Composite matrix for large, non-wedgeable Class III or Class IV preparations with gingival or subgingival margins

Dentists sometimes are required to place a matrix to restore large Class III or Class IV preparations that have gingival or subgingival margins or are prepared in rotated or malposed teeth. In these situations, dentists sometimes cannot place a wedge between the prepared tooth and a neighboring tooth because the wedge cannot engage enough interproximal tooth structure to firmly anchor both itself and a matrix strip. This article presents a technique for placing a matrix around such large, non-wedgeable Class III or Class IV preparations.