A Comparative Analysis of Graphene Versus Zirconia Fixed Dental Prostheses: An In Vitro Study

Objectives This study set out to compare the mechanical behavior of graphene and zirconia in the context of their potential use in fixed dental prostheses. Specifically, we evaluated three critical properties: Rockwell hardness, to understand surface durability; compressive strength, to assess resistance to biting forces; and flexural strength, to examine performance under bending stress. To approximate real-world conditions, all samples were subjected to thermocycling, simulating the thermal changes typical of the oral cavity. The goal was to explore whether graphene could serve as a viable alternative to zirconia in restorative applications. Methods A systematic in vitro protocol was followed. Standardized specimens of graphene and zirconia were fabricated and subjected to 30,000 thermocycles between 5°C and 55°C. Mechanical tests were conducted using a universal testing machine. Rockwell hardness was measured using a standard durometer, while compressive and flexural strengths were evaluated through load-to-failure testing. Data were statistically analyzed using independent-sample t-tests, with significance defined at p<0.05. Results Zirconia showed markedly higher compressive strength compared to graphene, making it better suited for high-load areas of the mouth. Interestingly, the two materials performed similarly in Rockwell hardness, suggesting comparable surface durability. Flexural strength results were also close, with no significant difference, indicating that graphene may perform well under bending or tensile forces. These outcomes reaffirm zirconia's status as a robust material for prosthodontics while also opening the door for graphene as a lightweight, structurally capable alternative. Conclusion While zirconia continues to outperform in terms of compressive strength, graphene demonstrates meaningful potential due to its comparable flexural strength and hardness, along with the added advantage of being significantly lighter. These findings support further investigation into graphene's role in restorative dentistry, especially in cases where weight, design complexity, or aesthetics demand alternative materials. Future research should explore its biocompatibility, long-term performance, and integration with current dental systems.