On functional strain in some fixed and removable partial dentures. An experimental in vitro study

Area of Science:

• Dental prosthetics
• Biomaterials engineering
• Biomechanics

Background:

• Fixed and removable partial dentures are common restorative solutions.
• Combining these prostheses can offer improved function and stability.
• Understanding the biomechanical behavior of such combined systems is crucial for clinical success.

Purpose of the Study:

• To investigate the mechanical deformation of a combined fixed and removable partial denture (RPD) system.
• To simulate the mechanical properties of supporting oral tissues using artificial materials.
• To analyze the influence of the RPD on the deformation of the fixed reconstruction under laboratory loading conditions.

Main Methods:

• Fabrication of an 11-unit fixed maxillary reconstruction with cantilever pontics.
• Fabrication of a removable partial denture (RPD) with a palatal bar, retained by precision attachments.
• Construction of a laboratory model simulating biologic supporting tissues.
• Utilizing a strain-gauge technique to measure deformation in both components under various loading scenarios.

Main Results:

• The fixed dental appliance exhibited more extensive and complex deformation when the RPD was excluded.
• Deformation patterns differed significantly with and without the RPD in place.
• The laboratory model effectively simulated the mechanical behavior of the biological support.

Conclusions:

• The removable partial denture (RPD) plays a significant role in stabilizing the fixed maxillary reconstruction.
• Excluding the RPD leads to increased and more complex deformation of the fixed prosthesis.
• This study underscores the biomechanical benefits of combining fixed and removable components in complex dental restorations.