Sulcus depth reproduction with polyvinyl siloxane impression material: effects of hydrophilicity and impression temperature.

OBJECTIVE

To determine the sulcus penetration ability of hydrophilic and hydrophobic polyvinyl siloxane (PVS) impression materials by impression technique, temperature, and sulcus width.

METHOD AND MATERIALS

Hydrophilic Flexitime (FLE; Heraeus Kulzer) and its hydrophobic counterpart (EXP) without surfactant were investigated, using light (L), monophase (M), and heavy (H) consistencies. A truncated steel cone surrounded by a 2-mm-deep and 50-, 100-, or 200-microm-wide sulcus, simulating the gingival tissue with agar, served as the test model. Impressions were made with single-mix (L or M) and double-mix (LM or LH) techniques at 23 degrees C and 37 degrees C, respectively. The reproduced sulcus heights were measured with a 3D laser scanner. Data were analyzed by ANOVA and Tukey HSD (P < .05).

RESULTS

Irrespective of sulcus widths and temperature FLE-L penetrated deepest (> 1.9 mm); FLE-M, -LM, and-LH reproductions were shorter with narrow sulci. Reproductions of 50- and 100-microm sulci with EXP-L were shallower than with FLE-L. The shortest reproduction was, however, greater than 1.6 mm.

CONCLUSIONS

In spite of some significant differences found in sulcus-reproducing ability with hydrophilic and hydrophobic impression materials applied at different impression-making temperatures and with different techniques, the practical relevance is limited.