A three-dimensional finite element analysis of Aramany class I obturator fabricated with different alloys

Abstract

Aim: The aim of the research was to develop a model that accurately represents an Aramany class I defect and its obturator prostheses fabricated with cobalt–chromium alloy and titanium alloy to compare the deflection and the stress distribution in the rehabilitated area. Materials and Methods: Aramany class I defect and the obturator prostheses were generated geometrically using ANSYS 14.5; both were superimposed on each other to mimic the prostheses and the maxilla as one unit. Meshing of models was carried out using hypermesh software and materialistic properties were assigned. The 120 newton load was constituted on the teeth in different directions. Statistical Analysis Used: Statistical analysis of Finite element was not possible. Self-explanatory decoding results in the software were used. Results: The stress distribution and deflection executed by ANSYS provided results that enabled the tracing of Von Mises stress and deflection field in the form of color-coded bands with values in mega pascal. Conclusions: The study shows that Von Mises stresses are higher for the frame work fabricated with cobalt–chromium alloy compared to titanium alloy. The framework made of titanium alloy showed more deflection than cobalt–chromium alloy.

Biomechanical Stress in Obturator Prostheses: A Systematic Review of Finite Element Studies

“…One of them evaluated the stress in congenitally unilateral palatal cleft scenario [25], one used mainly in vivo approach with no interpretation in the result and discussion sections regarding FEA [23], and four different studies were duplicated in their methodology and results [24,26], so we chose the earlier studies [13,27]. Finally, 13 articles were recruited for this review [13,[27][28][29][30][31][32][33][34][35][36][37][38]. The number of primary surveyed articles, number of excluded articles, reasons for exclusion, and the final recruited articles are shown in Figure 1.…”

“…In the studies that evaluated dentulous scenarios of Aramany's class I and class II palatal defect, they found that the maximum stress concentration is located around the cervical half of the roots of the teeth next to the resection, central, and lateral incisors of the contralateral side in class I or canine in [13,30,35]. The cobalt-chromium alloy was found to produce more stress on the remaining teeth, when used as a major connector and retainers, compared to titanium alloy which showed more flexibility.…”

“…The cobalt-chromium alloy was found to produce more stress on the remaining teeth, when used as a major connector and retainers, compared to titanium alloy which showed more flexibility. Desbite this, due to titanium decreased rigidity, the major connector is deflected toward the areas where the force is applied [30,35]. The use of Vertex polymer as a retainer with an occlusal plate on the main abutment teeth was found to reduce stress on the teeth without compromising the stability of the prosthesis [24].…”

“…Exclusion criteria (1) The studies conducted between January 2010 and December 2020 (2) Studies conducted in the English language (3) In vitro mathematical studies (4) Studies conducted only on partial and complete removable maxillofacial obturators (5) The case with surgical maxillary defect (6) Studies used only FE methods to predict the distribution of the stress and displacement in MFP 3 BioMed Research International that assessed the differences in displacement between singleand two-piece closed hollow-bulb obturators [29]. In the reviewed studies, the stress was estimated in the prostheses for partially edentulous scenarios [13,27,29,30,32,[34][35][36][37], while in another it was examined in completely edentulous scenarios [25,28,31,33,38]. Six of the 13 studies reviewed in the current review, examined the influences of implant/s on the distribution of stress in the prostheses.…”

“…The main reason for this is owing to the variety of the occlusal forces that can be found in the population, which are dependent on gender, age, general health, natural dentition, and anterior or posterior teeth. However, the mean maximum force 120-150 N were selected, either individually or collectively, in most of the reviewed studies, as it considers the mean maximum force for patients with remaining natural teeth and wearing removable obturator prostheses [13,29,30,32,35,36].…”