Vascular Endothelial Growth Factor and E-Nitric Oxide Synthase-Mediated Regenerative Response Occurring upon Autologous and Heterologous Bone Grafts

Abstract

Bone regeneration procedures allow oral rehabilitation with dental implants also in edentulous ridges with severe bone atrophy. The integration of grafted materials with the host tissue can initiate regenerative, inflammatory and apoptotic response. Since molecular mechanisms exist at the basis of such response, the aim of this work is to investigate, by immunohistochemical analyses, the expression of proteins involved in the graft integration process, in parallel to clinical and histological modifications, occurring on sites treated with extraoral autologous bone graft deriving from the parietal region of the calvaria (eAB), intraoral autologous bone graft deriving from mandibular ramus (iAB) and heterologous bone graft from swine (hB) in human patients. In our study, the immunohistochemical expression of BSP, VEGF, eNOS in eAB samples was significantly higher (p< 0.05) compared to values recorded in iAB and hB samples. The inflammatory response, investigated by iNOS expression, was found lower in all autologous samples (eAB and iAB) compared to hB, at statistically significant values. Moreover, the expression of the pro-apoptotic molecule, Bax, resulted significantly lower (p< 0.05) in eAB than in iAB and hB samples. These values, together with the low number of apoptotic cells detected in autologous samples, suggest a good regenerative response when extraoral autologous bone graft is used in comparison to the response from the other grafts, and also suggest the use of calvaria graft as a predictable therapeutic procedure for repairing severe bone defects in oral and maxillofacial surgery, not only by clinical and biomechanical criteria, but also from a biomolecular aspect.After dental extractions, alveolar bone undergoes remodeling phenomena, leading to both vertical and horizontal bone loss (l). In addition to these phenomena, and to the generally poor quality of the bone in the upper distal regions, maxillary sinus pneumatization process occurs, determining an insufficient residual bone height to ensure primary stability of the implant placement (2). Novel classification of residual bone in the posterior maxilla considers, besides the width and the height of the residual alveolus, also the intermaxillary relationship (3). To correct these severe bone defects and to have a good prosthetic result, the use of onlay bone grafts, in addition to sinus floor lift, represents

Maxillary sinus augmentation procedures through equine-derived biomaterial or calvaria autologous bone: immunohistochemical evaluation of OPG/RANKL in humans

“…Several bone grafting materials were proposed for bone regeneration, such as autogenous, allogenic and xenogenic biomaterials, or a combination of them and, as the biological response of host tissue can be related to biomaterial origin, attention was focused on the interactions occurring between grafts and host tissue. 1,2 As already reported by Mangano et al, heterologous biomaterials were found to be as clinically efficient as autologous bone for their capacity of osteoconduction, even if little is known about their capability to be resorbed, and about the time they need to be fully replaced by newly formed bone tissue. 3 In fact, a biomaterial showing a too rapid resorption rate may result unsuitable for bone augmentation procedures, because it could be completely resorbed before osteogenic cells have colonized the defect; on the other hand, a biomaterial showing no resorption could cause problems to the regeneration of bone with a lower osteogenesis ability in respect to native autologous bone.…”

Anti‐adhesive and pro‐apoptotic effects of 2‐hydroxyethyl methacrylate on human gingival fibroblasts co‐cultured with Streptococcus mitis strains

“…As cell adhesion plays a critical role in cell morphology and function (Falconi et al 2007, Tetè et al 2009) and different stimuli can influence fibroblast adhesion (Liu et al 2010), fibroblast expression of pro-collagen I, a molecule involved in adhesive processes, was analysed by immunohistochemical and western blot analyses. The data strongly support pro-collagen I expression reduction in HGF samples after 48- and 72-h HEMA treatment and show perinuclear localization of protein in control samples.…”

In Vitro Behavior of Primary Human Osteoblasts Onto Microrough Titanium Surface

“…27 The high level of IL-1 and TNFa released in vitro at day 7 could resemble the inflammatory response that arises from the first interaction between an implant surface or, in general, a biomaterial with the host tissue. 28,29 However, IL-6 and PGE 2 are usually described as stimulators for osteoclast activity. 30 In particular, the latter could be responsible in vivo for the recruitment and for the osteoclastic cell activation, which is responsible of bone tissue resorption.…”