Notes

Outline

Composite Crowns Anne S. Aiello, D.M.D.

Objectives To describe the indications for a composite crown on a primary incisor. To properly prepare a dentoform tooth for a composite crown. To properly adapt a crown form and to restore a dentoform tooth.

Restoration of Class IV Caries in Primary Anterior Teeth Esthetic Resin Restoration Stainless Steel Crown Open-Face Steel Crowns Composite Crowns

Anterior Stainless Steel Crowns Esthetics - poor Durability - very good Time for placement - fastest Selection criteria - severely decayed, esthetics of minimal importance, gingival hemorrhage not controlled, inadequate patient cooperation

Open Faced Stainless Steel Crown Esthetics - okay Durability - good, although facing may be dislodged Time for placement - takes longest to place due to two-step procedure Selection criteria - severely decayed teeth, durabilty needed, esthetics are a concern

Crown Form Selection Select the appropriate crown form size from the mesio-distal measurement (mm)  of the tooth’s incisal edge, or by direct comparison

Tooth Preparation Incisal reduction 1-1.25 mm Proximal reduction - parallel mesial and distal slices to break contact with the adjacent tooth and to allow enough bulk to give strength to the final restoration .5-1 mm

Utilize a fine diamond or a 699

Tooth Preparation Buccal reduction - to allow the placement of the restoration within the normal buccal lingual width of the tooth restored .5-1 mm Lingual reduction - to allow for the necessary bulk for the strength of the crown and to prevent for any occlusal interferences

Buccal Reduction

Lingual Reduction

Circumfrential Undercut Shoulder Terminates at the crest of the gingiva Shoulder depth should be .75-1 mm Use inverted cone

Variation

Crown Adaptation Carefully trim off the cervical collar with curved festooning scissors Trim crown form so that when seated, it covers the shoulder but extends no more than 1 mm past tge shoulder

Trial Fitting of Crown Form Try on trimmed crown form Incisal edges should line up Place hole in incisal edge of crown with an explorer to allow vent for composite to flow through during crown placement

Crown Placement Etch tooth with phosphoric acid for 30 seconds Thoroughly wash and dry etched surface Apply bonding agent according to specifications

Crown Placement Carefully pack the crown form resin to avoid entrapment of air bubbles

OOH, AAH. . . Position the filled crown form over the prepared tooth so it extends 1mm over the gingival margin Remove excess resin from margins with an explorer before polymerizing Slice crown form

Minimal Finishing and Polishing Peel it away from composite crown Finish margins Adjust occlusion DO NOT FINISH the labial surface polymerization of the resin against the plastic provides the smoothest and most stain resistant surface

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