Journal of Functional Biomaterials最新文献

The progress of digital technologies in dental prosthodontics is fast and increasingly accurate, allowing practitioners to simplify their daily work. These technologies aim to substitute conventional techniques progressively, but their real efficiency and predictability are still under debate. Many systematic reviews emphasize the lack of clinical RCTs that compare digital and traditional workflow. To address this evidence, we conducted a three-arm designed clinical RCT, which compares fully digital, combined digital, and analogic and fully analog workflows. We aimed to compare the clinical properties of each workflow regarding interproximal (IC) and occlusal contact (OC), marginal fit, impression time (IT), and patient satisfaction through a VAS scale. In total, 72 patients were included in the study. The IC and OC of the digital workflow were better than the others (p < 0.001), which obtained similar results. No difference between implant-abutment fit was observed (p = 0.5966). The IT was shorter in the digital workflow than the others (p < 0.001), which were similar. Patient satisfaction was higher in the digital workflow than in the conventional one. Despite the limitations, this study's results support better accuracy and patient tolerance of digital workflow than of conventional techniques, suggesting it as a viable alternative to the latter when performed by clinicians experienced in digital dentistry.

Objectives: This study investigated a novel strategy for improving regenerative cartilage outcomes. It combines fractional laser treatment with the implantation of neocartilage generated from autologous dynamic Self-Regenerating Cartilage (dSRC).

Methods: dSRC was generated in vitro from harvested autologous swine chondrocytes. Culture was performed for 2, 4, 8, 10, and 12 weeks to study matrix maturation. Matrix formation and implant integration were also studied in vitro in swine cartilage discs using dSRC or cultured chondrocytes injected into CO₂ laser-ablated or mechanically punched holes. Cartilage discs were cultured for up to 8 weeks, harvested, and evaluated histologically and immunohistochemically.

Results: The dSRC matrix was injectable by week 2, and matrices grew larger and more solid with time, generating a contiguous neocartilage matrix by week 8. Hypercellular density in dSRC at week 2 decreased over time and approached that of native cartilage by week 8. All dSRC groups exhibited high glycosaminoglycan (GAG) production, and immunohistochemical staining confirmed that the matrix was typical of normal hyaline cartilage, being rich in collagen type II. After 8 weeks in cartilage lesions in vitro, dSRC constructs generated a contiguous cartilage matrix, while isolated cultured chondrocytes exhibited only a sparse pericellular matrix. dSRC-treated lesions exhibited high GAG production compared to those treated with isolated chondrocytes.

Conclusions: Isolated dSRC exhibits hyaline cartilage formation, matures over time, and generates contiguous articular cartilage matrix in fractional laser-created microenvironments in vitro, being well integrated with native cartilage.

Computer-aided design and computer-aided manufacturing (CAD/CAM) techniques are based on either subtractive (milling prefabricated blocks) or additive (3D printing) methods, and both are used for obtaining dentistry materials. Our in vitro study aimed to investigate the behavior of human gingival fibroblasts exposed to methacrylate (MA)-based CAD/CAM milled samples in comparison with that of MA-based 3D-printed samples to better elucidate the mechanisms of cell adaptability and survival. The proliferation of human gingival fibroblasts was measured after 2 and 24 h of incubation in the presence of these samples using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the membrane integrity was assessed through the lactate dehydrogenase release. The level of reactive oxygen species, expression of autophagy-related protein LC3B-I, and detection of GSH and caspase 3/7 were evaluated by fluorescence staining. The MMP-2 levels were measured using a Milliplex MAP kit. The incubation with MA-based 3D-printed samples significantly reduced the viability, by 16% and 28% from control after 2 and 24 h, respectively. There was a 25% and 55% decrease in the GSH level from control after 24 h of incubation with the CAD/CAM milled and 3D-printed samples, respectively. In addition, higher levels of LC3B-I and MMP-2 were obtained after 24 h of incubation with the MA-based 3D samples compared to the CAD/CAM milled ones. Therefore, our results outline that the MA-CAD/CAM milled samples displayed good biocompatibility during 24-h exposure, while MA-3D resins are proper for short-term utilization (less than 24 h).

The management and reconstruction of critical-sized segmental bone defects remain a major clinical challenge for orthopaedic clinicians and surgeons. In particular, regenerative medicine approaches that involve incorporating stem cells within tissue engineering scaffolds have great promise for fracture management. This narrative review focuses on the primary components of bone tissue engineering-stem cells, scaffolds, the microenvironment, and vascularisation-addressing current advances and translational and regulatory challenges in the current landscape of stem cell therapy for critical-sized bone defects. To comprehensively explore this research area and offer insights for future treatment options in orthopaedic surgery, we have examined the latest developments and advancements in bone tissue engineering, focusing on those of clinical relevance in recent years. Finally, we present a forward-looking perspective on using stem cells in bone tissue engineering for critical-sized segmental bone defects.

