Accuracy of three polyvinyl siloxane putty-wash impression techniques

Area of Science:

• Dental materials science
• Prosthodontics
• Impression techniques

Background:

• The accuracy of dental impression techniques significantly impacts the fit and success of cast restorations.
• Variations in impression methods can lead to discrepancies in the final prosthodontic outcome.

Purpose of the Study:

• To evaluate and compare the accuracy of three distinct putty-wash impression techniques.
• To determine the most precise method for fabricating dental stone dies using polyvinyl siloxane material.

Main Methods:

• Three putty-wash impression techniques were tested: 1-step, 2-step with 2-mm relief, and 2-step with a polyethylene spacer.
• Impressions were made from a stainless steel master model with three crown abutment preparations.
• Accuracy was quantified by measuring six intra- and inter-abutment dimensions on poured stone dies.

Main Results:

• Statistically significant differences (P <.001) were observed among the three impression techniques for all measured dimensions.
• The 2-step technique with 2-mm relief demonstrated significantly smaller overall discrepancies compared to the 1-step and polyethylene spacer methods.

Conclusions:

• The 2-step, 2-mm relief putty-wash impression technique using polyvinyl siloxane is the most accurate for producing stone dies.
• This technique provides enhanced precision for dental laboratory fabrication of cast restorations.