Effects of adding functionalized graphene oxide nanosheets on physical, mechanical, and anti‑biofilm properties of acrylic resin: In vitro- experimental study

Polymethyl methacrylate resin is widely used in orthodontic treatments. Graphene oxide (GO) has reactive functional groups on its surface that facilitate binding to various materials such as polymers, biomolecules, DNA, and proteins. This study aimed to investigate the impact of adding functionalized GO nanosheets on the physical, mechanical, cytotoxicity, and anti‑biofilm properties of acrylic resin.

In this experimental study, fifty samples (for each test) were divided into groups of 10, in the form of acrylic resin discs with concentrations of 0, 0.25, 0.5, 1, and 2 weight percentage (wt%) of functionalized GO nanosheets and also the control group. Samples were evaluated in terms of physical properties (surface hardness, surface roughness, compressive strength, fracture toughness, and flexural strength), anti‑biofilm properties (On four groups of micro‑organisms, including Streptococcus mutans, Streptococcus sanguis, Staphylococcus aureus, and Candida albicans), and cytotoxicity. Data were analyzed using SPSS software version 22, descriptive statistics, one‑way analysis of variance test, and Tukey post hoc test. The significance level was considered P < 0.05.

No significant difference was observed between the different groups with weight percentages of 0.25, 0.5, 1, and 2% nano GO (nGO) and the control group (without nGO) in terms of surface roughness and toughness. However, compressive strength, three‑point flexural strength, and surface hardness showed significant differences between the groups. Furthermore, the degree of cytotoxicity increased by increasing the weight percentage of nano‑GO.

The addition of functionalized nGO in appropriate concentrations to polymethyl methacrylate can improve the anti‑bacterial and anti‑fungal biofilm properties without changing or increasing their physical and mechanical properties.