Compressive Strength, Flexural Strength, Surface Microhardness, Wettability, and Bacterial Inhibition of Acrylic Bone Cements Modified with Silver-Doped CNTs

Background: Acrylic bone cement is widely used in orthopedics and dentistry for primary bone fixation. However, its limited mechanical strength and poor biological interface pose clinical challenges. To enhance their properties, carbon nanotubes (CNTs) and silver nanoparticles (Ag) have been explored. CNTs are known to reinforce polymers, while Ag nanoparticles provide antimicrobial benefits. Combining both may yield a synergistic effect, improving mechanical strength and antibacterial performance. Objective: This study evaluates the effect of incorporating 0.05 wt% silver-doped carbon nanotubes (Ag-doped CNTs) into acrylic bone cement. Key properties assessed include compressive strength, flexural strength, surface microhardness, wettability, and antibacterial activity against Staphylococcus aureus. Methods: A control group was prepared using traditional acrylic powder mixed with monomer liquid. In the modified group, 0.05 wt% Ag-doped CNTs were added to the acrylic powder before mixing. Compressive strength, flexural strength, surface microhardness, and wettability were tested. Antibacterial activity was evaluated using an agar diffusion test against S. aureus to test the inhibition zone. Independent sample t-tests (p < 0.05) were used to compare results between groups. Results: The modified acrylic cement exhibited significantly higher compressive strength (91 MPa), flexural strength (73 MPa), surface microhardness (39.1 VHN), and improved wettability (contact angle: 92.2°) compared to the control group, which recorded values of 72.3 MPa, 54.3 MPa, 21.1 VHN, and 107.9°, respectively. Additionally, the modified cement demonstrated a larger inhibition zone diameter against S. aureus (12.6 mm) than the control (9.1 mm) (P < 0.05). Conclusion: Incorporating 0.05 wt% Ag-doped CNTs into acrylic bone cement significantly improves its mechanical and antibacterial properties. This modification holds strong potential for clinical applications in both orthopedics and dentistry, offering enhanced strength, better surface characteristics, and effective bacterial inhibition compared to traditional formulations.