Comparative In Vitro Analysis of Fracture Toughness and Flexural Strength in Interim Fixed Partial Dentures Reinforced With Various Nanofibers

Aim To evaluate and compare the fracture toughness and flexural strength of interim fixed partial dentures reinforced with carbon, glass, and Kevlar nanofibers. Materials and methods This study explored the effect of reinforcing poly methyl methacrylate with carbon, glass, and Kevlar fibers on its fracture toughness and flexural strength. A total of 120 samples were prepared, divided into two groups of 60 samples each, with one group tested for fracture toughness and the other for flexural strength. Each group of 60 samples was further subdivided into four equal subgroups, consisting of carbon, glass, Kevlar, and control groups (no reinforcement). The samples were tested using a universal testing machine, and the results were analyzed statistically. Results The normality of the continuous data was assessed using the Kolmogorov-Smirnov and Shapiro-Wilk tests. Continuous data were presented as mean and standard deviation. ANOVA was employed to determine significant differences in means across the groups, and the Post Hoc Bonferroni test was used for intergroup comparisons. A p-value of less than 0.05 was considered statistically significant. Kevlar fibers showed the highest mean value for fracture toughness (734.81 ± 58.22 MPa·m1/2), while glass fibers had the highest mean value for flexural strength (1.20 ± 0.05 MPa). Conclusion Kevlar fibers demonstrated greater fracture toughness compared to glass and carbon fibers. In terms of flexural strength, glass fibers exhibited the highest values, followed by Kevlar, with carbon fibers showing the lowest. The group without any reinforcement had the lowest values for both fracture toughness and flexural strength.