Titanium dental implants are one of the modalities to replace missing teeth. The release of titanium particles from the implant’s surface may modulate the immune cells, resulting in implant failure. However, little is known about the immune microenvironment that plays a role in peri-implant inflammation as a consequence of titanium particles. In this study, the peri-implant gingival tissues were collected from patients with failed implants, successful implants and no implants, and then a whole transcriptome analysis was performed. The gene set enrichment analysis confirmed that macrophage M1/M2 polarization and lymphocyte proliferation were differentially expressed between the study groups. The functional clustering and pathway analysis of the differentially expressed genes between the failed implants and successful implants versus no implants revealed that the immune response pathways were the most common in both comparisons, implying the critical role of infiltrating immune cells in the peri-implant tissues. The H&E and IHC staining confirmed the presence of titanium particles and immune cells in the tissue samples, with an increase in the infiltration of lymphocytes and macrophages in the failed implant samples. The in vitro validation showed a significant increase in the level of IL-1β, IL-8 and IL-18 expression by macrophages. Our findings showed evidence that titanium particles modulate lymphocyte and macrophage polarization in peri-implant gingival tissues, which can help in the understanding of the imbalance in osteoblast–osteoclast activity and failure of dental implant osseointegration.

This study aimed to develop polycaprolactone (PCL) electrospun membranes coated with mineral trioxide aggregate/hydroxyapatite (MTA/HA) as a potential material for dental pulp capping. Initially, the PCL membrane was prepared by an electrospinning process, which was further surface coated with MTA (labeled as PCLMTA) and HA (labeled as PCLHA). The physico-chemical characterization of the fabricated membranes was carried out using field emission scanning electron microscopy (FE-SEM)/Energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman spectroscopy, and contact angle analysis. The biocompatibility of the human dental pulp stem cells (hDPSCs) on the fabricated membranes was checked by XTT assay, and the hDPSCs adhesion and spreading were assessed by FE-SEM and confocal microscopy. The wound healing ability of hDPSCs in response to different electrospun membrane extracts was examined by scratch assay. The surface morphology analysis of the membranes by FE-SEM demonstrated a uniform nanofibrous texture with an average fiber diameter of 594 ± 124 nm for PCL, 517 ± 159 nm for PCLHA, and 490 ± 162 nm for PCLMTA. The elemental analysis of the PCLHA membrane indicated the presence of calcium and phosphorous elements related to HA, whereas the PCLMTA membrane showed the presence of calcium and silicate, related to MTA. The presence of MTA and HA in the PCL membranes was also confirmed by Raman spectroscopy. The water contact analysis demonstrated the hydrophobic nature of the membranes. The results indicated that PCL, PCLHA, and PCLMTA membranes were biocompatible, while PCLMTA exhibited better cell adhesion, spreading, and migration.

Objective The interest in bioceramic materials has been steadily growing for different applications in endodontics. With the continued introduction of new bioceramic-based materials into the market, it is of great importance to assess the biocompatibility before providing recommendations on their clinical use. This study evaluated the in vitro cytotoxicity and mineralization potential of two consistencies of unset premixed bioceramic material (TotalFill BC RRM putty and TotalFill BC sealer) compared with an epoxy resin-based sealer (AH Plus) on osteoblast cells. Materials and Methods Overall, 100% extracts were obtained by weighing 0.1 g of each material in 1 mL of cell culture media. Primary human osteoblast (HOB) cells (n = 4) were treated with different concentrations (100, 50, 25, 12.50, and 6.25%) of each extract. XTT assay and Alizarin Red S staining were used to evaluate the cytotoxic effect and the biomineralization potential, respectively. Statistical Analysis Data were analyzed by one-way analysis of variance followed by Tukey's post hoc tests. Results The cytotoxicity assay after 24 h treatment showed that all materials at high concentrations of the extract (100 and 50%) were toxic to HOB (p < 0.001). On the contrary to TotalFill BC RRM Putty, AH Plus and TotalFill BC sealer were toxic at 25% concentration. However, at 12.5% concentration and lower, all materials were nontoxic. The mineralization potential analyzed after 7 and 14 days showed that TotalFill BC material–treated cells could deposit mineralized nodules in the normal and osteogenic medium unlike AH plus-treated cells. Conclusion At low concentrations, TotalFill BC materials showed higher biocompatibility to HOB cells than AH Plus, enhanced the viability of the cells, maintained their typical morphology, and induced the formation of mineralized nodules. Despite the encouraging data, clinical trials are needed to identify the effect of this material on the long-term outcome of endodontic treatment.

Objective: The objective of the present study is to isolate stem cells from inflamed dental pulp tissues (I-DPSCs) and study the characteristic such as surface markers, osteo/odontogenic differentiation potential between the outgrowth (OG) and enzymatic digestion (COL) methods. Materials and methods: I-DPSCs harvested by both methods were analysed for Mesenchymal Stem Cell marker expression by flow cytometry. The metabolic activity of the isolated cells was assessed by MTT assay. The Alkaline Phosphatase (ALP) and Alizarin red staining was done to analyse the osteogenic potential of isolated cells. The osteo/odontogenic differentiation was done by checking the expression of Dentine Matrix Protein 1 (DMP1), Dentine Sialophosphoprotein (DSPP), ALP and Bone Gamma-Carboxyglutamate Protein (BGLAP) by Real time PCR. Results: The isolated cells were positive for MSC markers such as CD-90, CD-105 and CD-73 and negative for CD-14, CD-45 and STRO-1. MTT assay indicated that the I-DPSCs from OG method showed higher metabolic activity than cells from COL. However, the osteo/odontogenic differentiation was in favour of cells isolated by COL method. Conclusion: Although the cell metabolic rate was more in OG, the osteo/odontogenic differentiation was higher in COL, suggesting that the isolation method and culture conditions do affect the differentiation capacity of isolated cells.