The use of endosseous dental implants may become unfeasible in the presence of significant maxillary bone atrophy; thus, surgical techniques have been proposed to promote bone regeneration in such cases. However, such techniques are complex and may expose the patient to complications. Subperiosteal implants, being placed between the periosteum and the residual alveolar bone, are largely independent of bone thickness. Such devices had been abandoned due to the complexity of positioning and adaptation to the recipient bone site, but are nowadays witnessing an era of revival following the introduction of new acquisition procedures, new materials, and innovative manufacturing methods. We have analyzed the changes induced in gene and protein expression in C-12720 human osteoblasts by differently surface-modified TiO₂ materials to verify their ability to promote bone formation. The TiO₂ materials tested were (i) raw machined, (ii) electropolished with acid mixture, (iii) sand-blasted + acid-etched, (iv) AlTiColorTM surface, and (v) anodized. All five surfaces efficiently stimulated the expression of markers of osteoblastic differentiation, adhesion, and osteogenesis, such as RUNX2, osteocalcin, osterix, N-cadherin, β-catenin, and osteoprotegerin, while cell viability/proliferation was unaffected. Collectively, our observations document that presently available TiO₂ materials are well suited for the manufacturing of modern subperiosteal implants.

The objective was to evaluate the change in color, hardness, and roughness produced by carbamide peroxide (CP) at two different concentrations on two resins. The 16% or 45% CP was applied to 66 resin discs with and without Bis-GMA. The color was measured with a spectrophotometer, and ΔE_ab and ΔE₀₀ were calculated. Microhardness tester and SEM were used. In both composites, the a* and b* coordinates tended to be red and yellow, respectively, and were significant in the Bis-GMA group (p < 0.05). The ΔE_ab and ΔE₀₀ were higher in the composite with Bis-GMA, regardless of the treatment received (p < 0.05). The microhardness was reduced in both composites regardless of the PC concentration compared to the control (p < 0.05). The 45% CP reduced the microhardness in the resin group with Bis-GMA compared to 16% CP (p < 0.001) but was not significant in the resin without Bis-GMA (p = 1). An increase in roughness was directly proportional to the concentration of CP, and it was more notable in the composite without Bis-GMA. The composite with Bis-GMA showed a greater tendency to darken than the one without Bis-GMA. The surface hardness of the composite was reduced in both composites and was not influenced by CP concentration in the composite without Bis-GMA. Bleaching is a common procedure nowadays. It is important to know how CP affects composites to establish a prognosis of the treatments in terms of color change, roughness, and hardness.

This contribution gives basic information about the mechanical behavior of the facial part of the human skull cranium, i.e., the splanchnocranium, associated with external loads and injuries caused mainly by brachial violence. The main areas suffering from such violence include the orbit, frontal, and zygomatic bones. In this paper, as a first approach, brachial violence was simulated via quasi-static compression laboratory tests, in which cadaveric skulls were subjected to a load in a testing machine, increasing till fractures occurred. The test skulls were also used for research into the dynamic behavior, in which experimental and numerical analyses were performed. A relatively high variability in forces inducing the fractures has been observed (143-1403 N). The results lay the basis for applications mainly in forensic science, surgery, and ophthalmology.

Yeasts resistant to antifungals have become an increasing risk to human health. One of the best antimicrobial properties is reported to be present in silver nanoparticles (AgNPs); however, little is known about the antimicrobial potential of AgNPs produced using thermophilic bacteria. How AgNPs cause cell death is different depending on the type of the cell, and the mode of death induced is cell-type specific. Apoptosis, one of the types of regulated cell death, can be extremely useful in the fight against infection because surrounding cells that have phagocytic activity can efficiently absorb the apoptotic bodies formed during apoptosis. In the course of this work, for the first time, comprehensive antifungal studies of AgNPs were performed using thermophilic Geobacillus spp. bacteria against Candida guilliermondii, also with the addition of the model yeast Saccharomyces cerevisiae. The determined minimal inhibitory concentrations (MICs) were 10 μg/mL against C. guilliermondii and 50 μg/mL against S. cerevisiae for Geobacillus sp. strain 25 AgNPs, and for Geobacillus sp. 612 the MICs were 5 μg/mL and 25 μg/mL, respectively. It was shown for the first time that the exposure of the yeast cells leads to caspase activation in both S. cerevisiae and C. guilliermondii after exposure to Geobacillus spp. AgNPs. Also, a statistically significant change in the number of cells with permeable membranes was detected. Moreover, it was shown that the antimicrobial effect of the AgNPs is related to ROS generation and lipid peroxidation in C. guilliermondii yeast.