MDPI Acta Medica Okayama 2227-9059 12 8 2024 Surface Pre-Reacted Glass-Ionomer Eluate Suppresses Osteoclastogenesis through Downregulation of the MAPK Signaling Pathway 1835 EN Janaki Chandra Department of Oral Science and Translational Research, College of Dental Medicine, Nova Southeastern University Shin Nakamura Department of Pathophysiology-Periodontal Science, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Satoru Shindo Department of Oral Science and Translational Research, College of Dental Medicine, Nova Southeastern University Elizabeth Leon Department of Oral Science and Translational Research, College of Dental Medicine, Nova Southeastern University Maria Castellon Department of Oral Science and Translational Research, College of Dental Medicine, Nova Southeastern University Maria Rita Pastore Department of Oral Science and Translational Research, College of Dental Medicine, Nova Southeastern University Alireza Heidari Department of Oral Science and Translational Research, College of Dental Medicine, Nova Southeastern University Lukasz Witek Biomaterials Division, NYU Dentistry Paulo G. Coelho Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami Toshiyuki Nakatsuka R&D Department, Shofu Inc. Toshihisa Kawai Department of Oral Science and Translational Research, College of Dental Medicine, Nova Southeastern University Surface pre-reacted glass-ionomer (S-PRG) is a new bioactive filler utilized for the restoration of decayed teeth by its ability to release six bioactive ions that prevent the adhesion of dental plaque to the tooth surface. Since ionic liquids are reported to facilitate transepithelial penetration, we reasoned that S-PRG applied to root caries could impact the osteoclasts (OCs) in the proximal alveolar bone. Therefore, this study aimed to investigate the effect of S-PRG eluate solution on RANKL-induced OC-genesis and mineral dissolution in vitro. Using RAW264.7 cells as OC precursor cells (OPCs), TRAP staining and pit formation assays were conducted to monitor OC-genesis and mineral dissolution, respectively, while OC-genesis-associated gene expression was measured using quantitative real-time PCR (qPCR). Expression of NFATc1, a master regulator of OC differentiation, and the phosphorylation of MAPK signaling molecules were measured using Western blotting. S-PRG eluate dilutions at 1/200 and 1/400 showed no cytotoxicity to RAW264.7 cells but did significantly suppress both OC-genesis and mineral dissolution. The same concentrations of S-PRG eluate downregulated the RANKL-mediated induction of OCSTAMP and CATK mRNAs, as well as the expression of NFATc1 protein and the phosphorylation of ERK, JNK, and p38. These results demonstrate that S-PRG eluate can downregulate RANKL-induced OC-genesis and mineral dissolution, suggesting that its application to root caries might prevent alveolar bone resorption. No potential conflict of interest relevant to this article was reported.