Cytotoxicity of hexagonal boron nitride incorporated conventional and resin modified glass ionomer cements: in vitro study.

backgroundIncorporation of nanomaterials into cement has been proposed to enhance their physical performance; however, potential biological effects require careful evaluation. This study aimed to investigate cytotoxic profile of hexagonal boron nitride(hBN)-incorporated conventional glass ionomer cements(GIC) and resin-modified glass ionomer cements(RMGIC) using mouse fibroblasts(L929) and human umbilical vein endothelial cells(HUVECs).

methodsGIC and RMGIC specimens were modified with hBN nanoparticles at concentrations of 0.5 wt%, 1 wt%, and 1.5 wt% and unmodified materials were also included. A total of 56 disc-shaped specimens (5 mm×2 mm) were prepared (n = 7 per group). Extracts collected after 1-day and 7-day incubation periods were applied to L929 and HUVEC cells at dilutions of 1:2, 1:5, and 1:10. Cell viability was assessed after 48 and 96-hours using MTT assay. Data were analyzed using two-way ANOVA followed by Tukey’s post hoc test (α = 0.05).

resultsCell viability was significantly affected by material type, extract concentration, cell line, and exposure duration, with extracts obtained after 7 days showing significantly higher cytotoxicity compared to 1-day extracts in both L929 and HUVEC cells. In HUVEC cells, 7-day extracts resulted in lower viability than 1-day extracts, particularly at the 1:2 dilution and 96-hour exposure, where viability decreased to approximately 49% in the RMGIC-2 group. Under the same conditions, GIC groups showed relatively higher viability than RMGIC groups, although still below control levels. In contrast, L929 fibroblasts maintained generally higher viability, with most 96-hour values remaining above 70%, even with 7-day extracts. Higher dilutions (1:5 and 1:10) improved viability in both cell lines, especially at 48 h. Overall, RMGIC materials tended to reduce viability more than GIC, particularly in HUVEC cells under concentrated and prolonged exposure, while hBN incorporation did not induce a consistent or dose dependent increase in cytotoxicity.

conclusionsThe cytotoxic response of hBN incorporated cements depended on cell type, concentration, and exposure time. Within the tested conditions, hBN did not cause a consistent increase in cytotoxicity in either GIC or RMGIC. Importantly, the lack of a significant increase in cytotoxicity following hBN incorporation indicates that these modified cements maintain their biocompatibility, supporting their potential biological compatibility for clinical use.