Figure 1. SEM micrographs of replicas of post spaces in endodontically treated teeth. (A) An unbonded post space with smear layer intact, showing the transudation of water droplets through the smear layer (open arrowheads). (B) An unbonded post space after acid-etching, showing the presence of water droplets over the tubular orifices (arrows). (C,D) Post spaces bonded with All-Bond 2, a three-step total-etch adhesive, in preparation for cementation of fiber posts. (C) A representative example of the bonded root dentin that was completely devoid of fluid movement through the adhesive. (D) A representative example of the root dentin in which there was minimal fluid movement through the adhesive, resulting in the presence of discrete fluid droplets (pointers) along the adhesive surface. These water droplets were trapped during the setting of the polyvinyl siloxane impression material.