RESUMO
BACKGROUND: Surface detail reproduction (SDR) and dimensional stability of elastomeric impression material play a crucial role in fixed prosthodontics. AIM AND OBJECTIVES: The aim of this study was to compare the effect of chemical disinfection on SDR and dimensional stability of polyvinyl siloxane (PVS) and polyether (PE) with a new vinyl polyether silicone (VPES) elastomeric impression material. MATERIALS AND METHODS: A stainless steel mold was made to fabricate the study specimens for nonaqueous PVS, PE, and VPES elastic dental impression materials. Single mix impression techniques with light- and heavy-body consistency of all three materials were used to prepare the test specimens. The specimens were immersed in glutaraldehyde (Cidex) 2.45% and sodium hypochlorite (Hypo) 3.0% disinfection for 15 min (T1) and 12 h (T2) immersion after which dimensional stability and SDR were recorded using stereomicroscope and digital Vernier caliper. STATISTICAL ANALYSIS: The data were analyzed using the one-way ANOVA, paired t-test, Kruskal-Wallis test, and Wilcoxon signed-rank test. RESULTS: Dimensional stability at the T2 time interval showed a highly significant difference for control and glutaraldehyde groups (P < 0.001), whereas a statistically significant difference for Hypo group (P < 0.05). SDR of the three materials when compared at T1 time interval showed a statistically significant difference (P = 0.015). A comparison between two disinfectants at T1 time interval revealed a highly significant difference (P < 0.001), while at T2 interval significant difference was obtained (P = 0.009). CONCLUSION: VPES impressions display acceptable dimensional stability and SDR for clinical use with immersion disinfection. Although some statistically significant differences in linear dimensional stability and semidefinite programming were observed among VPES, PE, and PVS, but the clinical impact of these differences is minor considering the overall accuracy of casts which was high.
