Cytotoxic Effect of Niobium Phosphate Glass–based Gutta-Percha Points on Periodontal Ligament Fibroblasts In Vitro

The outcome of root canal obturation might be affected by the chemical components of the chosen filling materials. Niobium phosphate glass–based gutta-percha (GNB) was proposed as a biomaterial-based obturation point. This study aimed to investigate the cytotoxic and cell modulation effects of GNB points on human periodontal ligament fibroblasts (PDLFs) in vitro. Human PDLFs were cultured for the assays. Extracts of regular gutta-percha (GP) points and GNB were obtained, serially diluted (1:5, 1:10, and 1:25), and used to stimulate PDLFs. A cell viability assay was performed using alamarBlue reagent (Molecular Probes, Waltham, MA), and reverse transcription quantitative polymerase chain reaction was used to assess the gene expression for collagen type I and cementum protein 1. One-way analysis of variance followed by the Tukey post hoc test was performed (P < .05). Regular GP reduced cell viability only in pure extracts, whereas GNB exhibited cytotoxicity to PDLFs in pure extracts as well as 1/5 and 1/10 dilutions. The gene expression of collagen type I was down-regulated only in the GNB group (P < .05). The expression of cementum protein 1 remained unaltered by both tested materials. The addition of niobium phosphate glass to GP points increased cytotoxicity, affecting PDLF viability and partially disturbing physiological cell function.