Comparative evaluation of surface detail reproduction and dimensional stability of poly ether, polyvinyl siloxane and vinyl polysiloxane ether impression materials: An In Vitro study

Abstract

BACKGROUND: An accurate duplication of the patients hard and soft tissue is an significant. one to give a precise fitting cast restoration. Impression making an integral part of prosthetic dentistry. Development of material science has allowed integrating qualities of hydrophilic poly ether and hydrophobic polyvinyl siloxane into a newer hybrid material vinyl polysiloxane ether. The aim of this In vitro experiment is to compare the newer material vinyl polysiloxane ether with the poly ether and polyvinyl siloxane in terms of accuracy and dimensional stability. MATERIALS AND METHODS: Stainless steel dies with ADA specification 19 was made. Die has 3 horizontal and 2 vertical lines are used for taking impression. The horizontal lines are labeled one, two, and three. The horizontal line has a width of the 0.60 mm. Two cross-points at the junction of the vertical lines with line 2 were patent as x and x' serve. These lines were the beginning and end points of dimensions for dimensional accuracy. Accuracy was evaluated 30 minutes after making each impression stored in room Stainless steel dies with ADA specification 19 was made. Die has 3 horizontal and 2 vertical lines are used for taking impression. The horizontal lines are labeled one, two, and three. The horizontal line has a width of the 0.60 mm. Two cross-points at the junction of the vertical lines with line 2 were patent as x and x' serve. These lines were the beginning and end points of dimensions for dimensional accuracy. Accuracy was evaluated 30 minutes after making each impression stored in room temperature. Continuity of line of replication is measured. If at least 2 of the 3 horizontal lines were reproduced continuously between cross points, this impression was considered satisfactory. The specimens are poured with type IV gypsum product and allowed to set completely for 24 hours. Then dimensional stability was measured in the model by measuring the distance between the two lines and comparing the distance with the measurement of line on metal die which was used to make the impression. RESULTS: The mean value obtained for the vinyl polysiloxane ether light was 0.0 5370 and for medium was 0.05330. the mean value for light and medium bodied polyvinyl siloxane was 0.06370 and 0.07150 and the mean value for poly ether monophase was 0.06430 respectively. A 2-way ANOVA statistical analysis gave a significance of p=0.005 while the post- hoc test for inter group analysis gave a p value of > 0.05. CONCLUSION: The newer vinyl polysiloxane ether material showed good surface detail reproduction and Dimensional Stability among all five materials. Although these differences when compared to the master die were significant, such a small discrepancy between the five groups, in relation to the overall dimension can be considered clinically insignificant, such a small discrepancy between the five groups, in relation to the overall dimension can be considered clinically insignificant