Surface detail reproduction with new elastomeric dental impression materials

Objectives: To compare the surface detail reproduction ability of 2 polyethers, 1 polyether-polyvinyl siloxane (PVS) hybrid, and 1 polyvinyl siloxane reference impression material when impressions of prepared dentin are made, and to determine the wettability of the nonset and set impression materials. Method and Materials: Impressions from air-dried or wet dentin surfaces were made with the light-bodied impression materials P2 Polyether (P2L), Impregum Garant L DuoSoft (IMP), the hybrid-type Fusion/Senn Light (SEN), and the PVS Flexitime Correct Flow (FLE). Roughness (Rz, Ra) was determined on 5 dentin specimens and 5 impressions (dry or wet) for each material. Data were analyzed using ANOVA and Duncan's test (a .05). Wettability with water of nonset and set impression materials was recorded with an optical contact-angle measuring device. The set materials' wettability was determined on dry surfaces and after rinsing with water. Results: Differential dentin surface reproduction with IMP, SEN, and FLE was between -2 and +2 µm (Rz), and -0.2 and +0.2 µm (Ra). Curing of P2L on dentin was inhibited. The contact angle of nonset IMP was less than 45 degrees, and initial angles for nonset SEN, FLE, and P2L were greater than 90 degrees. Early contact angles on rinsed FLE, P2L, and SEN were greater than 90 degrees. Angles on set IMP were consistently between initial 75 degrees and final 55 degrees. Conclusion: IMP, SEN, and FLE reproduce prepared dentin accurately, whereas P2L does not cure on dry or wet dentin. All materials have a reasonable potential of wetting moist surfaces. Keywords: contact angle, impression material, polyether, surface detail reproduction, polyvinyl siloxane, wettability