Dental pulp is a major component of the dental body that serves to maintain the tooth life and function. The aim of the present work was to develop a system that functions as a growth-permissive microenvironment for dental pulp regeneration using a decellularized dental pulp (DDP) matrix, 5-Aza-2′-deoxycytidine (5-Aza), and Extracellular Vesicles (EVs) derived from human Dental Pulp Stem Cells (hDPSCs). Human dental pulps extracted from healthy teeth, scheduled to be removed for orthodontic purpose, were decellularized and then recellularized with hDPSCs. The hDPSCs were seeded on DDP and maintained under different culture conditions: basal medium (CTRL), EVs, 5-Aza, and EVs+-5-Aza. Immunofluorescence staining and Western blot analyses were performed to evaluate the proteins’ expression related to dentinogenesis, such as ALP, RUNX2, COL1A1, Vinculin, DMP1, and DSPP. Protein contents found in the DDP recellularized with hDPSCs were highly expressed in samples co-treated with EVs and 5-Aza compared to other culture conditions. This study developed a DDP matrix loaded by hDPSCs in co-treatment with EVs, which might enhance the dentinogenic differentiation with a high potentiality for endodontic regeneration.

The gingival tissue can be collected in an easy way and represent an accessible source to isolate gingival-derived mesenchymal stem cells (GMSCs). GMSCs are a subpopulation of dental-derived mesenchymal stem cells that show the mesenchymal stem cells (MSCs) features, such as differentiation abilities and immunomodulatory properties. Dental-derived stem cells are also expandable in vitro with genomic stability and the possibility to maintain the stemness properties over a prolonged period of passages. Moreover, several preclinical studies have documented that the extracellular vesicles (EVs) released from GMSCs possess similar biological functions and therapeutic effects. The EVs may represent a promising tool in the cell-free regenerative therapy approach. The present review paper summarized the GMSCs, their multi-lineage differentiation capacities, immunomodulatory features, and the potential use in the treatment of several diseases in order to stimulate tissue regeneration. GMSCs should be considered a good stem cell source for potential applications in tissue engineering and regenerative dentistry.

In recent years, Zirconia-reinforced Lithium Silicate ceramic (ZLS), combining lithium-silicate and zirconia features, has shown to have excellent mechanical and aesthetic characteristics. Thus, the aim of this study was to compare the fracture strength of ZLS single crowns cemented with two different cementation techniques. Twenty crowns were realised and cemented on teeth replicas achieved from an extracted premolar human tooth. The samples were divided into two groups of 10 specimens each, Glass-ionomeric cement (GIC) group and Self-Adhesive Resin Cement (ARC) group. The mechanical test was performed using a universal testing machine. The specimens were then evaluated with a scanning electron microscope (SEM) to identify for all crowns and related abutments the pattern of fracture after the breaking point. The data obtained were statistically analysed. The mean fracture toughness values and standard deviations (±SD) were 2227 ± 382 N and 3712 ± 319 N respectively for GIC and ARC groups. In fact, t-test showed a statistically significant difference between the two groups (p < 0.001). Moreover, the SEM results demonstrated portions of abutments still attached to the crown fragments in the ARC group, whilst these were not present in the GIC group. Within the limitations of this study, these results suggest the use of adhesive cementation for ZLS crowns, which significantly increase the compressive strength of ZLS restorations compared to GIC.

Background. Inflammatory responses have been associated with delayed oral mucosal wound healing and the pathogenesis of the periodontal disease. The invasion of microbes into the tissues and the establishment of a chronic infection may be due to impaired healing. The protracted inflammatory phase may delay wound healing and probably support tissue fibrosis and reduce tissue regeneration. Vanillin is a well‐known natural compound with potential anti‐inflammatory capacity. Hence, we hypothesized that Vanillin could accelerate wound healing reducing inflammation and especially cytokine production making the oral tissue repair process easier. Methods. Our hypothesis was tested using primary human gingival fibroblast (HGF) cell pretreated with Vanillin and primed with IL‐1β, as inductor of proinflammatory environment. After 24 hours of treatments, the gene expression and production of IL‐6, TNF‐α, IL‐8, COX‐2, iNOS, and nitric oxide (NO) generation and the wound healing rate were determined. Results. In IL‐1β‐primed cells, preincubation with Vanillin reduced IL‐6, IL‐8, COX‐2, and iNOS expression and NO release, compared to IL‐1β‐primed cells. Moreover, Vanillin determines the increased gene expression of nAChRα7, leading us to hypothesize a role of Vanillin in the activation of the cholinergic anti‐inflammatory pathway. Furthermore, in presence of mechanical injury, the Vanillin preincubation, wound closure may be reducing the expression and release of IL‐6 and TNF‐α and upregulation of COX‐2 and IL‐8. Conclusion. Together, the results of this study highlight the anti‐inflammatory and tissue repair ability of Vanillin in IL‐1β‐primed HGF. Therefore, Vanillin shows a potential therapeutic interest as an inflammatory modulator molecule with novel application in periodontal regeneration and oral health.

Oliva S, et al. J Periodontal Implant Sci. 2022 Sep;52:e32. https://doi.org/10.5051/jpis.2201780089

The surface structure of the titanium dental implants can modulate the activity of mesenchymal stem cells in order to promote the upregulation of osteoblastic related genes and the release of extracellular matrix (ECM) components. The present work was focused on the in vitro evaluation of the interaction of human periodontal ligament stem cells (hPDLSCs) and two different implant titanium surfaces topography (CTRL and TEST). This study was aimed at analyzing the cytotoxicity of the dental implant surfaces, the cellular adhesion capacity, and the improvement in the release of ECM molecules in an in vitro model. These parameters were carried out by means of the microscopic evaluation, viability assays, immunofluorescence, Western blot and RT-PCR investigations. The knowledge of the cell/implant interaction is essential for implant healing in order to obtain a more performing surfaces that promote the ECM release and provide the starting point to initiate the osseointegration process.