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 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).
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|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
Open Faced Stainless Steel Crown Technique