The Journal of Contemporary Dental Practice

Register      Login



Volume / Issue

Online First

Related articles

VOLUME 20 , ISSUE 8 ( August, 2019 ) > List of Articles


Comparison of Dimensional Accuracy of Stone Models Fabricated by Three Different Impression Techniques Using Two Brands of Polyvinyl Siloxane Impression Materials

Sakshi Garg, Shashikala Jain, Rajnish Aggarwal, Sunita Choudhary, Nandalur K Reddy

Keywords : Dimensional accuracy, Monophase, One step putty wash, Polyvinyl siloxane, Two step putty wash

Citation Information : Garg S, Jain S, Aggarwal R, Choudhary S, Reddy NK. Comparison of Dimensional Accuracy of Stone Models Fabricated by Three Different Impression Techniques Using Two Brands of Polyvinyl Siloxane Impression Materials. J Contemp Dent Pract 2019; 20 (8):928-934.

DOI: 10.5005/jp-journals-10024-2629

License: CC BY-NC 4.0

Published Online: 01-12-2019

Copyright Statement:  Copyright © 2019; The Author(s).


Aim: The aim of this study is to check the dimensional precision of stone models made by two different brands of polyvinyl siloxane impression materials using the monophase, one-step, and two-step putty/light-body impression techniques. Materials and methods: A metal model, having two crown preparations, was fabricated. With each technique, 40 impressions were made using two types of polyvinyl siloxane impression materials (Aquasil and Virtual). A total of 240 impressions were made with both the polyvinyl siloxane impression materials. Monophase impressions were made with a medium body using an acrylic custom tray. By simultaneous usage of putty and light-body, one-step impressions were made with a perforated metal stock tray. For two-step impressions, a 25–40 microns thick cellophane sheet spacer was used. The stone casts were obtained from the impressions of the stainless steel model. Three different dimensions (height, diameter, and inter-abutment distance) on these resultant stone casts were compared with the standard die. The accuracy of two different brands of impression materials was also compared. The results were then statistically analyzed. Results: The resultant casts obtained from the different impression techniques had significantly larger dimensions in height and diameter, but smaller dimensions were observed for the inter-abutment distance. Larger deviation in resultant casts was observed in the monophase than one-step impression technique and the least deviation was observed in the two-step impression technique. Conclusion: The two-step impression technique produced the most accurate results in terms of the resultant casts. Out of the two different brands, Aquasil produced more fare results. Clinical significance: Adequate marginal adaptation, proper fit and least distortion of the castings, and the final prosthesis can be achieved by using the adequate impression technique and impression material.

  1. Henry PJ, Harnist DJR. Dimensional stability and accuracy of rubber impression materials. Aust Dent Journal 1974; 162–166. DOI: 10.1111/j.1834-7819.1974.tb05033.x.
  2. Filiz K. Some properties of elastomeric impression materials used in fixed prosthodontics. J Islamic Acad Sci 1994;7(1):44–48.
  3. Hung SH, Purk JH, et al. Accuracy of one-step vs two-step putty wash addition silicone impression technique. J Prosthet Dent 1992;67(5):583–589. DOI: 10.1016/0022-3913(92)90151-Y.
  4. Chee WW, Donovan TE. Polyvinyl siloxane impression materials: a review of properties and techniques. J Prosthet Dent 1992;68(5): 728–732. DOI: 10.1016/0022-3913(92)90192-D.
  5. Mandikos MN. Polyvinyl siloxane impression materials: an update on clinical use. Aust Dent J 1998;43(6):428–434. DOI: 10.1111/j.1834-7819.1998.tb00204.x.
  6. Idris B, Houston F, et al. Comparison of the dimensional accuracy of one and two –step techniques with the use of putty/wash addition silicone impression materials. J Prosthet Dent 1995;74(5):535–541. DOI: 10.1016/S0022-3913(05)80358-0.
  7. Millar BJ, Dunne SM, et al. In vitro study of the number of surface defects in monophase and two-phase addition silicone impressions. J Prosthet Dent 1998;80(1):32–35. DOI: 10.1016/S0022-3913(98) 70088-5.
  8. Kumar S, Yadav D, et al. A comparative evaluation of tray spacer thickness and repeat pour on the accuracy of monophasic polyvinyl siloxane impression material: In vitro study. Indian J Dent Res 2014;25(2):184–187. DOI: 10.4103/0970-9290.135916.
  9. Franco EB, da Cunha LF, et al. Effect of storage period on the accuracy of elastomeric impressions. J Appl Oral Sci 2007;15(3):195–198. DOI: 10.1590/S1678-77572007000300008.
  10. Lewinstein I. The ratio between vertical and horizontal changes of impressions. J Oral Rehabil 1993;20:107–114. DOI: 10.1111/j.1365-2842.1993.tb01520.x.
  11. Franco EB, da Cunha LF, et al. Accuracy of Single-Step vs 2-Step Double-Mix Impression Technique. Int Sch Res Net Den 2011; 1–5.
  12. Mahdi NA. Comparative evaluation of the dimensional accuracy of different putty-wash techniques using additional silicon impression material-In Vitro study. Journal of Al Rafidain University College 2016; 141–161.
  13. Nissan J, Gross M, et al. Effect of wash bulk on the accuracy of polyvinyl siloxane putty-wash impressions. J Oral Rehabil 2002;29:357–361. DOI: 10.1046/j.1365-2842.2002.00820.x.
  14. Faria AC, Rodrigues RC, et al. Accuracy of stone casts obtained by different impression materials. Braz Oral Res 2008;22(4):293–298. DOI: 10.1590/S1806-83242008000400002.
  15. Caputi S, Varvara G. Dimensional accuracy of resultant casts made by a monophase, one-step and two-step, and a novel two-step putty/light-body impression technique: an in vitro study. J Prosthet Dent 2008;99:274–281. DOI: 10.1016/S0022-3913(08)60061-X.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.