A Precision Analysis of Dimensional Accuracy of Three Recent and Improved Alginates with A Commonly Used Addition Silicone - An In Vitro Study

Aim : The present study was conducted to evaluate the dimensional accuracy of three commercially available improved alginate impression materials , two precision and one regular with that of a polyvinyl siloxane impression material . Here, the accuracy of tested impression materials was evaluated indirectly through recovered gypsum casts . Materials and methods : Here , the local accuracy pertains to dimensions measured only on the custom made metal die in the typhodont i.e. occluso-gingival, mesio-distal and bucco-lingual dimensions i.e. the dimensions in a small circumscribed area on metal die whereas general accuracy pertains to the measurement of two bigger dimensions which are : cross-arch and anteroposterior , therefore this study was taken up to evaluate and compare the dimensional accuracy , both local and general , of three improved alginates ( two high precision and one regular ) and one polyvinyl siloxane elastomeric impression material . Results : This study showed that within the group of improved alginates , Septalgin brand of test impression material was in closest resemblance with polyvinyl siloxane test impression material in dimensional accuracy followed by Neocolloid and Hydrogum brands of alginate test impression materials . Conclusion : The general accuracy of Neocolloid and Septalgin test impression materials was comparable to Polyvinyl siloxane test impression material . The local accuracy of Polyvinyl siloxane test impression material was better than all improved alginate test impression materials. Within the group of improved alginates , Septalgin brand of test impression material was in closest resemblance with polyvinyl siloxane test impression material in dimensional accuracy followed by Neocolloid and Hydrogum brands of alginate test impression materials . The general accuracy of Neocolloid and Septalgin test impression materials was comparable to Polyvinyl siloxane test impression material.