Dimensional Optimization of Graphene-Modified Polymethyl Methacrylate Material Used as an Aesthetic Removable Partial Denture Clasp Material

Abstract Objective  Although graphene-modified polymethyl methacrylate material is a good candidate for partial denture clasp material, it lacks adequate strength. Therefore, the study aims to assess the optimal dimension of this nanomodified material required for such an application. Materials and Methods  A parametric finite element analysis study was conducted on 54 clasp 3D models at two displacement levels (0.25–0.5 mm) placed 3 mm from the clasp tip. The clasp models were categorized based on the dimensions into A, B, and C (3 subgroups in each) and six tapers from the tip to the base (0.5–1). Both reaction force in (N) and maximum principal stress in (MPa) were recorded and analyzed. The study was validated using the mechanical tester after digital manufacturing of the clasp specimens that showed satisfactory results. Statistical Analysis  The correlations between width and thickness against reaction force and maximum principal stress were checked by a statistical analysis software package (SPSS version 22; IBM Corp., Armonk, New York, United States). Data of the reaction force demonstrated nonparametric behavior, as tested by the Kolmogorov–Smirnov test. Accordingly, Spearman's rho test for correlation was used. In contrast, the maximum principal stress data showed normal distribution, as tested by the Kolmogorov–Smirnov test. Thus, Pearson's test of correlation was applied. Results  The results demonstrated the best retention force values, considering aesthetics, in subgroups C3 (taper 0.6), C3 (taper 0.8), and B3 (taper 1). The maximum principal stress results showed the highest values in group C followed by group B and then group A. Positive correlations were calculated between thickness and width versus reaction force and maximum principal stress. The correlation coefficient value between thickness and reaction force was 0.699 and that between width and reaction force was 0.621, while the correlation coefficient between thickness and maximum principal force was 0.899 and that between the width and maximum principal force was 0.740. Conclusion  It could be concluded that the studied material might be recommended as a valid aesthetic clasp material. Both clasp thickness and width showed a positive correlation with the clasp retention force with more impact by the thickness.