Related Experiment Videos
The ratio between vertical and horizontal changes of impressions
1Department of Restorative Dentistry, Hebrew University- Hadassah School Dental Medicine, Jerusalem, Israel.
Journal of Oral Rehabilitation
|January 1, 1993
Summary
This study analyzed how impressions change horizontally and vertically using a mandibular stock tray. The Poisson's ratio for rubber materials was found to be 0.44, indicating a constant strain ratio for specific impression techniques.
Area of Science:
- Dental Materials Science
- Biomechanical Engineering
Background:
- Accurate dental impressions are crucial for prosthodontic restorations.
- Understanding dimensional changes in impression materials is key to predictable outcomes.
Purpose of the Study:
- To theoretically and experimentally analyze the relationship between horizontal and vertical dimensional changes in impressions made with a mandibular stock tray.
- To determine the Poisson's ratio of the impression material under specific conditions.
Main Methods:
- Theoretical analysis of dimensional changes based on material properties and die dimensions.
- Experimental impression taking using a mandibular stock tray.
- Calculation of Poisson's ratio from measured dimensional changes.
Main Results:
- A theoretical model was developed to relate horizontal (delta X) and vertical (delta Z) dimensional changes.
- The experimental Poisson's ratio (mu) was calculated as 0.44, consistent with rubber materials.
- The ratio of vertical to horizontal strain was found to be constant for a given impression technique.
Conclusions:
- The study provides a theoretical framework and experimental validation for understanding the dimensional stability of mandibular impressions.
- The findings are relevant for selecting appropriate impression materials and techniques in dental practice.
- The constant strain ratio highlights the predictability of material behavior under specific conditions.