Changes in matrix extracellular phosphoglycoprotein expression before and during in vitro osteogenic differentiation of human dental papilla mesenchymal cells.

The purpose of this study is to characterise the expression of matrix extracellular phosphoglycoprotein (MEPE) in cultured mesenchymal cells isolated from human dental papilla (PaMCs) of impacted third molars either before or during differentiation of these cells into osteo/odontoblasts. PaMCs, like mesenchymal cells deriving from human dental pulp (DPMCs), resulted positive for a number of mesenchymal markers including CD146 and STRO-1. During the first week in culture they showed a faster proliferation rate than DPMCs, coupled to an earlier down-regulation of MEPE. Also when the cells were further cultured in osteogenic medium (containing β-glycerophosphate, ascorbic acid and dexamethasone) for 40 days, MEPE down-regulation coupled to an increased expression of osteogenic markers, such as osteocalcin and alkaline phosphatase, occurred earlier in PaMCs than in DPMCs. Thus, our data, indicating that also in PaMCs MEPE expression is higher when cells proliferate, whereas it is downregulated as cells differentiated, are in favour of a role of MEPE as an early regulator of odontogenic differentiation. We also confirm the superior proliferative potential of PaMCs in comparison with DPMCs, coupled to a more rapid induction of osteogenic differentiation. Therefore, these cells represent an optimal source to be conveniently used for dental tissue engineering and tooth regeneration

Zoledronate treatment at subtoxic doses delays human primary osteoblasts differentiation

Zoledronic acid (ZA) belongs to the family of bisphosphonates (BPs), largely used in the clinical practice for the treatment of bone diseases, often associated with jaw osteonecrosis onset. Their pharmacological action consists in the block of the osteoclast- mediated bone resorption along with indirect action on osteoblasts (2). The aim of this study was to check the effect of ZA at subtoxic dose on primary human osteoblasts (HOs) in terms of cell viability, apoptosis occurrence, and differentiation induction. HOs were treated choosing the limit concentration (10(-5) M) which does not induce toxic effects. Live/dead staining, flow cytometry to evaluate apoptotic markers, mitochondrial membrane potential assay, osteocalcin western blotting, gp38 RTPCR, and collagen type I, PGE2, IL-6 ELISA tests were performed. The viability level between control and ZA-treated samples appears to be similar and no significant increase of apoptotic and necrotic cells in ZA-treated sample are evident. Bax expression and mitochondrial membrane potential were evaluated to establish if an early apoptotic pathway was triggered disclosing a higher protein expression in control sample and a good integrity of mitochondrial membrane in both experimental points. Type I collagen secretion and alkaline phosphatase activity are increased in ZA-treated sample, osteocalcin expression level is reduced in ZA-treated cells, whereas no modifications of gp38 mRNA level are evidenced. IL-6 secretion is lower in ZA-treated HOs with respect to control ones whereas no statistical differences are identified in PGE2 secretion level. These results highlight that ZA treatment at subtoxic dose is able to delay the osteoblastic differentiation process versus the osteocytic lineage, strengthening the pharmacological activity of the drug. Thus, the knowledge of ZA effects on osteoblasts allows to improve therapeutic protocols in order to strengthen drug pharmacological activity through a combined action on both osteoclasts and osteoblasts

Implant-Supported PMMA Monolithic Full-Arch Rehabilitation with Surgical Computer-Planned Guide and Immediate Provisional: A Case Report with One Year Follow-Up

The aim of this case report is to describe the surgical and prosthetic procedures to achieve maxillary and mandibular implant-supported PMMA monolithic full-arch rehabilitation (PMFR) with surgical computer-planned guide and immediate provisional. In such cases, the correct planning of dental implants’ position, length, and diameter and the prosthetic phases via computer-aided design are very important to achieve good aesthetic and functional long-lasting results

Characterizing scientific production of Italian Oral Surgery professionals through evaluation of bibliometric indices

The aim of this study was to characterize the scientific production of Italian Oral Surgery professionals by evaluating different bibliometric indices. The bibliometric evaluation was conducted on the Scopus Database upon all the Active Members joining three important Italian scientific societies in Oral Surgery (SIdCO, SIO, and SICOI). The scientific production was analysed by considering the number of total publications, number of total citations, h-index, and hc-index. Moreover, the overall sample was divided into two groups (Academics and Not Academics), according to the fact the professionals had or not a university position, and then into sub-groups according to the different career lengths. Statistical analyses were performed to compare the scientific Productivity amongst groups. For all the considered parameters a lack of homogeneity between groups was reported, and significantly greater mean values were recorded for the Academics compared to the Not Academics Group. Moreover, the h-index values increased more regularly as the career length progressed than the hc-index values, even if the last seemed to be less variable. h- and hc-indices are both stable bibliometric parameters, but as the hc-index values are related not only to the number of citation but also to their age, it seems to be less influenced by the authors’ career length. Bibliometric analysis of the scientific production in dentistry may facilitate the recognition of factors that may further enhance research activity and clinical performance and be useful for a comparative assessment of authors or research groups in terms of quality and quantity of the scientific production

