In the described technique, a vinyl polysiloxane material is used as a matrix for the indirect fabrication of multiple custom-cast posts and cores. The matrix technique enables the clinician to fabricate multiple posts and cores in a short period of time. The form, harmony, and common axis of preparation for all cores are well controlled before the definitive crown/fixed partial denture restorations are fabricated. Oral tissues are not exposed to the heat of polymerization or the excess monomer of the resin material when this technique is used.

This article describes a simple procedure of recording contours of an existing cast post and core that needs to be reconstructed, using a polyvinyl siloxane material as a matrix for fabrication of a new cast post and core in a relatively short time with reduced cost. The procedure involves the use of an acrylic resin material under pressure, which minimizes void formation in the post-and-core pattern.

Statement of problem. Exposing the tooth structure to chemicals used in displacing the gingival tissue is inevitable. Purpose. This study was undertaken to microscopically examine the effect of tannic acid on the prepared dentin surface. Material and methods. Forty recently extracted intact human teeth were mounted for buccal surface preparation. Teeth were equally divided into 10 groups.