Mineral trioxide aggregate repair of lateral root perforation using intentiional replantation and bone grafting

Root perforation is a significant complication during root canal treatment. Root perforation can result in loss of integrity of the root structure and severe periodontal and bone defect. Repair of lateral root perforation presents a clinical challenge to the operator. This report is of root perforation during post space preparation in a right maxillary central incisor that has caused an extensive periodontal lesion. Since the bone lesion was large and unreachable from either a coronal access cavity or buccal surgical flap, a combination of mineral trioxide aggregate sealing, bone grafting, and intentional replantation was used as the method of treatment. The patient’s symptoms ceased and the existing lesions resolved during the 5-year follow-up.published_or_final_versio

The interplay of dental pulp stem cells and endothelial cells in an injectable peptide hydrogel on angiogenesis and pulp regeneration in vivo

Securing an adequate blood supply for the survival of cell transplants is critical for a successful outcome in tissue engineering. Interactions between endothelial and progenitor/stem cells are important for vascularization of regenerating tissue. Recently, self-assembling peptide nanofibers were described as a promising environment for pulp regeneration due to their synthetic nature and controlled physicochemical properties. In this study, the peptide hydrogel PuraMatrix™ was used as a scaffold system to investigate the role of dental pulp stem cells (DPSCs) in triggering angiogenesis and the potential for regenerating vascularized pulp in vivo. Human umbilical vein endothelial cells (HUVECs), DPSCs, or cocultures of both cell types were encapsulated in three-dimensional PuraMatrix. The peptide nanofiber microenvironment supported cell survival, cell migration, and capillary network formation in the absence of exogenous growth factors. DPSCs increased early vascular network formation by facilitating the migration of HUVECs and by increasing vascular endothelial growth factor (VEGF) expression. Both the DPSC-monoculture and coculture groups exhibited vascularized pulp-like tissue with patches of osteodentin after transplantation in mice. The cocultured groups exhibited more extracellular matrix, vascularization, and mineralization than the DPSC-monocultures in vivo. The DPSCs play a critical role in initial angiogenesis, whereas coordinated efforts by the HUVECs and DPSCs are required to achieve a balance between extracellular matrix deposition and mineralization. The findings of this study also highlighted the importance of a microenvironment that supports cell-cell interactions and cell migration, which contribute to successful dental pulp regeneration.published_or_final_versio

TGF-β1-induced differentiation of SHED into functional smooth muscle cells

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Coculture of stem cells from apical papilla and human umbilical vein endothelial cell under hypoxia increases the formation of three-dimensional vessel-like structures in vitro

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Hard Tissue Engineering

Peer reviewe

Tissue Engineering in Oral and Maxillofacial Surgery : From Lab to Clinics

Regenerative medicine aims at the functional restoration of tissue malfunction, damage or loss, and can be divided into three main approaches. Firstly, the cell-based therapies, where cells are administered to re-establish a tissue either directly or through paracrine functions. Secondly, the often referred to as classical tissue engineering, consisting of the combined use of cells and a bio-degradable scaffold to form tissue. Thirdly, there are material-based approaches, which have made significant advances which rely on biodegradable materials, often functionalized with cellular functions (De Jong et al. 2014). In 1993, Langer and Vacanti, determined tissue engineering as an “interdisciplinary field that applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function”. They published this definition in Science in 1993. Tissue engineering has been classically thought to consist of three elements: supporting scaffold, cells and regulating factors such as growth factors (Fig. 1). Depending on the tissue to be regenerated, all three vary. Currently, it is known, that many other factors may have an effect on the outcome of the regenerate. These include factors enabling angiogenesis, physical stimulation, culture media, gene delivery and methods to deliver patient specific implants (PSI) (Fig. 2). During the past two decades, major obstacles have been tackled and tissue engineering is currently being used clinically in some applications while in others it is just taking its first baby steps.Peer reviewe

Endothelial differentiation of dental stem cells in a three-dimensional microtissue culture system

Organizers: International Society for Stem Cell Research (ISSCR), StemBANCC and the Basel Stem Cell NetworkPoster presentation: no. P132Dental stem cells have been demonstrated to have potential to differentiate into several lineages, including endothelial cells. However, the efficiency of in-vitro endothelial differentiation of dental pulp stem cells (DPSCs) and stem cells from exfoliated human deciduous teeth (SHED) is questionable. The present study aimed to investigate the endothelial differentiation potential of DPSCs and SHED in a three-dimensional microtissue spheroid system. Threedimensional (3D) microtissue-spheroids of DPSCs and SHED were fabricated using 12-series micro-molds (MicroTissues Inc.). DPSCs and SHED cultured on two-dimensional (2D) sixwell culture plates were used as the control groups. Twentyfour hours after DPSCs and SHED were seeded in plates (2D) or micro-molds (3D), the culture medium was changed to fully supplemented endothelial growth medium -2 (Lonza Biologics Inc.) After 3-, 6-, and 9- days of induction, 3D microtissues were transferred onto the adherent culture surfaces and allowed to dissociate into cells, while 2D cultures were trypsinized and sub-cultured. Then, the cells were analyzed for expression of endothelial markers – eNOS, vWF, CD31, VE-cadherin, VEGFR-1 and 2 via immunofluorescence and qPCR. Matrigel assay was performed to assess the cells’ ability to form capillary-like tube structures in-vitro. Immunofluorescence and qPCR results indicated an enhanced endothelial differentiation of 3D microtissue derived cells compared with 2D induced cells in relation to both DPSCs and SHED. SHED dissociated from induced microtissues were positive for endothelial markers and were able to form endothelial-like tube structures on matrigel. In contrast, 2D induced SHED failed to form such structures on Matrigel. However, DPSCs induced in either 3D or 2D could not form endothelial-like tube structures on matrigel. Threedimensional microtissue is a promising culture system for promoting endothelial differentiation efficiency of dental stem cells in-vitro. SHED hold a higher potential for endothelial differentiation compared to that of DPSCs. Funding Source Small Project Funding, HKU. (Project code: 20140917617

The role of vasculature engineering in dental pulp regeneration

First joint symposium between the Dental Hospital Center for Global Oral Health at the Osaka University and Faculty of Dentistry, the University of Hong Kong