMALGAM (MC EVOY, 1985)
First crown reduction is completed and crown is adapted.
Cementation of crown.
Next do amalgam restoration with matrix band in place.
Remove the matrix band.
Final carving of amalgam.
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MATHEWSON.: FUNDAMENTAL OF PEDIATRIC DENTISTRY. 3RD ED. QUINTESSENCE PUBLISHING CO. SHICAGO, 1995
69
70. INAPPROPRIATE SIZE OF CROWN AVAILABLE
In 1971 Mink and Hill reported several ways of modification of stainless steel crown when the crowns
are either too large or too short.
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MATHEWSON.: FUNDAMENTAL OF PEDIATRIC DENTISTRY. 3RD ED. QUINTESSENCE PUBLISHING CO. SHICAGO, 1995
70
71. OVERSIZED
CROWN
7/9/2019 71
MATHEWSON.: FUNDAMENTAL OF PEDIATRIC DENTISTRY. 3RD ED. QUINTESSENCE PUBLISHING CO.
SHICAGO, 1995
Check the crown for marginal adaptation, contour,
crimp and the cement the crown
Polish the soldered area
The cut edges can then be repositioned and spot-
welded
Again try the crown on the tooth
Pinch the crown together in effect reducing the
crown size
Use a pair of scissors to cut the crown from the
gingival to the occlusal surface, either buccally or
lingually
Try the crown on the tooth
72. UNDERSIZED
CROWN
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MATHEWSON.: FUNDAMENTAL OF PEDIATRIC DENTISTRY. 3RD
ED. QUINTESSENCE PUBLISHING CO. SHICAGO, 1995Polish the soldered area and cement the crown
solder, adapt, contour and crimp the crown
Retry the crown on the tooth
Spot weld a strip of orthodontic band material over
the v shaped groove in the crown
Try the crown on the tooth for fit
Cut a v shaped groove in the crown on the buccal
or lingual side
Check the crown on the tooth
73. DEEP PROXIMAL LESIONS
Solder and polish the area and cement the crown
Spot weld the piece to crown and check the
adaptation and extent
Cut a piece of orthodontics band conforming to the
lesion
Prepare the crown for the tooth
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MATHEWSON.: FUNDAMENTAL OF PEDIATRIC DENTISTRY. 3RD
ED. QUINTESSENCE PUBLISHING CO. SHICAGO, 1995
73
74. CROLL MODIFICATION
Patients with tooth grinding habits may tend to wear through the occlusal
surfaces of stainless steel crowns.
A technique is described which prevents this problem by increasing metal
occlusal surface thickness of the crown.
7/9/2019 74
75. HALLS TECHNIQUE
It is a novel method of managing carious primary molars by cementing
preformed metal crowns over them.
The technique does not require local anesthesia, caries removal or any tooth
preparation.
It requires careful case selection, a high level of clinical skill, and excellent
patient management
7/9/2019
INNES, N.P.T., STIRRUPS, D.R., EVANS, D.J.P., HALL, N. AND LEGGATE, M., 2006. A NOVEL
TECHNIQUE USING PREFORMED METAL CROWNS FOR MANAGING CARIOUS PRIMARY
MOLARS IN GENERAL PRACTICE – A RETROSPECTIVE ANALYSIS. BRITISH DENTAL JOURNAL,
200(8), PP. 451-454.
75
76. The technique is named after Dr Norna Hall, a general dental practitioner
from Scotland, who developed and used the technique for over 15 years
until she retired in 2006.
With the Hall Technique, the process of fitting the crown is quick and
non-invasive.
7/9/2019
INNES, N.P.T., STIRRUPS, D.R., EVANS, D.J.P., HALL, N. AND LEGGATE, M., 2006. A NOVEL TECHNIQUE USING
PREFORMED METAL CROWNS FOR MANAGING CARIOUS PRIMARY MOLARS IN GENERAL PRACTICE – A
RETROSPECTIVE ANALYSIS. BRITISH DENTAL JOURNAL, 200(8), PP. 451-454.
76
77.
