Stainless steel crowns- TP Croll contributions

Crossbite correction with reverse stainless steel crowns

• Cementation of the crown with its lingual metallic surface facing labially creates an elongated inclined plane which, when struck by the incisal edge of the mandibular incisor deflects the maxillary tooth facialy and the opposing tooth lingually.

• Reversed stainless steel crown crossbite correction can also be used successfully in the primary dentition

• The chief disadvantage of using a steel crown form for correction of crossbite is that the prefabricated crowns are sometimes difficult to adapt in such a way that the desired mechanical advantage for appropriate tooth movement can be obtained.

• Other disadvantages are the metallic appearance of the cemented crown form and the possibihty that the cement bond will fail, resulting in loss of the crown form.

Increasing Occlusal Surface Thickness of Stainless Steel Crowns: A Clinical Technique• Patients with tooth grinding habits may tend to wear through

the occlusal surfaces of stainless steel crowns.• A technique is described which prevents this problem by

increasing metal occlusal surface thickness of the crown

• Perform the recommended procedures for stainless steel crown preparation

• Prior to crown adaptation select a Unitek brand crown of the next smallest size

• Using a high speed carbide bur, cut the occlusal table from the smaller crown

• Roughening the inside of the larger crown and the occlusal surface of the smaller crown segment with a diamond stone

• Place pieces of silver solder inside the larger crown and soldering flux on the smaller segment

• Place the cut occlusal segment over the solder within the crown.

• A high heat, fine-flame torch is then used to melt the solder, attaching the two stainless steel surfaces.

• Excess solder expressed around the internal margins suggests even solder flow.

• A metal instrument or graphite pencil point may be used to gently push the stainless steel surfaces together while the solder is flowing to eliminate void spaces.

Stainless steel crown, welded sheath, and wire loop for posterior space maintenance• Indications

– Premature loss of a primary first molar with caries affecting the primary second molar in the same quadrant.

– Premature loss of a primary second molar with insufficient eruption of the permanent first molar to facilitate banding for a holding arch, or band and loop space maintainer

Technique

• A full arch impression is taken initially, and a model is poured in fast-set plaster or stone.

• Usual procedure for fabricating a preformed stainless steel crown is performed in the mouth

• Orthodontic sheath designed to fit the double bend of an .036 stainless steel wire is welded to the buccal aspect of the crown.

• Wire fabrication• Wire is tied into the sheath securely

with .010 ligature wire

Marginal Adaptation of Stainless Steel Crowns

Step 1

• After the proper size crown form has been selected, marginal adaptation can be accomplished as follows:– With a large abrasive wheel (“heatless stone”) or diamond wheel on a

straight slow speed angle, crown length is custom cut

Step 2

• With crimping pliers, the edge of the crown form (0.5- 1 mm) is bent slightly inward around the crown periphery

Step 3

• The abrasive wheel is then applied to the edges, rotating toward the margins from the occlusal direction.

• Such action thins the marginal stainless steel material and curves it slightly more toward the axial walls of the tooth

Step 4

• The crown surfaces are then smoothed and polished with a rubber wheel, applied in the same direction

Step 5

• For final finishing, the crown form can be smoothed and polished with a cloth or chamois wheel on the dental lathe, using Tripoli polishing agent and jeweler’s rouge (iron oxide)

Preformed resin-veneered stainless steel crowns for restoration of primary incisors

ZnOE pulpotomy and Stainless steel crown for primary posterior teeth, 1992