A New Proposal for Calibrated Gauges for Removable Partial Dentures: A Finite Element Analysis

Area of Science:

• Biomaterials Science
• Dental Engineering
• Computational Mechanics

Background:

• Removable partial dentures (RPDs) are crucial for restoring function and aesthetics in patients with missing teeth.
• Optimizing RPD retention and minimizing stress on abutment teeth are key clinical challenges.
• Current clinical practices utilize varying undercut gauges, with limited data on the optimal choice.

Purpose of the Study:

• To evaluate stress distribution in planned RPDs using novel 0.3 mm and 0.35 mm calibrated undercut gauges.
• To compare the biomechanical performance of these new gauges against existing 0.25 mm and 0.5 mm gauges.
• To assess the impact of different undercut depths on the periodontal ligament of abutment teeth.

Main Methods:

• Three-dimensional (3D) finite element analysis (FEA) was employed using CAD software (InVesalius, Rhinoceros, SolidWorks).
• Kennedy class-I edentulous models with RPDs were created and meshed in HyperMesh 2019.
• Axial loading of 280 N unilaterally was applied to molar and premolar abutments, with stress maps generated using OptiStruct 2019 and HyperView 2019.

Main Results:

• The 0.30 mm and 0.35 mm gauges exhibited stress distributions comparable to the 0.25 mm gauge (gold standard).
• No significant adverse effects on biological structures were observed with the 0.30 mm and 0.35 mm gauges.
• The 0.5 mm undercut gauge resulted in increased traction forces within the periodontal ligament of abutment teeth.

Conclusions:

• The 0.35 mm undercut gauge demonstrates potential for improved RPD retention and favorable stress distribution.
• A 0.5 mm undercut may exceed the necessary retention for cobalt-chromium (CoCr) retainers, potentially causing harm.
• Further simulation and clinical validation are warranted to confirm the efficacy of the 0.35 mm undercut gauge.