Final impressions: a review of material properties and description of a current technique.

Esthetic rehabilitations are characterized by a sequence of well-structured clinical and laboratory steps, during which different kinds of impressions are required. This review presents a survey of the most clinically relevant physical properties that characterize final impression materials and their interactions with the products they are commonly in contact with. The principal steps of an esthetic rehabilitation involving a diagnostic phase, together with a rational step-by-step approach to final impressions, are described. The one-step/double-mix impression using polyvinyl siloxane materials associated with a "double cord" gingival displacement is explained.