78. INDICATIONS OF HALLS TECHNIQUE :
Class I lesions, non-cavitated
if patient unable to accept fissure sealant, or conventional restoration
Class I lesions, cavitated
if patient unable to accept partial caries removal technique, or conventional
restoration
Class II lesions, cavitated or non-cavitated
79. CONTRAINDICATIONS FOR FITTING HALL CROWNS
Irreversible pulpal involvement
Insufficient sound tissue left to retain the crown
Patient co-operation where the clinician cannot be confident that the crown
can be fitted without endangering the patient’s airway
A patient at risk from bacterial endocarditis.
Parent or child unhappy with aesthetics.
80. TITLE The success of stainless steel crowns placed with the Hall technique: a retrospective
study.
AUTHOR
LEVEL OF EVIDENCE
J Am Dent Assoc. 2014 Dec;145(12):1248-53.
Ludwig KH, Fontana M, Vinson LA, Platt JA, Dean JA
Ic
AIM In this retrospective study, the authors evaluated the clinical and radiographic success of stainless steel
crowns (SSCs) used to restore primary molars with caries lesions, placed by means of both the
traditional technique (involving complete caries removal and tooth reduction before placement of the
SSC) and the Hall technique (involving no caries removal, no crown preparation and no use of local
anesthetic before placement of the SSC).
MATERIALS AND METHOD The authors conducted a retrospective chart review by using the patient records at a
private pediatric dental practice at which the Hall technique had been introduced in June 2010 as an
alternative treatment to traditional SSC placement. The inclusion criteria were caries lesions on a primary
molar with no clinical or radiographic evidence of pulpitis, necrosis or abscess, as well as follow-up of at
least six months or until failure, whichever came first. They graded restoration success by using a four-
point scale based on presence or loss of the SSC, and whether or not the patient needed further
treatment associated with pulpal pathology or secondary caries. They collected and summarized patient
demographic information. They used a Kaplan-Meier survival curve along with 95 percent confidence
intervals to evaluate clinical success.
81. RESULT The authors found that 65 (97 percent) of 67 SSCs placed with
the Hall technique (mean observation time, 15 months; range, four-37 months) and
110 (94 percent) of 117 SSCs placed with the traditional technique (mean observation
time, 53 months; range, four-119 months) were successful.
CONCLUSION Findings of this study show a similar success rate for SSCs placed with the
traditional technique or the Hall technique.
82. TITLE The use of stainless steel crowns: a systematic literature review.
AUTHORS
LEVEL OF EVIDENCE
Pediatr Dent. 2015 Mar-Apr;37(2):145-60
Seale NS, Randall R
Ia
AIM The purpose was to review the published literature on stainless steel crowns (SSCs) from 2002 to the
present as an update to an earlier review published in 2002
METHOD Included were published papers on clinical studies, case series, and laboratory testing on SSCs
(including esthetic SSCs and the Hall technique) in peer-reviewed journals. Study quality and strength of
evidence presented were assessed for papers reporting clinical results for SSCs as a primary study
outcome using a list of weighting criteria.
RESULT Sixty-one papers fulfilled the inclusion criteria (24 papers on 22 clinical studies, three case reports, 21
reviews and surveys, and 13 laboratory testing reports on SSCs and esthetic preformed
metal crowns for primary and permanent molar teeth). Ten clinical studies achieved weighting scores
ranging from 68 percent to 26 percent, with the two highest scoring studies (68 percent and 63 percent)
considered good quality.
CONCLUSION Within the confines of the studies reviewed, primary molar esthetic crowns and SSCs had superior
clinical performance as restoratives for posterior primary teeth, and the Hall technique was shown to
have validity. No clinical studies were available on zirconia crowns. Further well-designed prospective
studies on primary molar esthetic crowns and the Hall technique are needed.
83. B
TITLE A randomized clinical trial investigating the performance of two commercially available posterior pediatric
preveneered stainless steel crowns: a continuation study.
AUTHOR
LEVEL OF EVIDENCE
Kratunova E1, O'Connell AC2
Pediatr Dent. 2014 Nov-Dec;36(7):494-8
Ib
AIM This study aimed to compare the clinical and radiographic success of preveneered posterior NuSmile® and Kinder
Krowns® over one year and to assess the level of parental satisfaction with their esthetics.
