Audio Tutorial - Intermediate

1. STAINLESS STEEL CROWNS IN PEDIATRIC
DENTISTRY

2. CONTENT
 INTRODUCTION
 STAINLESS STEEL CROWN
 HISTORY
 CLASSIFICATION
 COMPOSITION
 INDICATIONS
 CONTRAINDICATIONS

3.  ADVANTAGES
 DISADVANTAGES
 SIZE FOR SSC
 ARMAMENTARIUM
 TECHNIQUE
 MODIFICATIONS
 REFERENCES

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.

30. DISADVANTAGES
1. Unsightly metallic appearance
2. Cannot be used when the tooth is only partially erupted.
3. Gingival hyperplasia

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.

32. PRIMARY ANTERIOR TEETH (KIDZ CROWN)

33. PERMANENT MOLAR (3M)

34. ARMAMENTARIUM
Burs and stones:
 No. 169L or No. 69L F.G.
 No. 6 or No. 8 R.A.
 No. 330 F.G.
 Tapered diamond F.G.
 Round bur
 Flame shaped diamond bur
 Long thin tapered
 Green stone or heatless stone/rubber wheel
 Rough polishing wheel
 Wire wheel-for finishing crown

35. CONTOURING PLIERS

36. PROXIMAL CONTOURING

37. CRIMPING PLIERS

38. CURVED SCISSOR/ CROWN
CUTTING SCISSOR

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. STEPS
 Pre-operative occlusion
 Local anesthesia
 Caries removal
 Occlusal reduction -1.5 -2mm (Keneddy)

43. FOR 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.
 Mesial and distal clearance and a smooth taper obtained free of ledges and
shoulders.
 Line angles rounded

44.  The gingival finishing line should be a feather edge.
 A taper mesially and distally will help to achieve this.
 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

45. 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.

46. 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.

47. 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

48.  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

49. 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.

50.  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

51. 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.

52.  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.

53.  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.

54. 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.

55. Radiographic Confirmation of Gingival Fit
 Crown too long-reduce the length.
 Crown short- orthodontic band or adaptation of another crown.

56. CEMENTATION
 Rinse and dry the crown.
 GIC, ZnPO4, polycarboxylate or self
curing resin-RMGI preferable
 Excess cement should be removed
using explorer tip, dental floss.

57. MODIFICATIONS OF STAINLESS STEEL CROWNS
 In 1971 Mink and Hill reported several ways of modification of stainless steel
crown when the crowns are either too large or too short.

58. OVERSIZED
CROWN

59. UNDERSIZED
CROWN

60. DEEP PROXIMAL LESIONS
 Dental caries that extend
beyond the crown.
 Application of fluoride varnish on
tooth structure before placement of
SSC.

61. 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.

62. REFERENCES
 Duggal M.S., Curzon M.E., Fayle S.A., Polar M.A., and Robertson A.J.: Restorative techniques in pediatric
dentistry: An illustrated guide to the restoration of extensively carious primary teeth, London, Martin Dunitz; 8,
72, 1995.
 Finn S.B.: Clinical pedodontics. 3rd Ed, Philadelphia, W.B. Saunders, 184-186, 1967.
 Mathewson.: Fundamental of pediatric dentistry. 3rd ED. Quintessence Publishing Co. Shicago, 1995
 Mc Donald.: Dentistry for child and adolescent, 5th ED,1996; The C.V. Mosby Co
 Pinkam: Pediatric Dentistry, Infancy Through Adolescence. 3rd ED (1999) W.B. Saunders Company.
 Shobha Tandon: Text Book of Pedodontics. Ist ED, 2001, Paras Publishing Co
 Stewart: Scientific foundations and clinical practice in pediatric dentistry. C.V. Mosby Co., 1982
 Waggoner W.F. and Cohen H.: Failure strength of four veneered primary stainless steel crown. Pediatric.
Dent. 17(1): 36-40, 1995
 Croll T.P and Helpin M.L.: Preformed resin-veneered stainless steel crown for restoration of primary incisors.
Quintessence Int. 27(5): 309-313, 1996

63.  Einwag J. and Dunninger: Stainless and crown versus multispace amalgam restorations, an 8 year
longitudinal clinical study. Quint. Int. 27(5): 321-328, 1966.
 Humphrey W.P.: Use of chrome steel in children’s dentistry. Dent. Surv. 26: 945-953, July 1950.
 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

64. Thank You