A comparative study evaluate dimensional accuracy of newly poly vinylsiloxanase elastomeric impression material at different times and conditions

الملخص EN

Background : elastomeric impression materials are widely used registration of teeth and oral surrounding tissues, these materials have been developed newly through manufacture productions, dimensional accuracy is one of the most important feature showed be examined for each material at different conditions to evaluate material properties, a study therefore was undertaken to measure dimensional accuracy of newly elastomeric material at different times using different die stone types. Materials and methods : fifty impression samples from two different elastomeric materials were taken of metal block (ADA) block conforming the American dental association specification no.

(19) for impression materials, using two different types of die stone for each .Dimensional accuracy was measured by comparing the average length of middle horizontal line in each impression to the corresponding line in the metal die by using digitalized veirnea after 24 hr.

of pouring,1 week.

And after 1 month..

Surface roughness also measured by using profilometer, porosity of surface material, dries and moist conditions of impression materials were also discussed. Results : dimensional accuracy under dry and moist conditions, surface roughness, surface porosity, and effect of different times of measurement procedures; all demonstrate significant differences for both types of silicon impression materials at the two different types of dental stone.

Additional silicon material showed a non- significant difference in dimensional accuracy with type II dental stone, while both types of silicon materials showed anon- significant difference in surface roughness test for type III dental stone.

The newly extra light silicon material showed also a non-significant difference for only type II dental stone after 24 hr.

time of measurement. Conclusion : based on the results obtained from this study there was a significant difference in dimensional accuracy, surface roughness, porosity, and moist condition effect measurements between different silicon impression materials with their different types of die stone .these variations gave us an idea that not all materials from the same category and same type should result in same properties and surface features.