Comparison of the new matrix system with traditional fixed prosthodontic impression procedures.

This article compares the methods and effectiveness of traditional fixed partial denture impression systems, which includes the matrix impression system, in relation to the registration of the finish lines and sulci of tooth preparations in the formation of a full arch impression. Concepts relating to custom trays, retraction, homeostasis, sulcular cleansing, sulcular flange registration, configuration and strength, viscosity of elastomeric impression materials, and delivering the impression material into the sulcus are reviewed. Several concepts are questioned and alternative procedures are proposed. Forces that impact the gingival tissues and determine the success of the impression are briefly described.