Deformation Resistance of Palatal Plate Connectors in Removable Partial Dentures

Oana Cella Andrei,Adina Magdalena Bunget,Ioana Tarlungeanu,Mihai Burlibasa,Catalina Farcasiu,Adriana Bisoc,Ruxandra Margarit,Magdalena Natalia Dina,Livia Alice Tanasescu

doi:10.37358/mp.20.1.5328

Abstract

The aim of our study was to evaluate the deformation resistance of two palatal plate type connectors of removable partial dentures and to make a comparison between the reduced palatal plates and the large ones, in terms of bending resistance during function. We tested 10 maxillary class I Kennedy removable partial dentures made for real clinical cases and duplicated their connectors, 5 of each type. A Universal Loading Machine was used to apply a bilateral progressive force to the PM2-M1 area until the samples bended, recording the force value at which the first change occurred. The results were analyzed using the ANOVA method. For the reduced palatal plate group, the minimum bending force value was 1584 N, the maximum bending force value being 2920 N. For the large palatal plate group, the minimum bending force value was 3150 N, the maximum value being 3380 N. Statistical analysis of data using the ANOVA method shows that the results are statistically relevant, with a p value of 0,001031 (p[0,05). The results showed that decreasing the width of the palatal plate can have a significant effect on the deformation resistance of the major connector and can affect its rigidity; in clinical practice, these results can help dentists to use alternative appropriate design methods of increasing the rigidity of reduced palatal plates, in order to protect both the remaining structures and the acrylic components of the dentures during the years of its functioning. Keywords: palatal plate, removable partial denture, deformation resistance

Highlights

Palatal plate type connectors of removable partial dentures (RPD) cover half or more of the palate contributing to the wide distribution of stresses coming from the acrylic parts of the removable partial dentures
The aim of this study is to evaluate the deformation resistance of the palatal plate type major connectors in maxillary class I Kennedy removable partial dentures, comparing the reduced plate with the large one, and to analyze the differences in bending resistance between the different widths of the palatal strap, in order to help dentists to choose the best way to design these connectors
The study was carried out on a number of 10 upper class I Kennedy removable partial dentures, with saddles and artificial teeth made of thermoplastic PMMA, made for 10 real clinical cases, all having palatal plate type major connectors that were duplicated for the experiment

Summary

Introduction

Palatal plate type connectors of removable partial dentures (RPD) cover half or more of the palate contributing to the wide distribution of stresses coming from the acrylic parts of the removable partial dentures (in our cases, artificial acrylic teeth and saddles). Their role is to connect metallic and acrylic parts in order to ensure support, retention and stabilization of the denture; one of their most important features is rigidity during the entire period of the denture’s function. In order to remain rigid during the entire functioning period of the denture, the width of the palatal plate is classically considered to have to be designed

Objectives

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Results