Accuracy of casts obtained from putty wash impression material using different types of spacers - An Invitro Study

Abstract

Aim: The aim of this study was to evaluate the accuracy of casts obtained from two stage putty wash impression material employing three different types of spacers.

Setting and design: An in vitro comparison of accuracy of two stage putty wash impression using three different spacers

Material and method: A master metal die was fabricated to simulate a three unit fixed partial denture and a custom metal tray was made. Two stage putty wash was made using three different spacers-conventional polyethylene sheet, vacuum formed sheet and micropore tape. Fifteen impressions were made using each of the three spacers and casts poured. The resultant casts were assessed for dimensional accuracy using the coordinate measuring machine, with the master metal die as control. The data obtained were statistically analysed using one way ANOVA and Student t test.

Statistical analysis used: The data was subjected to statistical analysis using SPSS version 21.0 software. The intergroup comparison was done using sample t-test, and the study models were analyzed using ANOVA statistical analysis.

Results: The results obtained showed that casts obtained from two stage putty wash impression technique using the micropore tape spacer produced least dimensional variation of 0.20% at inter-abutment distance and -1.08%,-0.67% at intra-abutment distance 1 and 2 respectively when compared to other two spacers used.

Conclusion: Two stage putty wash impression technique using micropore tape spacer yielded casts that have better dimensional accuracy when compared to the conventional polyethylene spacer technique