METHOD Three trained operators placed 120 crowns in a split-mouth design with a random allocation for 36 participants
(mean age: 5.8 years) who received two, four, six, or eight crowns. Blind assessment of the clinical and
radiographic performance of the restorations was performed by four calibrated examiners after one year. Results
were analyzed by Fisher's exact test and McNemar test. Examiner reliability was determined by Cohen's kappa
score. Visual analogue scale (VAS) was used to assess the level of parental satisfaction.
RESULT All crowns but one were retained, and the majority (83 percent) had no facing fractures. Parental satisfaction was
high (9.4/10 on the VAS). Primary maxillary first molar crowns had more occlusal facing fractures than their
mandibular counterparts (P=.02). Primary mandibular second molar crowns showed more facing fractures than
their maxillary counterparts (P=.008). Both types showed no statistical difference in most categories, but Kinder
Krowns had more facing fractures (P<.02).
CONCLUSION Posterior preveneered crowns have predictable durability at 12 months while offering natural appearance to
restored teeth.
84. TITLE Assessment of oral hygiene and periodontal health around posterior primary molars after their
restoration with various crown types.
AUTHOR
LEVEL OF EVIDENCE
Beldüz Kara N1, Yilmaz Y
Int J Paediatr Dent. 2014 Jul;24(4):303-13. doi: 10.1111/ipd.12074. Epub 2013 Oct 28
IIc
AIM To compare the time-dependent changes in oral hygiene and periodontal health after restoring
primary posterior molars with a traditional stainless steel crown (SSC) or an aesthetic crown using
various measures of periodontal health and oral hygiene.
METHOD This investigation was a randomized, non-blinded prospective controlled clinical trial in which
264 crowns of different types were fitted onto the first and/or second primary molars of 76 children. The
oral hygiene and the gingival health of the restored teeth and the antagonistic teeth were evaluated
clinically and radiographically at 3- and 6-month intervals for 18 months after fitting the crowns.
RESULT The periodontal health of the control teeth was better than that of the remaining 215 restored teeth. The
oral hygiene, as measured by the simplified oral hygiene index, and gingival health, as measured by the
gingival index and the volume of gingival crevicular fluid, of the restored teeth, irrespective of crown type,
progressively increased during the 18-month study period.
CONCLUSION Oral hygiene and gingival health around a restored primary tooth deteriorate with time. Our results
suggest that SSC, an open-faced SSC, or a NuSmile(®) pediatric crown should be the
preferred crown type for restoring posterior primary teeth.
85. PRE-VENEERED STAINLESS STEEL CROWNS
These combine the durability of a stainless steel crown with the esthetics of a
resin facing.
The primary issues with these crowns are the need to reduce additional
coronal tooth structure, limitations in the ability to crimp the margins prior to
cementation, and loss of the esthetic acrylic facing, among others.
These crowns are available from various manufacturers: Cheng Crowns,
NuSmile, and Kinder Krowns.
86. Lopez-Loverich et al.(2015):- evaluated the retention of SSC vs. preveneered
crowns on primary anterior teeth & concluded that there was “good crown
retention rates for both crown types with no statistically significant difference
between them.”
O’Connell et al.(2014):- the clinical performance of two brands of stainless steel
veneered molar crowns after three years (NuSmile crowns and Kinder Krowns).
The study found that the primary problem with resin-veneered crowns used in
posterior primary molars was facing fracture.
In addition, when the adjacent tooth was missing, fracture was more likely to
occur, possibly due to the increased force of occlusion on the veneered crown.
87. TITLE SHEAR BOND STRENGTH OF PREVENEERED POSTERIOR SSC
AUTHORS
LEVEL OF EVIDENCE
Nihal BELDÜZ, 2006
AIM To evaluate the shear bond strength of veneer material of posterior preveneered
stainless steel crowns (SSCs).
