Oral squamous cell carcinoma (OSCC) is a highly aggressive malignancy with poor prognosis, mainly due to the presence of cancer stem cells (CSCs), a small subpopulation of cells that contribute to therapy resistance and tumor progression. The principal objective of this study was to investigate the role of miRNA-21 in the maintenance of cancer cell stemness and the possibility of altering it. The CD44 antigen was used as a marker for CSC isolation from oral cancer cell cultures. CD44+ and CD44− populations were sorted via magnetic separation. miRNA-21 inhibition was performed in CD44+ cells via transfection. CD44+ cells possessed a significantly higher migration and invasion potential compared to CD44− cells, higher levels of miRNA-21 (p = 0.004) and β-catenin (p = 0.005), and lower levels of BAX (p = 0.015). miRNA-21 inhibition in CD44+ cells reduced migration, invasion, and colony formation while increasing apoptosis. Stemness markers were significantly downregulated following miRNA-21 inhibition: OCT4 (p = 0.013), SOX2 (p = 0.008), and NANOG (p = 0.0001), as well as β-catenin gene (CTNNB1) (p < 0.05), an important member of WNT signaling pathway. Apoptotic activity was enhanced, with a significant downregulation of the antiapoptotic Bcl-2 (p = 0.008) gene. In conclusion, miRNA-21 plays a critical role in the regulation of oral cancer CD44+ cells properties. Targeting and inhibiting miRNA-21 in CD44+ cells could represent a promising novel strategy in OSCC treatment.

The study of the organizational kinetics in the area surrounding the transmucosal part of dental implants promises to ensure an accurate diagnosis of the healing process, in terms of osseointegration and long-term implant success. In this demonstrative work, the morphological, qualitative and quantitative characteristics of 3D images of collagen bundles obtained by synchrotron-based high-resolution X-ray tomography were analyzed. Data analysis was performed using deep learning algorithms, neural networks that were applied on multiple volumes extracted from connective portions of different patients. The neural network was trained with mutually consistent examples from different patients; in particular, we used a neural network model, U-Net, well established when applying deep learning to datasets of images. It was trained not only to distinguish the collagen fibers from the background, but also to subdivide the collagen bundles based on the orientation of the fibers. In fact, differently from conventional thresholding methods, deep learning semantic segmentation assigns a label to each pixel, not only relying on grey level distribution but also on the image morphometric (shape or direction) characteristics. With the exception of Pt2 biopsies that, as confirmed by the polarized light investigation, were shown to present an immature tissue condition, the quantity, the anisotropy degree and the connectivity density of transverse bundles were always demonstrated to be higher than for longitudinal ones. These are interesting and new data; indeed, as collagen bundles are organized in an intertwining pattern, these morphometric and 3D complexity parameters, distinguished in transversal and longitudinal directions, give precise indications on the amount and distribution of connective tissue forces exerted during the healing process.

Objectives: This in vitro study aimed assessing the remineralization potential of three commercial fluoride-based toothpastes in permanent teeth with natural white spot lesions (WSLs). A multidisciplinary approach based on Raman microspectroscopy (RMS), Scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDS), and Vickers microhardness (VMH) was exploited. Methods: N = 12 human molars with natural WSLs in the proximal-vestibular zone were selected and divided into 4 groups (n = 3) according to the different treatments: HAF (hydroxyapatite with fluoride ions); SMF (sodium monofluorophosphate with arginine); SF (sodium fluoride with enzymes), and CTRL (untreated group). All toothpastes tested contained 1450 ppm of fluoride. Teeth samples were submitted to the following protocol: a 7-day pH cycling treatment, with two daily exposures (2 min each time) to the commercial toothpastes described above. The surface micromorphology (SEM), the chemical/elemental composition (RMS and EDS), and the Vickers microhardness (VMH) were evaluated. Statistical analysis was performed. Results: A remarkable remineralization of WSLs in SEM images was observed in all treated groups compared to CTRL. In particular, HAF and SF displayed higher values of VMH, phosphates amount (I₉₆₀), crystallinity (FWHM₉₆₀), and lower ones of C/P (I₁₀₇₀/I₉₆₀) with respect to CTRL. Intermediate values were found in SMF, higher than CTRL but lower with respect to HAF and SF. As regards the Ca/P ratio, statistically significant differences (p < 0.05) were found between SF and the other groups. Conclusions: All the tested dentifrices have shown to remineralize the WSLs. SF and HAF have comparable capability in hardness recovery and crystallinity; however, SF shows the best remineralizing potential according to both micromorphological and chemical analyses. Clinical relevance The daily use of toothpastes containing hydroxyapatite partially replaced with fluoride, sodium monofluorophosphate with arginine and sodium fluoride toothpaste associated with enzymes represents a preventive, therapeutic, effective, and non-invasive tool for remineralize WSLs.

