Giuseppina Rizzo

The International Journal of Molecular Sciences retracts the article, “Differential Expression of Nitric Oxide Synthase Isoforms nNOS and iNOS in Patients with Non-Segmental Generalized Vitiligo”

Introduction: This preliminary in vitro study aims to evaluate the application of micro-CT in analyzing the microstructural coupling between dental implant fixtures and prosthetic abutments, with an emphasis on understanding the effectiveness and limitations of this technique in dental implantology. Materials and Methods: A search of PubMed, MEDLINE, and the Cochrane Library up to May 2024 identified eight relevant studies that examined different facets of dental implantology, such as osseointegration, implant stability, and the comparative accuracy of micro-CT versus other imaging techniques. A comparative micro-CT radiographic analysis was performed on five different implant fixtures with respective prosthetic and healing abutments, by using SkyScan1174 micro-CT. Results: The reviewed studies demonstrated that micro-CT is reliable for assessing bone quality, implant stability, and the microstructural integrity of dental implants. Micro-computed tomography (micro-CT) studies reveal bone–implant contact (BIC) ratios of 40–80%, bone volume per total volume (BV/TV) values of 20–60%, and detect microgaps as small as 0.3 µm, highlighting its high-resolution capability (5–10 µm) for detailed implant analysis. The comparative analysis of the implant fixtures analyzed the implant–abutment connection, highlighting the relevance of implant design for ensuring stability. Conclusions: Micro-CT analysis has proven to be a valuable tool for evaluating the intricate microstructural properties of dental implants, offering insights into implant stability, bone quality, and osseointegration. The literature reviewed highlights consistent findings that underscore micro-CT’s accuracy and reliability in capturing high-resolution data, suggesting its potential as a standard imaging modality in implant research and clinical assessment.

Inflammatory bowel diseases (IBDs) represent multifactorial chronic inflammatory conditions of the gastrointestinal tract. The main IBDs are Crohn’s disease (CD) and ulcerative colitis (UC). CD may cause perforation, stricture or transmural inflammation, which can occur discontinuously in the entire gastrointestinal tract (GIT). UC leads to mucosal inflammation as well as mucosal atrophy in the rectum and the colon. Innate immunity is considered the first line of defense against microbial invasion; among Toll-like receptors, TLR2 is the most important for defense against mycobacterial infection. TLR2 has been reported to have a lot of functions in infectious diseases and in other pathologies, such as chronic and acute inflammatory diseases. Alfa-Smooth Muscle Actin (α-SMA) is an important biomarker in IBDs. All myofibroblasts express α-SMA, which has been found to be upregulated in CD and UC. Paraformaldehyde-fixed intestinal tissues, from patients with CD and patients with UC, were analyzed by immunostaining for TLR2 and α-SMA. Our results showed that, in the samples obtained from UC patients with inflamed mucosa, TLR2-positive epithelial cells concentrated on the mucosal surface and scattered immune cells in the connective tissue; furthermore, numerous α-SMA-positive cells (subepithelial myofibroblasts) were detected in the lamina propria and around glands, while some myofibroblasts co-localizing with α-SMA and TLR2 could be inflammatory macrophages. In CD patients, TLR2-positive enterocytes and α-SMA-positive myofibroblasts in the lamina propria of the villus have been observed. In control samples, a low positivity to α-SMA and TLR2 was observed in subepithelial myofibroblasts and scattered immune cells of the lamina propria. These data showed the recall of α-SMA-positive myofibroblasts during the inflammatory state; in addition, TLR2 expression has been observed to change in the intestinal epithelium in IBDs, demonstrating that alterations in the innate system response may contribute to the pathogenesis of these diseases.

The extracellular matrix of the articular disc in a temporomandibular joint (TMJ) is composed mainly of collagen I and elastin. The collagen is important for resisting tensile forces, while the elastin is responsible to maintain the shape after deformation. We studied the orientation of collagen and elastin in a normal human temporomandibular joint disc by light microscopy, immunofluorescence and scanning electron microscopy. Our results demonstrated that collagen and elastin run parallel to each other in the intermediate zone with an anteroposterior orientation. From here, the orientation of two fibers groups changes into a disordered arrangement in the transition zone. Numerous elastic fibers cross with the collagen fibers, defining an interwoven knitted arrangement. The evaluation of the disc–condyle relationship shows that the medial margin of the articular disc is inserted directly at the superficial layer of the mandibular condylar cartilage. Therefore, the tensile properties of the TMJ disc are expressed in the directions corresponding to the orientation of the collagen fibers, and the complex orientation of elastin with the collagen determines the maintaining of the shape after the stresses by the joint movements. Moreover, the direct anatomical relationship between the articular disc and the mandibular condyle makes a decisive contribution to the understanding of TMJ movements.

