Influence of Different Finish Line Types on the Penetration Properties of Elastomeric Impression Materials

Abstract

Introduction: The objective of this study was to determine the penetration ability of elastomeric impression materials affected by abutment finish line configurations with a simulated gingival sulcus model. Methods: The gingival sulcus model was simulated using agarose gel and milled abutment models. Twenty impressions of each finish line (feather-edge, mini-chamfer, chamfer, heavy chamfer, and radial shoulder) were made. Four elastomeric impression materials were used for the two-step double-mixed, double-impression technique, consisting of polysulfide, polyvinylsiloxane, polyether, and vinylsiloxanether (N=120). The extension of impression that flowed into the simulated gingival crevices was measured under a stereomicroscope by using image analysis software. Results: Two-way analysis of variance revealed statistically significant main effects and an interaction between finish line type and impression material type (p<0.05). The radial shoulder showed significantly greater penetration than the other finish lines for polyvinylsiloxane, polyether, and vinylsiloxanether (p<0.05). Conclusions: The type of finish line influences the ability of elastomeric impression materials to penetrate within a simulated gingival sulcus model. The penetration ability of elastomers tends to increase due to the increasing width of the finish line. Among all the materials, polyether has the greatest potential to penetrate through the narrow gingival sulcus.