High resolution analysis of collagen bundles could provide information on tumor onset and evolution. This study was focused on the microarchitecture and biomolecular organization of collagen bundles in oral tongue squamous cell carcinoma (OTSCC). Thirty-five OTSCC biopsy samples were analyzed by synchrotron-based phase-contrast microcomputed tomography and Fourier transform infrared imaging (FTIRI) spectroscopy. PhC-microCT evidenced the presence of reduced and disorganized collagen in the tumor area compared to the extratumoral (ExtraT) one. FTIRI also revealed a reduction of folded secondary structures in the tumor area, and highlighted differences in the peritumoral (PeriT) areas in relation with the OTSCC stage, whereby a significantly lower amount of collagen with less organized fibers was found in the PeriT stroma of advanced-OTSCC stages. Interestingly, no significant morphometrical mismatches were detected in the same region by PhC-microCT analysis. These results suggest that biomolecular alterations in the OTSCC stroma temporally anticipate structural modifications of collagen bundle microarchitecture.

In a scaffold-based approach for bone tissue regeneration, the control over morphometry allows for balancing scaffold biomechanical performances. In this experimental work, trabecular geometry was obtained by a generative design process, and scaffolds were manufactured by vat photopolymerization with 60% (P60), 70% (P70) and 80% (P80) total porosity. The mechanical and biological performances of the produced scaffolds were investigated, and the results were correlated with morphometric parameters, aiming to investigate the influence of trabecular geometry on the elastic modulus, the ultimate compressive strength of scaffolds and MG-63 human osteosarcoma cell viability. The results showed that P60 trabecular geometry allows for matching the mechanical requirements of human mandibular trabecular bone. From the statistical analysis, a general trend can be inferred, suggesting strut thickness, the degree of anisotropy, connectivity density and specific surface as the main morphometric parameters influencing the biomechanical behavior of trabecular scaffolds, in the perspective of tissue engineering applications.

Effective bone tissue regeneration remains pivotal in implant dentistry, particularly for edentulous patients with compromised alveolar bone due to atrophy and sinus pneumatization. Biomaterials are essential for promoting regenerative processes by supporting cellular recruitment, vascularization, and osteogenesis. This study presents the development and characterization of a novel lithography-printed ceramic β-TCP scaffold, with a macro/micro-porous lattice, engineered to optimize osteoconduction and mechanical stability. Morphological, structural, and biomechanical assessments confirmed a reproducible microarchitecture with suitable porosity and load-bearing capacity. The scaffold was also employed for maxillary sinus augmentation, with postoperative evaluation using micro computed tomography, synchrotron imaging, histology, and Fourier Transform Infrared Imaging analysis, demonstrating active bone regeneration, scaffold resorption, and formation of mineralized tissue. Advanced imaging supported by deep learning tools revealed a well-organized osteocyte network and high-quality bone, underscoring the scaffold’s biocompatibility and osteoconductive efficacy. These findings support the application of these 3D-printed β-TCP scaffolds in regenerative dental medicine, facilitating tissue regeneration in complex jawbone deficiencies.