The temporomandibular joint (TMJ) is a bilateral synovial articulation stabilized by several anatomical structures such as ligaments. The existence of articular capsule reinforcement structures have been described in the lateral and medial sides of disc which have been defined as collateral ligaments, lateral and medial. Despite that, some macroscopic observations support that these collateral ligaments do not belong to the articular capsule but they belong to the disc. By that, the aim of the present work was to evaluate morphological aspects of TMJ from cadaveric frozen heads by histological and immunofluorescence techniques in order to verify the origin and insertion of lateral and medial collateral ligaments. Results show that both lateral and medial ligaments origin from the disc and insert directly to the articular cartilage of mandibula condyle. These data open a new approach in the study of human TMJ.

Background: Repairing a restoration is a more advantageous and less invasive alternative to its total makeover. The aim of this study was to analyze the effects of chemical and mechanical surface treatments aimed at increasing the roughness of a supra-nano composite resin. Methods: 27 cylindrical blocks of microhybrid composite were made. The samples were randomly divided into nine groups (n = 3). The samples’ surface was treated differently per each group: acid etching (35% H₃PO₄, 30 s and 60 s), diamond bur milling, sandblasting and the combination of mechanical treatment and acid etching. The samples’ surface was observed by a scanning electron microscope (SEM) and a confocal microscope for observational study, and surface roughness (R_a) was recorded for quantitative analysis. Results: The images of the samples sandblasted with Al₂O₃ showed the greatest irregularity and the highest number of microcavities. The surfaces roughened by diamond bur showed evident parallel streaks and sporadic superficial microcavities. No significant roughness differences were recorded between other groups. The difference in roughness between the control group, diamond bur milled group and sandblasted group was statistically significant. (p < 0.01). Comparison between the diamond bur milled group and the sandblasted group was also significant (p < 0.01). Conclusion: According to our results, sandblasting is the best treatment to increase the surface roughness of a supra-nano composite.

Introduction The clinical relevance of the anatomy and variations of the anterior ethmoidal artery (AEA) is outstanding, considering its role as a landmark in endoscopic surgery, its importance in the therapy of epistaxis, and the high risks related to iatrogenic injuries. Objective To provide an anatomical description of the course and relationships of the AEA, based on direct computed-tomography (CT)-based 3D volume rendering. Methods Direct volume rendering was performed on 18 subjects who underwent (CT) with contrast medium for suspected cerebral aneurism. Results The topographical location of 36 AEAs was assessed as shown: 10 dehiscent (27.8%), 20 intracanal (55.5%), 6 incomplete canals (16.7%). Distances from important topographic landmarks are reported. Conclusion This work demonstrates that direct 3D volume rendering is a valid imaging technique for a detailed description of the anterior ethmoidal artery thus representing a useful tool for head pre-operatory assessments.

Introduction. The use of equine bone blocks is widely reported for bone augmentation techniques. The block must be shaped according to the form of the defect that should be regenerated. The shaping could be performed by hand before or during the surgery, in a sterile ambient, or using a CNC milling machine that could not be sterile. The aim of our study was to evaluate if a steam sterilization could provide a medical grade sterilization of the blocks and to evaluate if bone microstructure and collagen structures change after different steam sterilization protocols provided by mainstream autoclave. Materials and Method. Two blocks of equine bone were divided into 16 samples. 1 sample was used as control and not submitted to any treatment. 15 samples were infected with a Streptococcus faecalis bacterial culture. The samples were singularly packed, randomly divided into 3 groups, and submitted to autoclave sterilization on the same device. The groups were submitted to a sterilization cycle (Gr. A: 121°C, 1,16 bar for 20′; Gr. B:134°C, 2,16 bar for 4′; Gr. C: 134°C, 2,16 bar for 3.30 min.). 2 samples for each group were evaluated for the sterility. 3 samples for each group were observed at SEM to notice the macro- and microstructure modification and to confocal microscope to observe the collagen. Results. All samples were sterile. The SEM evaluation showed, in all groups, a preserved morphological structure. Confocal microscope evaluation shows that the collagen structure appears to be more uniform and preserved in group C. Conclusion. Data show that autoclave steam sterilization could be reliable to obtain sterilization of equine bone blocks.