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Updated: Jun 10, 2026
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Measuring the Complete-arch Distortion of an Optical Dental Impression
Published on: May 30, 2019
Accuracy of impression techniques for an implant-supported prosthesis
Marcelo Antonialli Del'Acqua1, Alejandro Muñoz Chávez, Marco Antonio Compagnoni
1Araraquara University Center-UNIARA, Araraquara, São Paulo, Brazil. mdelacqua@ig.com.br
Summary
The modified squared and index impression techniques for implant-supported prostheses showed greater dimensional accuracy than the squared technique. These findings aid in selecting optimal impression methods for dental restorations.
Area of Science:
- Dental Materials Science
- Prosthodontics
- Biomaterials Engineering
Background:
- Accurate impressions are crucial for fabricating well-fitting implant-supported prostheses.
- Existing impression techniques vary in their dimensional stability, potentially impacting prosthetic fit and patient outcomes.
Purpose of the Study:
- To compare the dimensional accuracy of a stone index, squared impression copings, and modified squared impression copings for implant-supported prostheses.
Main Methods:
- An in vitro study utilized a master cast with four implant-abutment analogs and a passive framework.
- Vinyl polysiloxane impression material was employed with three techniques: index (I), squared (S), and modified squared (MS) (n=5 each).
- Measurements of abutment/framework interface gaps were analyzed using stereomicroscopy and specialized software.
Main Results:
- The master cast exhibited a mean gap of 31.63 µm.
- Impression groups showed mean gaps: index (45.25 µm), squared (96.14 µm), and modified squared (51.20 µm).
- No significant difference in accuracy was found between the index and modified squared techniques.
Conclusions:
- The modified squared and index impression techniques yielded more accurate casts compared to the squared technique.
- These findings suggest improved clinical applicability of the modified squared and index methods for implant prosthodontics.
