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Stainless steel crowns

Types of stainless steel crowns
Stainless steel crowns are available in six sizes for both primary molars and
permanent first molars. Sizes 4 and 5 are the most often used. A size 7 is available for
extra -large teeth. These sizes are supplied in kit form, with the user needing to rec ord
only those sizes frequently used.

1. Untrimmed crowns: These crowns are neither trimmed nor contoured, require lot of

adaptation, thus are time consuming.
2. Pre -trimmed crowns: These crowns have straight, non -contoured side but are
festooned to follow a line parallel to the gingival crest. They still require contouring
and trimming .
3. Pre -contoured crowns : These crowns are festooned and are also precontoured
although a minimal amount of festooning and trimming may be necessary

Advantages

SSCs offer the following advantages:
1. excellent durability
2. the least frequently replaced restoration
3. full coverage assists in controlling caries progression
4. can be done quickly assuming good patient behavior and operator skill.

Disadvantages

SSCs pose the following disadvantages:
1. parents may object to appearance
2. preformed crowns may be challenging to adapt to tooth
3. transient damage to periodontium
4. may contribute to ectopic eruption of first permanent molars

Indications

1. Extensive Caries
2. Developmental Enamel Defects
3. Following Pulp Therapy
4. For Temporary Restoration of a Fractured Tooth
5. As an Abutment for Space Maintainer

Contraindications

1. Primary posterior teeth in which conservative amalgam restorations can be
placed. Quality of amalgam restorations continues to be the preferred
restoration in many primary molars.
2. Exfoliation: Teeth expected to exfoliate withi n a brief period (6 to 12 months)
and radiograph shows over half the primary root resorbed.
3. Poor esthetics in the anterior teeth
4. Cost: The cost -effectiveness of any restoration should be co nsidered in
treatment planning;
5. Periodontal problems:
6. Patients w ith nickel allergies .

Steps in Stainless Steel Crown Procedure

• Occlusal reduction

• Proximal reduction

• Buccal and lingual reduction
• Selection of crown
• Initial adaptation and retention
• Crown contouring
• Crown finishing
• Final adaptation
• Radio graphic confirmation of the gingival fit
• Cementation
• Postoperative instructions.

Evaluation Criteria for Tooth Preparation

• The occlusal clearance is 1.5 to 2 mm. (A sheet of wax may be used to indicate area,
of insufficient reduction).
• The proximal slices converge toward the occlusal and lingual, following the normal
proximal contour.
• An explorer can be passed between the prepared tooth and the proximal tooth at the
gingival margin of the preparation.
• The buccal and lingual are red uced at least 0.5 mm with the reduction ending in a
featheredge 0.5 to 1 mm in to the gingival sulcus.
• The buccal and lingual surfaces converge slightly toward the occlusal.
• The occlusal third of the buccal and lingual surfaces is gently rounded.
• All point and line angles in the preparation are rounded and smoothed.

Checking the Final Adaptation of the Crown

1. The crown must snap into place.
2. It should not be able to be removed with finger pressure.
3. The crown should fit so tightly that there is no rocking on the tooth. Moderate
occlusal displacement forces at the margin do not displace the crown.
4. The properly seated crown will correspond to the marginal ridge height of the
adjacent tooth and is not rotated on the tooth.
5. Crown is in proper occlusion and should not interfere with the eruption of the teeth.
6. There should not be any high points when checked with articulating paper.
7. The crown margin extends about 1 mm gingival to gingival crest.
8. No opening exists between the crown and th e tooth at the cervical margins. Crown
margins closely adapted to the tooth and should not cause gingival irritation.
9. Restoration enables the patient to maintain oral hygiene


رفعت المحاضرة من قبل: Sultan Alsaffar
المشاهدات: لقد قام 12 عضواً و 34 زائراً بقراءة هذه المحاضرة






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