Comparative Evaluation of Effect of Altered Pouring Time on The Dimensional Accuracy of Alginate Replacement Materials: An In-vitro Study

Abstract

Aims: The present study aimed to evaluate and compare the dimensional accuracy of alginate replacement material with a traditional PVS impression material at different pouring intervals.

Methods and Material: In this in-vitro study, sample size estimation was done using G*power software (version 3.1.9.2), at 95% confidence interval. A total of 40 impressions samples were made. Stainless steel dies were used to make impressions in accordance with ADA specification 19 using Alginate alternate PVS, Xantasil (Material A, Test group n=20) and conventional light body PVS, Express XT (Material B, Control group n=20). This 20 Impressions in each group were further divided into 4 groups (n=5) and poured after one hour(α), 24 hours (β), seven days (γ) and fourteendays (δ) time intervals. After obtaining the casts following the respective storage times, dimensionalchanges were measured using aToolmaker’s travelling microscope (α=0.05). Statistical analysis was performed using Paired T-test with post hoc Dunnett to compare the dimensional accuracy at different time intervals.

Results: The dimensional stability of impressions and accuracy of casts was least when poured at 14 days, the changes in both materials at all given time intervals was clinically insignificant (less than 0.5%).There was no significant difference in both impression materials at all pouring intervals (Paired T-test with post hoc Dunnett; p>0.001).

Conclusions: The results indicate that Xantasil can be used as a substitute to conventional polyvinyl siloxane material. Statistical significance of delayed pouring of xantasil up to 14 days was comparable to conventional PVS.