METHOD 32 preveneered SSCs (lower first primary molar=8, upper first primary molar=8, lower
second primary molar=8 and upper second primary
molar=8) were used for this study. Specimens were kept in humid environment at 370C
for thirty days and exposed to thermocycling. Then, each veneered crown was cemented
on one of the cast dies. After twenty-four hours, force was applied on the occlusal
surfaces of the crowns according to primary molar occlusal relationship. The fractured
specimens were photographed under X10 magnification with a stereomicroscope.
Characterizations of the failure modes and fracture extents of the veneer material were
scored. Data were analyzed statistically.
88. RESULT For bond strength, there was a statistically difference between crown groups
(P<0.05). However, there were no significant differences between both failure
modes and fracture extents of the crown groups (P>0.05).
CONCLUSION Both lower and upper second molar crown groups showed higher shear bond strengths
than first primary molar crown groups. Veneer material was observed to fracture
commonly.
89. TITLE A clinical and radiographic evaluation of stainless steel crowns for primary molars
AUTHORS Aly A. Sharaf, Najat M. Farsi
Journal of Dentistry (2004), LEVEL OF EVIDENCE: 2b
AIM To evaluate clinically and radiographically the effect of stainless steel crowns placed on
primary molars on gingival and bone Structures
METHOD 254 crowns were evaluated in a sample of 177 children aged 3.5–12 years old with a mean
age of 7 years. The crown marginal extension, crown marginal adaptation, intact proximal
contact, gingival index and the duration of presence of the crowns, together with the oral
hygiene index of the child. Bitewing radiographs were used for evaluation.
RESULT Interproximal bone resorption was not significantly affected by either crown marginal
extension or adaptation, preserving tight proximal contact between molars, oral hygiene level
or duration of presence of the crown. On the other hand, there was significant bone
resorption when the crown was judged radiographically as non-satisfactory. While oral
hygiene level had a significant effect on the gingival index, presence or absence of proper
proximal contact did not have an effect on the gingival index.
CONCLUSION SSC are still a valuable procedure that has no harmful effect on the gingiva and bone
provided that good oral hygiene level was maintained.
90. AIM Multi-surface composite vs stainless steel crown restorations after mineral trioxide aggregate
pulpotomy: a randomized controlled trial.
AUTHORS
LEVEL OF EVIDENCE
Hutcheson C1, Seale NS, McWhorter A, Kerins C, Wright J.
Pediatr Dent. 2012 Nov-Dec;34(7):460-7.
1a
AIM Parents increasingly request esthetic restorations for their children's teeth. This split mouth,
randomized controlled trial compared primary molars treated with white MTA pulpotomies and restored
with either multi-surface composites (MSC) or stainless steel crowns (SSC).
METHOD Forty matched, contra-lateral pairs of molars received MTA pulpotomies and were randomly assigned
to MSC or SSC restorations and evaluated clinically and radiographically at 6 and 12 months. Two
calibrated, blinded examiners evaluated and scored radiographs.
RESULT Thirty-seven matched pairs were evaluated at 6 months, and 31 were available at 12 months. All teeth
in both groups were radiographically and clinically successful at 6 and 12 months. Dentin bridge
formation was noted in 20% of the primary molars by 12 months. Although not significant, the
composite group exhibited fewer intact clinical margins than the SSC group. The vast majority (94%) of
teeth restored with composite displayed gray discoloration at follow-up exams, which did not appear to
affect the quality of the restoration and is believed to be associated with the white MTA.
91. CONCLUSION The white MTA pulpotomies succeeded over 12 months regardless of the
restoration; however, the teeth restored with composite were not as durable
nor considered an esthetic alternative to the SSC.
92. TITLE The survival of resin modified glass ionomer and stainless steel crown restorations in
primary molars, placed in a specialist paediatric dental practice.
AUTHOR
LEVEL OF EVIDENCE
Roberts JF1, Attari N, Sherriff M.
Br Dent J. 2005 Apr 9;198(7):427-31.
IIb
AIM To prospectively report on the survival of resin-modified glass ionomer cement (RMGIC), photac-fil
and pre-formed stainless steel crown (SSC) restorations in primary molar teeth placed over a
seven-year period in a specialist paediatric dental practice under private contract of remuneration.
