Comparative study of two impressions techniques

Abstract

Background & Aim: A successful dental restoration is mainly dependent on the accuracy of the dental impression. For a dentist it is very important to select a suitable impression technique using appropriate materials to get a model as accurate as possible.

There are many techniques to make dental impression and each one of them had its own advantages and drawbacks. However, the technique that gives 100% accuracy is yet to be developed.

This study aimed to compare between traditional and coping dental impression techniques regarding: marginal fit of all metal cores made from both techniques and patient comfort.

Materials and Methods: The research sample included (16) posterior tooth for (16) patient were prepared with radial shoulder finish line (1) mm to receive metal cores made by CAD_CAM technique.

Two separate impressions: traditional and coping dental impression techniques were made for each prepared tooth by using condensation silicone, patient comfort were measured and registered in a special form. The laboratory procedures were executed for every impression to obtain tow metal cores, which were tried in patient’s mouth.

The marginal and internal fit were measured by replica technique with an optical microscope (10-x magnification).

Suitable statistical studies were made (T student and Mann_Whitney) to obtain the results.

Results: No statistically significant differences were found in the marginal and internal fit of two metal cores made from traditional impression technique and coping impression technique and the results were in (μm) unit:

Traditional impression technique: marginal fit: 59.688

Coping impression technique: marginal fit: 59.844

The coping impression technique was statistically significantly more comfortable for patients than the traditional impression technique

Conclusions: Within the limits of this study, the coping impression technique is considered similar to the traditional impression technique regarding the accuracy of marginal fit. Furthermore, it is more comfortable for patients.