Stainless Steel Crowns/Open Faced Stainless Steel Crowns

Stainless steel crowns were introduced to pediatric dentistry by the Rocky Mountain Company in 1947 and made popular by W. P. Humphrey in 1950. Until then the treatment for grossly decayed primary teeth was extractions. Stainless steel is composed of iron, carbon, chromium, nickel, manganese and other metals. The term stainless steel is used when the chromium contents exceeds 11% (usually a range of 12 to 30%. The chromium oxidizes and forms a protective film of chromium oxide which protects against corrosion. While originally intended for the restoration of posterior primary and young permanent teeth, its use was expanded to badly decayed anterior teeth. Although, more durable and retentive than amalgam or composite they are unaesthetic, especially on the anterior teeth. With aesthetics of their child’s smile of extreme importance to parents, many opted for extraction and prosthetic replacement of severely decayed teeth rather than placement of stainless steel crowns. The advent of composite bonding, allowed for a composite facing to be placed on the facial surface of the tooth, thus improving aesthetics. Open faced stainless steel crowns combine strength, durability and improved aesthetics, however they are time consuming to place as the composite facing cannot be placed until the stainless steel crown cement sets. Bleeding of the color of the metal margins surrounding the composite adds a grayish tinge to the tooth that is accentuated next to the white enamel of an adjoining or opposing primary tooth.

Manufacturers of anterior stainless steel crowns are: 3M Espe-Unitek Crowns, St. Paul, MN; Cheng Crowns, Exton, PA; Hufriedy Manufacturing Inc, Chicago, IL and Acero Crowns, Seattle, WA.

The advantages and disadvantages of stainless steel crowns and open faced stainless steel crowns are summarized as follows:

Stainless Steel Crowns


  • They are very durable, wear well and are retentive.
  • The time for placement is fast compared to other techniques.
  • They may be used when gingival hemorrhage or moisture is present or when the patient exhibits less than ideal cooperation.
  • They are fairly inexpensive (approximately $6/crown).


  • Aesthetics are extremely poor. Some parents may opt for extractions in lieu of restoration of the teeth.
Open Faced Crowns


  • The aesthetics are fair. (The metal shows through the composite facing.)
  • They are very durable, wear well and retentive.
  • The materials are fairly inexpensive.


  • The time for placement is long as it involves a two-step process (crown cementation/composite facing placement.
  • Placement of the composite facing may be compromised when gingival hemorrhage or moisture is present or when the patient exhibits less than ideal cooperation.


Although stainless steel crowns, as a standalone technique for anterior restorations, are rarely used, mastering the technique is necessary for fabrication of the more aesthetic open faced stainless steel crown.

Stainless Steel Crown Technique

  • Anesthetize the teeth to be restored and place the rubber dam.

  • Select a primary stainless steel crown with a mesio-distal incisal width equal to the tooth to be restored by placing the incisal edge of a stainless steel crown against the unprepared tooth.
  • Remove decay with a medium to large round bur in a slow speed handpiece. If pulp therapy is required, do it at this time.
  • Using a 169L bur or a fine tapered diamond, reduce the incisal edge by 1.5mm.
  • Reduce the facial surface by 1mm and the lingual surface by 0.5mm. Create a feather-edge gingival margin. Round all line angles.
  • Try the pre-selected crown on the tooth.

Anterior crowns are manufactured with an ovoid shape with a small facio-lingual dimension. Change the shape to allow the crown to passively slip on the tooth. Squeeze the crown slightly mesio-distally with a pair of Howe no. 110 pliers to increase the facio-lingual dimension.

  • Reseat the crown.  The crown should extend 1mm under the gingival margin.  The fit of the crown should be snug without rocking.

  • Trimming, if necessary, is best done with a heatless stone on a straight slow speed handpiece followed by polishing with a rubber point.
  • Contouring and crimping are necessary to insure a good marginal fit.  Use a no. 137 Gordon plier to adapt the margin.  Check the marginal fit with an explorer.

  • Seat and cement the crown. Remove excess cement from the crown with a wet gauze. The cement must be completely set before preparation and placement of the open faced veneer.
Open Faced Stainless Steel Crown Technique
  • Once the cement is set, cut a labial window in the cemented crown using a no. 330 or no. 35 bur.
  • Extend the window:
    • Just short of the incisal edge.
    • Gingivally to the height of the gingival crest.
    • Mesio-distally to the line angles.
  • Using a no. 35 bur remove the cement to a depth of 1mm.

  • Place undercuts at each margin with a no. 35 bur or with a no. ½ round bur.

  • Smooth the cut margins of the crown with a fine
    green stone or white finishing stone.
  • After using a glass ionomer liner to mask differences
    in color between remaining tooth structure and
    cement place a layer of bonding agent.
  • Place resin based composite into the cut window
    forcing the material into the undercuts and polymerize.
  • Add additional material in 1mm increments and polymerize.

  • Finish the restoration with abrasive disks.

  • Run the disks from the resin to the metal at the margins so as not to discolor the resin with metal particles.

  • Repeat the procedure for the remaining teeth.

  • While more aesthetic than a conventional stainless steel crown, a shortcoming of an open faced stainless steel crown is the bleeding of the metal color from the lingual and interproximal surfaces through the composite resulting in a grayish tinge to the facing.