Suwanna Jitpukdeebodintra

Purpose: This study aimed to investigate the minimum inhibitory concentration (MIC) and biological properties of modified glass-ionomer cement (BIO-GIC) supplemented with chlorhexidine diacetate (CHX).Methods: The BIO-GIC was originally a combining formulation of conventional glass-ionomer cement, chitosan, albumin and tricalcium phosphate. CHX was incorporated at various concentrations of 1.25%, 2%, 2.5%, 5%, 7.5% and 10%. Antimicrobial activity against certain microorganisms related to cariogenesis Streptococcus mutans (S. mutans), Streptococcus sanguinis (S. sanguinis), and Enterococcus faecalis (E. faecalis), was evaluated by microdilution test. One effective concentration of CHX was mixed with Penaeus merguiensis-Translationally Controlled Tumor Protein (Pmer-TCTP) and further conducted by biological tests including cell viability and mineralization in dental pulp.Results: S. mutans were inhibited at 7.5% CHX-modified BIO-GIC, while S. sanguinis and E. faecalis showed no inhibition at any concentration. Cell viability significantly decreased with 7.5% CHX-modified BIO-GIC after 72 h. Dental pulp exposed to this group formed smaller and fewer calcium nodules but adding Pmer-TCTP reduced cell death and slightly enhanced mineralization.Conclusion: 7.5% CHX-modified BIO-GIC shows potential for inhibiting S. mutans and having potential cell viability and mineralization in dental pulp cells.

We previously reported that mechanical vibration‐induced proinflammatory cytokines, interleukin‐6 (IL‐6) and IL‐8, expression in human periodontal ligament (hPDL) cells, however, the underlying mechanism remained unclear. Mechanical stimuli are able to activate cellular responses by inducing the activation of several signaling pathways including cytoskeletal changes and inflammation. The actin cytoskeleton is a highly dynamic network and plays many important roles in intracellular events. Here, we aimed to investigate the involvement of a pivotal mediator of inflammatory responses, nuclear factor‐κB (NF‐κB), and actin polymerization in vibration‐induced upregulation of IL‐6 and IL‐8 expression in hPDL cells. hPDL cells were pretreated with the NF‐κB inhibitor BAY 11‐7082 or cytochalasin D, respectively, before exposure to vibration. IL‐6 and IL‐8 messenger RNA (mRNA) and protein expression were quantified by quantitative polymerase chain reaction and enzyme‐linked immunosorbent assays, respectively. Subcellular localization of the NF‐κB p65 subunit was visualized by immunofluorescent staining. We found an increase in NF‐κB nuclear translocation in vibrated cells compared with control cells. Pretreatment with BAY 11‐7082 significantly inhibited vibration‐induced IL‐6 and IL‐8 mRNA and protein expression in hPDL cells. Moreover, pretreatment with cytochalasin D inhibited NF‐κB nuclear translocation and attenuated upregulation of IL‐6 and IL‐8 mRNA and protein in vibrated cells. Therefore, modulation of actin cytoskeletal polymerization in response to vibration may activate the NF‐κB signaling pathway and subsequently upregulate IL‐6 and IL‐8 expression in hPDL cells.