Background: Bone augmentation is a subject of intensive investigation in regenerative bone medicine and constitutes a clinical situation in which autogenous bone grafts or synthetic materials are used to aid new bone formation. Method: Based on a non-critical defect, Co-Cr barrier membranes were placed on six adult Fauve de Bourgogne rabbits, divided into two groups: whole blood and PRP. Three densitometric controls were performed during the experiment. The animals were euthanized at 30, 45, 60, and 110 days. The presence of newly formed bone was observed. Samples for histological studies were taken from the augmentation center. Results: External and internal bone tissue augmentation was observed in almost all cases. Significant differences between PRP- and whole blood–stimulated bone augmentation were not observed. At 60 days, bones with PRP presented higher angiogenesis, which may indicate more proliferation and cellular activity. Conclusion: PRP activates the bone regeneration process under optimized conditions by stimulation of osteoblast proliferation after six weeks, when a significant difference in cellular activity was observed. Membranes could stimulate bone augmentation at the site of placement and in the surrounding areas.

Cr-Co-Mo (ASTM F75) alloy has been used in the medical environment, but its use as a rigid barrier membrane for supporting bone augmentation therapies has not been extensively investigated. In the present study, Cr-Co-Mo membranes of different heights were placed in New Zealand white, male rabbit tibiae to assess the quality and volume of new bone formation, without the use of additional factors. Animals were euthanized at 20, 30, 40, and 60 days. Bone formation was observed in all of the cases, although the tibiae implanted with the standard membranes reached an augmentation of bone volume that agreed with the density values over the timecourse. In all cases, plasmatic exudate was found under the membrane and in contact with the new bone. Histological analysis indicated the presence of a large number of chondroblasts adjacent to the inner membrane surface in the first stages, and osteoblasts and osteocytes were observed under them. The bone formation was appositional. The Cr-Co-Mo alloy provides a scaffold with an adequate microenvironment for vertical bone volume augmentation, and the physical dimensions and disposition of the membrane itself influence the new bone formation.

Photofunctionalization of implant materials with ultraviolet (UV) radiation have been subject of study in the last two decades, and previous research on CoCrMo discs have showed good results in terms of bioactivity and the findings of apatite-like crystals in vitro. In the current study, CoCrMo domes were photofunctionalized with UV radia

Abstract-Titanium is the gold standard material in oral implantology due to its convenient properties: biocompatibility, low density, high resistance, high rigidity, excellent bone attachment and biological stability. Many researchers have proved that it is possible to improve the implant fixation and to reduce osseointegation time through surface treatments, which lead to the development of an adequate topography. In this study, discs of commercially pure titanium, grade II were subjected to sand blasting using Al 2 O 3 particles, acid etching using HF and HCl/H 2 SO 4 solutions and 600°C heat treatment during one hour. To determine in vitro behavior, samples were submerged in simulated body fluid. The obtained surface characterization was observed by scanning electron microscopy and electron probe microanalyzer. Results showed titanium as the only component of the treated surfaces, which proves acidic treatment effectiveness and an elevated decontamination; moreover, this treatment achieved a submicrometric topography that may influence on clot retention and bone matrix formation. Heat treatment samples showed a coating of crystalline agglomerations, whose elemental composition was calcium and phosphorus, apatitic kind, which follows the rough morphology of substrate.

Although there are several studies of the ultraviolet (UV) light-mediated photofunctionalization of titanium for use as implant material, the underlying mechanism is not fully understood. However, the results of in vitro and in vivo studies are very encouraging. The use of UV photofunctionalization as a surface treatment on other implant materials, as the Cr-Co-Mo alloy, has not been explored in depth. Using sandblasted Cr-Co-Mo discs, the surface photofunctionalization was studied for ultraviolet A (UVA, 365 nm) and ultraviolet C (UVC, 254 nm), and the surfaces were evaluated for their ability to sustain hydroxyapatite crystal growth through incubation in simulated body fluid for a seven-day period. The variation of the pre- and post-irradiation contact angle and surface composition was determined through the quantification of the weight percentage of Ca and P crystals by the EDAX ZAF method (EDS). Statistically significant differences (p < 0.05) were found for samples irradiated with UVA over 48 h, corresponding with hydrophilic surfaces, and the same result was found for samples exposed to 3 h of UVC. Superhydrophilic surfaces were found in samples irradiated for 12, 24 and 48 h with UVC. The decrease in the carbon content is related with the increase in the surface content of Ca and P, and vice versa over the Cr-Co-Mo surfaces.

