Antibiofilm and mechanical properties of silver nanowire-modified glass ionomer cement

Abstract

Background: Glass ionomer cement (GIC) is a commonly used restorative material in dentistry, but GIC does not have significant antibiofilm effects and its mechanical strength is limited.

Objective: To investigate the antibiofilm and mechanical properties of a newly developed silver nanowire (AgNW) modified GIC.

Methods: GICs were modified with different nanosilver formulations including 0.05%wt AgNW, 0.5%wt AgNW, 0.05%wt silver nanoparticle (AgNP) and 0.5%wt AgNP. Biofilms of Streptococcus mutans were cultured for 72 h on GIC specimens. Scanning electron microscopy (SEM) was conducted to observe the accumulation and morphology of Streptococcus mutans on the material surfaces. Another set of biofilm/specimens was treated with SYTO-9 and the biofilm development was evaluated by quantifying the visible stain with an inverted fluorescence microscope. The compressive strength of the specimens was assessed according to ISO 9917-1:2007. The colour of GICs was compared using the VITA Easyshade system.

Results: SEM images showed that fewer biofilms were accumulated on nanosilver-modified GICs. The Streptococcus mutans quantity was significantly lower in all nanosilver-modified groups compared to conventional GIC (p<0.0001). GIC modified with 0.5% AgNP showed slightly lower compressive strength than the negative control (58.3 ± 12.9 MPa vs 78.3 ± 13.8 MPa); but there is no significant difference between all study groups. The colour change between AgNW-modified GIC and conventional GIC was significantly lower than that between AgNP-modified GIC and conventional GIC.

Conclusion: AgNW-modified GIC showed superior antibiofilm effect and comparable compressive strength to conventional GIC. In addition, the complement of AgNW would not influence the colour stability of GIC as much as AgNP.

Clinical significance: This study developed a novel AgNW-modified GIC material. It showed good antibiofilm and mechanical properties and would not influence the colour stability of GIC. The AgNW-modified GIC has a large potential for clinical use and biomedical application.

Keywords: Antibiofilm; Dental caries; Dental materials; Glass ionomer cement; Silver nanoparticle; Silver nanowire.