The Bio-C Sealer is a recently developed high-plasticity, calcium-silicate-based, ready-to-use material. In the present study, chemical elements of the materials were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The biocompatibility of the Bio-C Sealer was investigated using cytotoxicity tests and histological responses in the roots of dogs’ teeth. XRD, SEM, and FTIR produced hydrated calcium silicate in the presence of water molecules. In addition, FTIR showed the formation of calcium hydroxide and polyethylene glycol, a dispersing agent. The 1:4 dilutions of Bio-C Sealer presented weaker cytotoxicity than the Calcipex II in an in vitro system using the V-79 cell line. After 90 d, the periradicular tissue response of beagle dog roots was histologically evaluated. Absence of periradicular inflammation was reported in 17 of the 18 roots assessed with the Bio-C Sealer, whereas mature vertical periodontal ligament fibers were observed in the apical root ends filled with the Bio-C Sealer. Based on these results and previous investigations, the Bio-C Sealer is recommended as an effective root-end filling material. These results are relevant for clinicians considering the use of Bio-C Sealer for treating their patients.

Enamel matrix derivative (EMD) is applied for periodontal therapy. We created a synthetic amelogenin peptide (SP) derived from EMD, and have previously investigated the biological function of SP. However, it is unknown whether SP affects odontoblastic differentiation. In this study, we tested the effects of SP in the odontoblast-like cells, KN-3 cells. KN-3 cells were cultured with SP (0 to 1000 ng/mL) and then cultured for 3, 8, 24, or 48 h in order to determine the effects of SP on cell proliferation and detect its optimum concentration. KN-3 cells were treated with SP in odontogenic differentiation medium cultured for 3 or 7 days. Odontogenic markers were measured by the detection of alkaline phosphatase (ALP) activity and dentin sialo phosphoprotein (DSPP) expression, the calcified nodule formation, and calcium deposition. The addition of SP significantly promoted cell proliferation at 100 ng/mL, generating the greatest change in cell proliferation. SP also showed increased odontogenic expression markers and mineralization. These results suggest that SP, derived from EMD, could have potential for application in dental pulp capping.

Oral squamous cell carcinoma (OSCC) is a common malignancy in the oral cavity. Photodynamic therapy (PDT) is a new alternative for the treatment of diseases using photosensitizers (PS) and light. In this study, we used a photosensitizer complex (Ce6-MnNPs—Chlorin e6 combined with up-conversion nanoparticles NaYF₄:Yb/Er/Mn) to investigate the therapeutic effectiveness of this treatment against oral cancer cells. We also investigated the mechanism of action of near-infrared light PDT (NIR-PDT) combined with the Ce6-MnNPs. After determining a suitable concentration of Ce6-MnNPs using an MTT assay, human oral squamous cell carcinoma cells (HSC-3) were treated with NIR-PDT with Ce6-MnNPs. We examined the characteristics of Ce6-MnNPs by transmission electron microscopy (TEM); a zeta potential and particle size analyzer; Fourier-transform infrared spectroscopy (FTIR); cell viability by MTT assay; and apoptosis by FITC-Annexin V/PI assay. The mitochondrial membrane potential (MMP), apoptosis-related mRNA level (Bax and Bcl-2) and p53 protein were also researched. NIR-PDT with 0.5 ng/µL Ce6-MnNPs inhibited the proliferation of HSC-3 (p < 0.05). After treatment with NIR-PDT, changes in the mitochondrial membrane potential and apoptosis occurred (p < 0.01). The ratio of Bax/Bcl-2 and p53-positive cells increased (p < 0.01). These results suggest that this treatment can induce apoptosis of oral cancer cells.

Enamel matrix derivative (EMD) is used for periodontal tissue regeneration therapy, and can induce mineralization in dental pulp cells (DPCs). We designed a synthetic peptide (SP) derived from the response of cells to EMD, and investigated the effect of the SP on potentiating osteogenesis in DPCs, which have a critical role of dental pulp homeostasis. DPCs were treated with 0, 10, 100, or 1000 ng/mL SP to determine its effect on cell proliferation, cell migration, cell differentiation, and mineralization. We then examined the molecular effects of the SP, focusing on changes in the mitogen-activated protein kinases (MAPK) signaling pathway in these cells. The SP significantly promoted DPC proliferation and migration. Cultures treated with the SP also showed an enhanced expression of markers of osteogenic differentiation and mineralization. The SP also induced the activation of MAPK signaling pathway components. These results suggest that our SP could promote the dental pulp tissue repair by hard tissue formation and the mineralization through activating MAPK signaling pathway. This study provides the first evidence that SP might be a new material for dental pulp tissue treatment.