ABSTRACT
Aim:Surface detail reproduction and dimensional stability of Poly vinyl siloxane impression material is most important property for final success of fixed partial denture. Purpose: This study was carried out to determine the effect of retraction cord medicaments (epinephrine, aluminum chloride and ferric sulfate) on the dimensional accuracy and surface detail reproduction of polyvinyl siloxane impressions. Method and materials: Polyvinyl siloxane impressions were made of standardized metal dies (American Dental Association [ADA] specification No. 19) and was treated with 1 of the 3 retraction cord medicaments. Dimensional accuracy was evaluated by comparing the average length of a line in the impressions to the standard die. Surface detail reproduction was evaluated by viewing the impressions under low-angle illumination at 10X magnification. Reproduction was considered satisfactory if 2 of 3 horizontal lines were reproduced continuously. The dies were also evaluated under the microscope before the impression was made. Results: The medicaments did not significantly affect the dimensional stability. Aluminum chloride and ferric sulfate had an adverse effect on surface detail reproduction. Epinephrine had no effect. Discussion: The changes in dimensional accuracy were within ADA guidelines, the surface detail reproduction was modified such that the impression would be considered clinically unacceptable. For optimal results, care must be taken to remove all traces of these retraction cord medicaments prior to recording of a polyvinyl siloxane impression.