Algitex Vs Neocolloid: A Comparative in Vitro Study of Linear Dimensional Change at Three Different Storage Period

Abstract

Aim: The aim of this study was to compare the dimensional stability of two different irreversible
hydrocolloid impression materials at three different storage periods.
Materials and Methods: A brass model representing maxillary edentulous ridge was used as a master
model in this study. Three customized abutments A, B, C were CAD/CAM machined to simulate full
veneer preparation. They were positioned on the master model one in the anterior region and two in the
posterior region on either side of the ridge. The center of the crosshair reference lines made on the
occlusal surfaces of abutments was used for measuring linear dimensional changes. A total of 60
impressions of the master model was made by all two irreversible hydrocolloids (Algitex and
Neocolloid) and stored in three different storage period of 30 minutes, 12 hours and 24 hours. The casts
were poured after three storage period with type IV gypsum product and the inter abutment distance
between the abutments were measured with the electronic vernier caliper.
Results: ANOVA analysis showed no significant differences (p< .05) at 30 minutes storage period
between two impression materials and a very high significant difference (p< .001) at 12 and 24 hours
storage periods.
Conclusion: The dimensional accuracy of the improvised alginates Neocolloid were greater than the
conventional Algitex in delayed pouring of the cast.