Ultrastructural and immunobiological responses of human periodontal ligament stem cells to novel tricalcium silicate sealers

Abstract

Objectives This study was conducted to examine the biocompatibility, regenerative potential, and immunomodulatory effects of three formulated calcium silicate-containing sealers (CSCS)-TotalFill BC Sealer (TFbc), NeoSEALER Flo (NS Flo), and NeoSEALER EZ Flo (NS EZ Flo)-on human periodontal ligament stem cells (hPDLSCs). Materials and Methods Third molars extracted from healthy patients (n = 15) were used to isolate hPDLSCs. Dilutions of 1:1, 1:2, and 1:4 were prepared, along with set sample discs of TFbc, NS Flo, and NS EZ Flo. The following assays were conducted: cell phenotyping, metabolic activity assessment (MTT assay), evaluation of cell attachment and morphology (scanning electron microscopy, SEM), cell migration analysis (wound-healing assay), cytoskeletal organization (phalloidin staining), proinflammatory cytokine release (IL-6 and IL-8, via ELISA), expression of differentiation markers (RT-qPCR), and assessment of cellular mineralization (Alizarin Red S staining). Statistical significance was set at p < 0.05. Results The metabolic activity assay demonstrated that cell viability increased over time with the use of bioceramic sealers.These sealers also promoted remarkable cell confluence and a higher number of focal adhesion complexes, as evidenced by the phalloidin assay. Furthermore, they demonstrated enhanced cell adhesion and anti-inflammatory effects compared to the negative control group (untreated cells), with the latter effect being more pronounced in the case of TotalFill BC Sealer. NS Flo, followed by NS EZ Flo, were the bioceramic sealers that most significantly promoted mineralized nodule formation, comparable to the positive control (Osteodiff), thus contributing to osteogenic and cementogenic differentiation<bold>.</bold> Conclusion This study demonstrates that all the bioceramic sealers investigated exhibit adequate cytocompatibility. NS Flo and NS EZ Flo demonstrate a strong ability to induce differentiation of hPDLSCs into osteogenic and cementogenic phenotypes. NS Flo significantly supports extracellular matrix mineralization. However, TFbc had a less substantial impact on these processes than the sealers. The effect was comparable during the first three days but decreased thereafter. In addition, the calcium silicate-containing sealers investigated exhibited relevant anti-inflammatory effects, offering potential therapeutic benefits in the field of regenerative endodontics.