On Comparing Two Different Tray-Holding Techniques for Edentulous Maxillary Impressions

Area of Science:

• Dentistry
• Biomaterials Science
• Biomechanical Engineering

Background:

• Accurate maxillary impressions are crucial for fabricating well-fitting dentures.
• Conventional impression techniques rely on clinician-applied manual pressure, which can introduce inaccuracies.
• Understanding tissue behavior during impression material setting is essential for optimizing techniques.

Purpose of the Study:

• To compare three-dimensional (3D) tissue displacements in the maxilla during the setting phase of impression materials.
• To evaluate two tray-holding techniques: clinician manual pressure versus patient occlusal pressure.

Main Methods:

• Ten edentulous patients participated in the study.
• Maxillary impressions were recorded using both manual and occlusal pressure techniques.
• An optical 3D measurement system was employed to compare the resultant maxillary casts and analyze tissue displacements.

Main Results:

• The junction of the hard and soft palates served as a rotation center during impression making.
• Vertical tissue displacements were significantly lower and located more posteriorly when using patient occlusal pressure.
• Manual impression techniques resulted in vertical displacements primarily in the anterior two-thirds of the palate.

Conclusions:

• Employing patient's occlusion for tray holding during maxillary impressions may be a preferred technique.
• This method potentially leads to more accurate impressions by minimizing undesirable vertical tissue displacements.
• Further research could explore the long-term clinical implications of this technique.