In-vitro analysis of stress dynamics in polyamide and metal acrylic distal extension removable partial dentures.

Background: This study aimed to determine and compare the stresses transmitted by metal acrylic and polyamide removable partial dentures (RPDs) on free-end saddle areas.

Methods: Twenty metal acrylic and polyamide removable partial dentures were made. The stresses transmitted on the free end saddle area were determined and compared by using the strain gauge resistance method, in which sensors were installed in the epoxy resin cast. The load was applied on removable partial dentures with the underlying cast through the universal testing machine. Data was collected through the connected strain meter and computer. The analysis was done using ANSYS version 15, and the results were analyzed.

Results: The polyamide distal extension removable partial dentures transmit higher but even stresses on the free end saddle area compared to metal acrylic distal extension RPDs. The forces transmitted by polyamide distal extension base RPDs distribute an even load on the ridge, whereas metal acrylic distal extension base RPDs distribute an uneven load on the ridge. P value equal to and < 0.05 was considered significant, and our results showed insignificant statistical differences.

Conclusion: Stress distribution in polyamide distal extension removable partial dentures is even compared to metal acrylic distal extension removable partial dentures. Even force distribution is less damaging to the bone and surrounding tissues.