Stainless Steel Crowns Flashcards
What are stainless steel crowns composed of?
Iron, carbon, chromium (18%), nickel (8%), manganese, and other metals
Stainless steel is the term used for chromium content above 11%
What are SSCs?
Prefabricated crown forms which can be adapted to an individual tooth and cemented in place to provide a definitive restoration
What are the indications for placement of SSCs?
Caries involving 3 or more surfaces
Developmental enamel defects
Fractures
Rampant caries
Recurrent caries
Severe bruxism
Following pulp treatment
Orthodontic or prosthetic appliance retention
Hypoplastic enamel
For children unlikely to attend regular recall appointments
For correcting anterior cross-bite in the primary dentition
In patients undergoing restorative care under GA if 2 or more surfaces are involved
What are the contraindications for SSCs?
Primary teeth close to their exfoliation
Patients with known nickel allergy or sensitivity
What are the advantages of SSCs?
Low cost
Less chair time
Protection of the tooth from further decay
Availability of several sizes
Durability
Resistance to tarnish
Absence of mercury
Ability to regain vertical dimension and retain occlusion
Maintenance of morphological form to preserve the health of gingival tissues
Preserves arch length
What are the steps to placement of a SSC?
Administer LA
Isolation
Tooth preparation
SSC selection
SSc Contouring and trial fit
Cementation
How is the tooth made ready for SSC?
Check the size
Place wedges to separate neighbouring teeth and reduce risk of iatrogenic damage.
Depress gingival tissues and rubber dam
Occlusal reduction of 1.5mm
Interproximal reduction
How is the occlusal reduction of the SSC done?
Occlusal reduction is approximately 1.5mm to provide clearence for the crown and must follow occlusal contours to ensure maximum resistance to displacement.
How is proximal reduction done?
Nearly vertical slices to contact areas and to create space for the crown
Enough clearance is confirmed by passing an explorer through the space.
Avoid excessively tapered preparation and cutting a shoulder at the gingival margin
Should buccal and lingual surface be reduced?
NO, only time there is an exception is mandibular molar when the mesiobuccal bulge is too much.
How is a SSC prep finished?
All the sharp line angles and corners should be rounded off
What should we look for during trial fitting?
Curvature of the gingiva in the cervical region of the primary molars is important. It must be reproduced in the crown for it to fit in the gingival crevice without causing damage to soft tissue.
Cervical margin of a SSC should be no more than 1mm below and parallel to the gingival margin
How do SSCs get retention?
Snap fit achieved by the margin of the crown engaging under cuts in the crevice region
How can the SSC be contoured? What are the instruments used?
Using contouring pliers.
Gorgon: General contouring and shaping can be done by holding the pliers still and moving the crown and closing the jaws.
Johnson: General contouring by closing the jaws of the pliers and smoothing wringles by drawing the jaws around the margin of the crown.
Crimpling pliers: Crimpling of the margin by closing the jaws and holding the crown still whilst moving the pliers inwards.
Abell ball and socket help produce contact point by closing the jaws.
What part of the crown should be crimpled?
Last 1 to 2mm of the gingival margin of the crown.