METHOD All primary molar restorations placed by a specialist paediatric dentist over a seven-year period
were reviewed and the outcome results recorded. Data were recorded at review visits until June 30,
2003. Data recorded included Class I restorations, Class II restorations and SSC. The Class II
cavities were either mesial or distal, with or without buccal/palatal extensions. If both proximal
surfaces were decayed or if after cavity preparation the resultant outline form was significantly larger
than the minimal classical form, RMGIC was not used; an SSC was placed instead. Stainless steel
crown preparation followed conventional guidelines. The crowns were cemented with reinforced zinc
oxide and eugenol (Kalzinol). The status was recorded as satisfactory restoration, tooth exfoliated,
tooth extracted for orthodontic reasons with the date of extraction, or needing replacement. If
replaced then the reason for replacement was also recorded.
93. RESULT
A total of 544 Class I RMGICs, 962 Class II RMGICs, and 1,010 SSCs were placed.
At the last review of each restoration, 98.3% of Class I, 97.3% of Class II RMGICs
and 97.0% of SSCs were either satisfactory or withdrawn intact.
CONCLUSION Under the conditions of private specialist practice-based study SSCs continued to prove
very successful for the restoration of larger cavities and for pulp-treated primary molar
teeth. For the smaller cavities RMGIC were also very successful.
94. REFERENCES
Duggal M.S., Curzon M.E., Fayle S.A., Polar M.A., and Robertson A.J.: Restorative techniques in pediatric
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Finn S.B.: Clinical pedodontics. 3rd Ed, Philadelphia, W.B. Saunders, 184-186, 1967.
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Rapp R.: A simplified, yet precise technique for the placement of stainless steel crowns on primary teeth. J.
Dent. Child. 33: 101-112, 1966
Mink J.R and Bennett I.C.: The stainless steel crown. J. Dent. Child, 35: 186-196, 1968.
Kennedy D.B.: The stainless steel crown. Pediatr. Oper. Dent. Bristol 1976, J. Wright and Sons Ltd
Hartman C.R.: The open face stainless steel crown: An esthetic technique. J. Dent. Child, 31-33, Jan-Feb,
1983.
Lee JK. Restoration of primary anterior teeth: review of the literature. Pediatr Dent 2002;24:506-10
Guelmann M, Gehring DF, Turner C. Retention of veneered stainless steel crowns on replicated typodont
primary incisors: an in vitro study. Pediatr Dent 2003;25:275-8
Unitek-california, , 3M-minneapolis, rocky mountain-denver//NICKEL BASE –already work hardened while AUSTENTIC soft and malleable & harden when adapted with pliers… Ni base fit easily& require least adjustment(stephen wei)
Untrimmed -THESE ARE CROWNS WITH STRAIGHT SIDES & MARGINS THAT FOLLOW THE GINGIVAL CONTOUR. THE GINGIVAL MARGINS CAN BE TRIMMED WHERE NECESSARY & ALSO NEED CONTOURING & CRIMPING TO ENSURE GINGIVAL ADAPTATION TO THE PREPARED TOOTH. Pre trimmed -Parallel crown walls saves chair time, minimizing the need for buccal, lingual, and mesial tooth reduction.
Consistent wall thickness helps prevent bite through and minimizes trial fitting distortion.
The Molar Crowns have shallow occlusal anatomy which reduces rocking during mastication, with minimal occlusal interference.
Pre contoured –more rounded..POSSESSS MORE DIFFICULTY IN ADAPTATION SINCE TRIMMING WILL RESULT IN REMOVAL OF MANUFACTURERS GINGIVAL CRIMP & inc dimensiond os cervical margin
Chromium oxidizes and forms a thin surface film of chromium oxide (Cr2O3), known as “passivating film” which protects against corrosion.
Austenitic stainless steel is used extensively for the fabrication of dental appliances and is composed of chromium (11.5-27%), nickel (72.2%.),and carbon (0.25%). Nickel-Base Crowns Inconel 600 alloy 72% nickel 14% chromium 6-10% Fe 0.04% carbon 0.35% manganese 0.2% silicon
