Indirectly formed matrix for multiple composite core restorations: two clinical treatments illustrating an expanded technique

The technique described in this report is an expansion of a previously reported intraoral procedure for directly developing a matrix for the fabrication of composite cores. The expanded method allows a matrix to be created indirectly after the involved teeth are trimmed or restored on a cast into slightly oversized crown preparations before the treatment visit. The cast may serve for both the matrix and the interim fixed restoration, enabling fabrication by the dental laboratory. A semirigid (occlusal registration) elastomeric material is used to form the matrix. The matrix is used to apply the composite and shape the cores after the abutment teeth have been prepared, pins or posts have been placed, and adhesive procedures have been implemented. The elastomeric matrix can be modified for use as the impression matrix. The described technique allows the simultaneous formation of multiple composite cores. An alternative method in which light-polymerized core composite is used with a vacuum-formed, dual-laminate transparent matrix is described and compared with the semirigid elastomeric matrix.