The effectiveness of hexagonal boron nitride as an additive in the enhancement of scleral acrylic resin properties subjected to artificial weathering

Background: A common material used to create ocular prostheses is scleral acrylic resin. However, this material's characteristics changed over time, necessitating the refabrication of the prosthesis. Numerous investigations were carried out to enhance these characteristics by adding nanoparticle reinforcement. Aims: This research attempted to assess the impact of hexagonal boron nitride nanoparticles (H-BN NPs) in a weight percentage of (0.050wt% and 0.075wt %) on the mechanical features of scleral acrylic resin (the impact strength, surface hardness and surface roughness) before and after being subjected to artificial weathering. Materials and Methods: 90 specimens were created and split into three groups, 30 for the impact strength test, 30 for the surface hardness test, and 30 for the surface roughness test, which is separated into 3 subgroups (n = 10) according to each test (Control group, 0.050 wt.%, and 0.075 wt.% modified groups). Specimen's microstructure and elemental examination for H-BN were quantified utilizing Izod's impact tester, Shore D hardness test machine, Profilometer device, field emission scanning electron microscope (FE-SEM), and energy dispersive x-ray (EDX) spectroscopy, respectively. Results: One-way ANOVA and post-hoc Tukey's tests were used to analyze the data; statistical significance was indicated by a p-value < 0.05. The FE-SEM test revealed that H-BN was equally distributed throughout the polymer matrix. A significant difference (p < 0.05) for impact strength and a non-significant difference effects were found regarding Shore D hardness and surface roughness before and after being subjected to weathering. Conclusion: H-BN--modified specimens exhibited superior resistance to mechanical degradation compared with the control group. These findings support the potential of H-BN NPs as an effective reinforcing additive for ocular prosthetic materials, although artificial aging negatively affected the material properties over time. Further investigations are recommended to assess long-term durability and optimize nanoparticle percentage for clinical applications.