Objectives: To evaluate and compare the accuracy of four different impression materials utilized in final impressions taking in mandibular edentulous cases using the Extra-oral digital scanning of impressions with EXOCAD software.
Materials and Methods: Twenty middle-aged patients were selected, with completely edentulous arches. For each patient, four different mandibular final impressions were obtained using four different impression materials namely, 1. Zn/O Eugenol, 2. Rubber Base single-step, 3. Silginat 4. Monophase impression materials. All four impressions were scanned using an Extra-oral scanner (Medit T710 Extra-oral laboratory Scanner). Two measurements were taken for each virtual cast and compared.
One-way ANOVA test and Tukey's post hoc test for multiple comparisons of measurements were used. Generally, there were no statistically significant differences in measurements.
Conclusions: Zn/O and Eugenol have always been considered the gold standard of secondary impression materials for completely edentulous ridges. This study concluded that the more recent, Rubber Base, Silginat, and Monophase impression materials proved to possess equivalent accuracy.