A novel surgical technique to resolve mucosal fenestration of a root apex: Apical tunnel surgery: A case report.

RATIONALE: Endodontic surgery, which includes apex resection, retro-fill and some regeneration procedures, is a traditional way to deal with apex fenestration. The endodontic surgery could bring large flap, curtate root length, non-healing mucosa and soft tissue deficiency in the apex area. Other treatment options might be considered according to different etiological factors. Mucogingival surgery provides some ideas in accumulation of soft and hard tissues, especially some unique methods such as "tunnel technique" bringing us a view of minimal invasive surgery approach. A novel surgery named "apical tunnel surgery" was reported here to resolve a root apex exposure with the tunnel-like technique. PATIENT CONCERNS: A young female complained about root exposure of upper right anterior tooth without history of trauma or orthodontic treatment. DIAGNOSIS: The intraoral examination revealed a buccal root apex exposure about 3mm in diameter of #12 (FDI teeth numbering system). The tooth was slightly dark with Class 1 mobility. The periodontal situation was good and the occlusion check revealed no traumatic bite on #12. The cone-beam computed tomography (CBCT) showed a bone fenestration from the buccally lower 1/2 root surface to the apex and bone absorption around the apex. It also revealed a bone contour deficiency in #12 area. INTERVENTIONS: Root canal treatment, root surface debridement, and soft tissue combined with hard tissue accumulation were carried out in one tunnel-like surgery. OUTCOMES: Examination of 12-month follow-up showed a healed and thickened mucosa in the buccally apical region and CBCT showed the continuous lamina dura occupied the buccal aspect of #12 root apex. LESSONS: This new apical tunnel surgery provided soft and hard tissue accumulation in one minimal invasive way in the apex exposure case caused by bone fenestration and thin mucosa.

Polypeptides IGF-1C and P24 synergistically promote osteogenic differentiation of bone marrow mesenchymal stem cells in vitro through the p38 and JNK signaling pathways.

OBJECTIVES: Insulin-like growth factor-1 (IGF-1) and bone morphogenetic protein 2 (BMP-2) both promote osteogenesis of bone marrow mesenchymal stem cells (BMSCs). IGF-1C, the C domain peptide of IGF-1, and P24, a BMP-2-derived peptide, both have similar biological activities as their parent growth factors. This study aimed to investigate the effects and mechanisms of polypeptides IGF-1C and P24 on the osteogenic differentiation of BMSCs. METHODS: The optimum concentrations of IGF-IC and P24 were explored. The effects of the two polypeptides on BMSC proliferation and osteogenic differentiation were examined using a CCK-8 assay, flow cytometry, alkaline phosphatase (ALP) staining, ALP activity assay, alizarin red S staining, qPCR, and Western blotting. In addition, specific pathway inhibitors were utilized to explore whether the p38 and JNK pathways were involved in this process. RESULTS: The optimal concentration of both polypeptides was 50 µg/ml. IGF-1C and P24 synergistically promoted BMSC proliferation, increased ALP activity and calcified nodule formation, upregulated the mRNA and protein levels of Osx, Runx2, Ocn, Opn, and Col1a1, and improved the phosphorylation levels of p38 and JNK proteins. Inhibition of the pathways significantly reduced p38 and JNK activation and blocked Runx2 expression while inhibiting ALP activity and calcified nodule formation. CONCLUSIONS: These findings suggest that IGF-1C and P24 synergistically promote the osteogenesis of BMSCs through activation of the p38 and JNK signaling pathways.

Biocompatibility and Angiogenic Effect of Chitosan/Graphene Oxide Hydrogel Scaffolds on EPCs.

Angiogenesis in the field of tissue engineering has attracted significant attention. Graphene oxide has become a promising nanomaterial in tissue engineering for its unique biochemical properties. Therefore, herein, a series of chitosan (CS)/graphene oxide (GO) hydrogel scaffolds were synthesized by crosslinking CS and GO at different concentrations (0.1, 0.5, and 1.0 wt.%) using genipin. Compared with the CS hydrogel scaffolds, the CS/GO hydrogel scaffolds have a better network structure and mechanical strength. Then, we used endothelial progenitor cells (EPCs) extracted from human umbilical cord blood and cocultured these EPCs with the as-prepared scaffolds. The scaffolds with 0.1 and 0.5 wt.%GO showed no considerable cytotoxicity, could promote the proliferation of EPCs and tube formation, and upregulated the expressions of CD34, VEGF, MMP9, and SDF-1 in EPCs compared to the case of the scaffold with 1.0 wt.%GO. This study shows that the addition of graphene oxide improves the structure of chitosan hydrogel and enhances the proliferation activity and angiogenic capacity of EPCs.