Dental Problems

What is the Procedure for Stainless Steel Crown Preparation?

ToothStainless steel crown is semipermanent restoration. These are one among the moderately recent advances. These stainless steel crowns are recommended for the lost tooth structure restoration and to stabilize the lost tooth with the prefrabricated crowns. In this article, there is a brief discussion on the procedure for stainless steel crown preparation. Let us examine them.

procedure for the stainless steel crown preparation:

  • Initial Adaption of Crown:

    Two principles related to stainless steel crown length and crown margin shapes that are based on an understanding of the tooth morphology and gingival tissue contours were presented by Spedding (1984).

    • The crown should be of a correct length and its margins can be adapted closely to the tooth. This can be achieved when the finished crown is correctly seated on the prepared tooth with its occlusal surface in the occlusal plane and its margins placed just apical to the marginal gingival crests. After the correct size crown is placed on the prepared tooth, the crown height can be reduced by removing about 1mm of the crown initially with a crown and bridge scissors or with a corborundum wheel on a slow speed straight handpiece, which shapes the margins simultaneously.
    • For shaping the crown margins, mark 3 light points on the metal at the mesiobuccal, buccal and distobuccal and at the mesiolingual, lingual and distolingual surfaces at the crest of respective marginal gingival without compressing the marginal gingival. These marks on the metal corresponds to the greater diameter of the tooth. Final finished margins are placed approximately 1mm below these marks. The correctly shaped finished crown margins are parallel to the contours of the marginal gingival of the tooth, about 1.0mm into the gingival cervice.
  • Seating the crown:

    • Now the crown is tried on the preparation by seating the lingual first and applying pressure in a buccal direction so that the crown slides over the buccal surface into the gingival sulcus.
    • Resistance should be felt as the crown slip over the buccal bulge.
    • Each time the crown is placed on the tooth, gingival tissue should be carefully examined so that the margins are in the gingival sulcus.
    • They should not compress and produce blanching of the marginal gingival tissue.
  • Crown contouring:

    • Initial crown contouring is performed with a 114 plier (ball and socket pliers) in the middle 1/3rd of the corwn to produce a belling effect.
    • This will give the crown a more even curvature.
    • Contouring of proximal metal surface is not done with these pliers as they are ready in contact with the adjacent teeth.
    • Though occasionally the #112 (Abell) pliers are used to contour a proximal surface to establish correct contact.
    • Adaptation of the gingival 1/3rd of the crown is done with the 137 Gordan pliers.
  • Crown Crimping:

    Any marked gingival crimping of the crown can also be done with Unitek 800-412 pliers. The tight marginal fit aids in the following:

    • Mechanical reduction of the crown.
    • Protection of the cement from exposure to oral fluids.
    • Maintainance of gingival health.

    During the trail fitting and cementation, the crown should be placed from lingual and rolled towards buccal surface. In this way, maximum undercut on the buccal surface is more easily covered.

  • Checking the final adaptation of the crown:

    • The crown must snap into place. It should not be able to be removed with finger pressure.
    • 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.
    • The properly seated crown will correspond to the marginal ridge height of the adjacent tooth and is not rotated on the tooth.
    • Crown is in proper occlusion and should not interfere with the eruption of the teeth.
    • There should not be any high points when checked with an articulating paper.
    • The crown margin extends about 1mm gingival to gingival crest.
    • No opening exists between the crown and the tooth at the cervical margins. Crown margins closely adapted to the tooth and should not cause gingival irritation.
    • Restoration enables the patient to maintain oral hygiene.
  • Finishing and polishing:

    • Accumulation of the plaque and inflammation of gingival is commonly seen in practice of restorative dentistry due to rough and unpolished restoration.
    • To avoid these complaints, the crown should be polished prior to cementation with a rubber when to remove all scratches.
  • Procedure of polishing:

    • While polishing the crown, margin should be blunt since knife edge finish produces sharp ends which act as areas of plaque retention.
    • A broad stone wheel should run slowly, in light brushing strokes, across the margins towards the center of the crown.
    • This will draw the metal closer to the tooth without reducing the crown height and thus improves the adaptation of crown.
    • A wire brush can be used to polish the margins to a high shine.
    • To give a fine luster to crown, Rouge, whitting or a fine polishing material can be used.
  • Radiographic confirmation of the gingival fit:

    • Before cementation, a bite wing is taken to verify proximal integrity. If the crown is too long, there is still an opportunity to reduce the length.
    • If it is too short, then add an orthodontic band or adaptation of another crown is indicated.

The above articles discusses briefly about the

procedure for stainless steel crown preparation

. Later this procedure, cementation is done on a clean dry tooth. There are also some special considerations for stainless steel crowns. These later procedure is discussed in other articles. Stainless steel crown is a semi-permanent restoration for restoring the lost tooth and for stabilizing it.

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