RANK/RANKL/OPG signaling pathways in necrotic jaw bone from bisphosphonate-treated subjects

Osteonecrosis of the jaw (ONJ) is a chronic complication affecting long-term bisphosphonate-treated subjects, recognized by non-healing exposed bone in the maxillofacial region. The pathophysiological mechanism underlying ONJ has not been fully elucidated. The aim of the present study was to investigate the role of RANK/RANKL/OPG signaling pathway and, in parallel, to evaluate angiogenic and matrix mineralization processes in jaw bone necrotic samples obtained from bisphosphonate-treated subjects with established ONJ. Necrotic bone samples and native bone samples were processed for Light and Field Emission in Lens Scanning Electron Microscope (FEISEM) analyses, for Real-Time RT-PCR to evaluate the gene expression of TNFRSF11A (RANK), TNFSF11 (RANKL), and TNFSF11B (OPG) and for immunohistochemical analyses of VEGF and BSP expression. Morphological analyses performed by Light microscope and FEISEM show empty osteocytic lacunae and alteration of lamellar organization with degradation of the mineralized bone matrix in necrotic bone samples. A significant increase in TNFRSF11A, TNFSF11, TRAF6 and NFAT2 gene expression, and a reduction of TNFSF11B gene transcription level compared is also showed in necrotic bone compared to control samples. No significant difference of VEGF expression is evidenced, while lower BSP expression in necrotic bone compared to healthy samples is found. Even if the pathogenesis of bisphosphonate-associated ONJ remains unknown, a link between oral pathogens and its development seems to exist. We suppose lipopolysaccharide produced by bacteria colonizing and infecting necrotic bone and the surrounding viable area could trigger RANK/RANKL/OPG signaling pathway and, in this context, osteoclasts activation could be considered as a protective strategy carried out by the host bone tissue to delimitate the necrotic area and to counteract infection

Aesthetic Surgical Crown Lengthening Procedure

The aim of this case report was to describe the surgical sequence of crown lengthening to apically reposition the dentogingival complex, in addition to an esthetic restorative procedure. Many different causes can be responsible for short clinical crown. In these cases, the correct execution of a restorative or prosthetic rehabilitation requires an increasing of the crown length. According to the 2003 American Academy of Periodontology (Practice Profile Survey), crown lengthening is the most habitual surgical periodontal treatment

Proliferation and adhesion capability of human gingival fibroblasts onto zirconia, lithium disilicate and feldspathic veneering ceramic in vitro

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Changes in Matrix Extracellular Phosphoglycoprotein Expression before and during in Vitro

The purpose of this study is to characterise the expression of matrix extracellular phosphoglycoprotein (MEPE) in cultured mesenchymal cells isolated from human dental papilla (PaMCs) of impacted third molars either before or during differentiation of these cells into osteo/odontoblasts. PaMCs, like mesenchymal cells deriving from human dental pulp (DPMCs), resulted positive for a number of mesenchymal markers including CD146 and STRO-1. During the first week in culture they showed a faster proliferation rate than DPMCs, coupled to an earlier down-regulation of MEPE. Also when the cells were further cultured in osteogenic medium (containing β-glycerophosphate, ascorbic acid and dexamethasone) for 40 days, MEPE down-regulation coupled to an increased expression of osteogenic markers, such as osteocalcin and alkaline phosphatase, occurred earlier in PaMCs than in DPMCs. Thus, our data, indicating that also in PaMCs MEPE expression is higher when cells proliferate, whereas it is downregulated as cells differentiated, are in favour of a role of MEPE as an early regulator of odontogenic differentiation. We also confirm the superior proliferative potential of PaMCs in comparison with DPMCs, coupled to a more rapid induction of osteogenic differentiation. Therefore, these cells represent an optimal source to be conveniently used for dental tissue engineering and tooth regeneration

Transforming Growth Factor Beta 1 and Vascular Endothelial Growth Factor Levels in the Pathogenesis of Periodontal Disease

Periodontal disease is characterized by inflammation and bone loss. The balance between inflammatory mediators and their counter-regulatory molecules may be fundamental for determining the outcome of immune pathology of periodontal disease. Cytokines play crucial roles in the maintenance of tissue homeostasis, a process which requires a delicate balance between anabolic and catabolic activities. In particular, two families of growth factors-such as transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF) are thought to play important roles in modulating the proliferation and/or migration of structural cells involved in inflammation and regulation of immune responses. The aim of this work was to analyze gingival samples and periodontal tissue specimens collected from thirty-eight patients with chronic periodontal disease and from forty healthy individuals, in order to detect the expression and distribution of TGF-β1 and VEGF between the two groups. TGF-β1 and VEGF expression levels were detected using immunohistochemical analysis and computer-assisted morphometric analysis. The findings presented here suggest that biomarker such as TGF-β1 and VEGF have an important regulating role in the orchestration of the immune response, which in turn influence the outcome of disease establishment and evolution