Dental Problems

Stainless Steel Crown -Types and Modification

Types of Dental ElevatorsIn the young permanent and primary teeth, a semi-permanent restoration is used which is termed as stainless steel crown. Humphrey in 1950 introduced it as a chrome-steel crown which is known as stainless steel crown. It has been proven to have a favor in the pediatric dental and clinical practice. In this article, there is a brief discussion on the stainless steel crown -types and medication. Let is examine them.

Different types of stainless steel crowns

The following are the different types of stainless steel crowns:

  • Untrimmed crowns:

    • The untrimmed crowns are neither trimmed nor contoured.
    • They require lot of adaptation and this are time consuming.
    • Example of untrimmed crowns is Rocky mountain.
  • Pretrimmed crowns:

    • The pretrimmed crowns have straight, non-contoured sides but are festooned to follow a line parallel to the gingival crest.
    • They still require contouring and some trimming.
    • Examples of pretrimmed crowns are Unitek stainless steel crowns, 3M Co., st. paul, MN: and Denvo crowns, Denvo Co. Arcadia, CA.
  • Precontoured crowns:

    • The precontoured crowns are festooned and are also precontoured though a minimal amount of festooning and trimming may be necessary.
    • Examples of precontoured crowns include Ni-Chro Ion crowns and Unitek stainless steel crowns, 3M Co., st.paul,Mn.

Stainless steel crown modification

In 1971, Mink and Hill reported several ways of modifying the stainless steel crown when the crowns are either too large or too short.

  • Undersized tooth or the oversized crown:

    • This commonly occurs due to a long standing interproximal caries, space loss has occurred. To reduce the crown circumference, a cut is made up of the buccal surface to the occlusal surface.
    • The cut edges are re-approximated to overlap one another making circumference smaller.
    • The crown is tried on the tooth and amount of overlapping necessary is marked on the crown.
    • The overlapped edges are then spot welded.
    • The crown is polished with a rubber wheel and fine abrasives.
  • The oversized tooth or the undersized crown:

    • Separate the edges as needed and weld a piece of 0.004 inch orthodontic band material across the cut surface.
    • After contouring, apply the solder to fill any microscopic deficiency in seal. Polish the soldered crown.
  • Deep subgingival caries:

    • One approach is to complete the indicated pulp treatment and then restore the cavity preparation with silver amalgam.
    • Now the silver amalgam is considered substitute for the tooth structure.
    • The proximal areas are sliced as in a routine crown preparation.
    • Stainless steel crown is adapted with amalgam substitutes for tooth structure at the interproximal finish line.
    • If the subgingival caries occurs interproximally, the undestooned Rocky mountain crown will be deep enough to cover the preparation.
    • Another method is to solder an extension on interproximal areas of the crown.
  • The open contact:

    • If the closed contact are (except for the primate space) is not established, it will result in food packing, increased plaque retention and subsequently gingivitis.
    • This problem can be solved by selection of a larger crown or exaggerated interproximal contour can be obtained with a 112 (ball and socket) plier to establish a close contact. Interproximal contour can also be build by addition of a solder.
  • Open faced stainless steel crowns:

    • The stainless steel crown can be modifies in anterior teeth by a open faced stainless steel crown, which is simply a stainless steel crown with the labial surface trimmed away to leave a crown perimeter which is then restored with a resin veneering.
    • This has two advantages which are mentioned below:
      • Esthetic are often improved
      • The tooth structure is accessible for pulp testing.

The above article discusses briefly about the different types of stainless steel crown and the modification of stainless steel crown.

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