The impact of nanosized graphene oxide on the rheological, physical, mechanical, and antibacterial properties of condensation silicone dental impression materials.

Background: Condensation silicone dental impression materials are widely used but are limited by polymerization shrinkage, poor wettability, and susceptibility to bacterial contamination. This study evaluates the incorporation of nanosized graphene oxide (GO) as a multifunctional additive to address these issues.

Methods: GO was incorporated into a self-formulated silicone matrix at concentrations from 0 to 0.5 vol%. The resulting composites were comprehensively characterized for their physical, mechanical, rheological, and antibacterial properties.

Results: The incorporation of GO yielded significant, concentration-dependent improvements. Dimensional stability was markedly enhanced, with as little as 0.05% GO reducing 12-hour shrinkage from over 2% to just 0.06%. Handling characteristics were improved, with prolonged working times and enhanced flowability. Mechanical properties were also significantly affected, enabling targeted modification of hardness and flexibility; 0.1% GO increased Shore A hardness by over 14%, while 0.3% GO increased elongation at break by over 55%, demonstrating the ability to optimize the material for either rigidity or flexibility. Surface wettability was improved, with the contact angle decreasing by nearly 19%. Crucially, the composites demonstrated potent antibacterial activity, with 0.2% GO achieving up to 40% efficacy against S. mutans.

Conclusion: GO is a highly effective multifunctional additive that simultaneously addresses the key limitations of condensation silicones by enhancing dimensional accuracy, tailoring mechanical properties, improving handling, and increasing hygienic safety. These findings highlight the potential for developing a new class of advanced, high-performance dental impression materials.