Objective: To analyse a set of morphological features from digital radiographs (RX) and bone mineral density (BMD) values estimated from quantitative computerized tomography scans (QCT scans) of the knee joint of an osteoporotic rabbits, and to determine the relationship and correlation of these variables to be considered as an alternative diagnosis method. Methods: The knee joint of rabbits (N=9 ovariectomized and injected with of methylprednisolone sodium succinate (OVX+MPSS) and 3 sham operated healthy controls) were subjected to radiographic examination before the beginning of the study and after 6 weeks; after sacrifice, they were immediately scanned with a 64-channel CT. A set of morphological features was extracted from RX images and then subjected to Principal Component Analysis (PCA); BMD-values were calculated at different depths from the articular surface of the femur and the tibia. The selected morphological variables and the BMD values were correlated in order to determine useful information in medical diagnostics. Results: Ten morphological variables explained 80.39% of the total variability, but only some of them demonstrated significant differences between baseline and OVX+SSMP states and between OVX+SSMP and control. Spearman analysis showed higher positive and negative correlation of these parameters among them (r=0.67, 0.81, 0.83 and 1); and a moderate correlation with the BMD values (r=0.50, 0.52, 0.52 and 0.55) during the progression of osteoporosis (OP). Conclusion: The Spearman's rank test supported the overall significant correlation between both, the morphological features and BMD values, making them as a reliable alternative option to the diagnosis of osteoporosis.

During almost two decades of research in the field of Tissue Engineering and Regenerative Medicine, a variety of biomaterials and techniques have been developed, and a series of results and clinical evidence have been published to support and improve bone regeneration and augmentation processes. The latest techniques include the use of growth factors and platelet-rich plasma preparations in combination with natural or artificial scaffolds, membranes, and stem cells. However, the application of these concepts depends heavily on a favorable microenvironment for the regeneration, which is provided by the use of the bioreactor. The bioreactor is a system in which a microenvironment can be created to promote bone regeneration by providing favorable biomechanical conditions, protecting against infection, and allowing proper nutrition of the regenerating tissue by vascularization. The latest research in this field is very promising as preliminary studies have shown good results concerning bone quality and architecture. In relation to the bioreactor principle, computational modeling represents a very effective tool to predict bone ingrowth. In addition, based on the obtained results, the use of these data to prevent diseases in the human osseous-articular system is expected in the near future.

Electric fields used in bone stimulation are based on the application of direct current, but some drawbacks exist, such as the need for an external power source. Piezoelectric poly(vinylidene fluoride) (PVDF) has attracted interest for biomedical applications due to its flexibility, low toxicity, and the piezoelectric response to mechanical stimuli. This study aimed to investigate the effects of PVDF films on bone regeneration in rabbit tibias to assess the potential improvement in osteogenesis. An initial exploratory experiment was performed to determine optimal parameters for regulating the marrow blood supply. The second experiment focused on examining the effects of ultrasound stimulation on the implant's osteogenic capacity. The results showed that PVDF films have a notable impact on the extraskeletal bone formation and bone density in a secluded microenvironment with and without microperforations. At 60 days after surgery, tibias with marrow blood supply reached higher bone volumes and density and they were consistent with the cellular activity. Our results suggest that piezoelectric PVDF films have osteogenic characteristics and can be used to enhance new bone formation in a secluded space, thus reinforcing their biocompatibility nature. Additional studies are required to analyze the benefits of ultrasound stimulation.