Search Results (149)

Background: The role of collagen membrane fixation during guided bone regeneration (GBR) remains debatable, particularly in post-extraction sockets with buccal defects and concomitant immediate implant placement. This study evaluated whether or not fixation with titanium pins improved regenerative outcomes. Methods: Six adult Beagle dogs received bilateral extractions of the fourth mandibular premolars. An implant was immediately placed in both the distal alveoli, and standardized buccal bone defects (5 mm height, 3–2 mm width) were prepared. All defects were filled with a slowly resorbing equine xenograft and covered by a resorbable pericardium membrane. At the test sites, the membrane was apically fixed with pins, while no fixation was applied to the control sites. After 3 months of healing, histomorphometric analyses were performed. Results: The vertical bone gain of the buccal crest was 3.2 mm in the test sites (pin group) and 2.9 mm in the control sites (no-pin) (p > 0.754). No significant difference was found in terms of bone-to-implant contact (BIC). However, residual graft particles were located significantly more coronally in the pin group compared to the no-pin group (p = 0.021). Morphometric analyses revealed similar new bone formation within the groups, but with higher amounts of residual xenograft and soft tissue in the pin group. Conclusions: Membrane fixation did not significantly enhance vertical bone gain, and although the slightly higher regeneration in the pin group (3.2 mm vs. 2.9 mm) may hold clinical relevance in esthetically sensitive areas and osseointegration, it appeared to limit coronal migration of the grafting material. Full article

Background: The combination of polynucleotides and hyaluronic acid with bovine bone grafts in maxillary sinus lift procedures appears to be a promising strategy to enhance bone regeneration. This study aimed to analyze implant osseointegration, bone repair and sinus mucosa integrity using Bio-Oss^® and Hyaluronic Acid-Polynucleotide Gel (Regenfast^®) in maxillary sinus augmentation in rabbits. Methods: Sinus floor elevation was performed in 12 rabbits, with one implant placed per sinus simultaneously. In the control group, sinuses were grafted with deproteinized bovine bone mineral (Bio-Oss^®) alone; in the test group, Bio-Oss^® was combined with Regenfast^®. Two histological slides were obtained per sinus after 2 weeks (six animals) and 10 weeks (six animals): one from the grafted area alone (non-implant sites), and one from the implant site. Primary outcome variables included the percentage of newly formed bone, the extent of implant osseointegration, and the number of sinus mucosa perforations caused by contact with graft granules. Results: After 10 weeks of healing, the test group showed a significantly higher percentage of new bone formation (37.2 ± 6.7%) compared to the control group (26.8 ± 10.0%; p = 0.031); osseointegration extended to the implant apex in both groups; fewer sinus mucosa perforations were observed in the test group (n = 5) than in the control group (n = 14). Conclusions: The addition of Regenfast^® to Bio-Oss^® granules promoted enhanced bone regeneration within the elevated sinus area and was associated with a lower incidence of sinus membrane perforations compared to the use of Bio-Oss^® alone. Full article

Background: Peri-implantitis, the most prevalent cause of implant failure, is a multifaceted issue that is influenced by various factors that promote biofilm formation around the implant. Although various innovative methods for microbiological decontamination of dental implants exist, a universally accepted standard protocol has not yet been established. However, the potential of a device that generates an electric current (Ximplant^®) in reducing the survival of microorganisms within the biofilm is a promising development. Methods: In this in vitro study, five dental implants, contaminated using a microbial culture from a sample of saliva of a patient suffering from peri-implantitis, were decontaminated using the Ximplant^® peri-implantitis protocol. The experimental conditions included a simulated peri-implant site and a subsequent fluorescent assessment of the Live/Dead microbial population. Results: The qualitative and quantitative image analyses showed a predominant dead light signal on the treated sample, demonstrating the potential efficacy of applying the electrostatic field to the contaminated implant surface in reducing the viability of the microorganisms within the biofilm around dental implants. Conclusions: These findings could inspire a new era in peri-implantitis treatment. Full article

The absence of interdental papillae in dental prosthetics often leads to unsatisfactory esthetic outcomes, such as black triangles and elongated clinical crowns. While previous research has demonstrated that papillae can regenerate in a coronal direction, the underlying mechanisms remain incompletely understood. Several theories have been proposed to explain this phenomenon, but no clear cause–effect relationship has been established among the various factors involved in spontaneous papilla growth around implants. This study aims to identify and classify the factors influencing this process. Various potential contributors were analyzed, including adjacent elements, buccal–lingual papilla width, contact point position, convergent neck design, crown overcontour, intraoral negative pressure, and others. To systematically organize these factors, a modified Overton Window and a mind map were employed. The factors were categorized as cause-related, essential, or influencing based on the collective opinion of the research group following a comprehensive review of the relevant literature. In the absence of clear evidence supporting a definitive cause–effect relationship, Occam’s Razor (the principle of parsimony) was applied to identify the most plausible cause-related factors. Full article

Background: Cortical and marrow bone layer have different histomorphometric features. The traditional implant insertion technique provides for fixture stabilization through the cortical area. However, this approach has been found to result in an overstress of this bone layer, which may lead to resorption. Therefore, the aim of this study was to evaluate bone healing by applying two different implant site preparation protocols across various bone densities. Materials and Methods: One implant was placed in each femur and tibia of the rabbits (four implants per animal), using two distinct site preparation methods: drilling alone or drilling followed by osteotomes (funnel technique). Three regions around the implant were evaluated: cervical, marrow, and apical. The study included 12 rabbits, divided into two groups of 6 animals each, which were euthanized at 3 and 6 weeks, respectively (n = 6 per group). Results: In the cervical region of both femur and tibia, no marginal bone resorption could be detected. Similar BIC% (bone-to-implant contact percentages) were observed for funnel and drill sites after 3 weeks and 6 weeks of healing. Differences, though not statistically significant, ranged between 2.8% and 4.7%. However, higher BIC% values were observed in the femora compared to the tibia in both periods. Conclusions: No marginal bone loss was observed in both techniques. No statistically significant differences in bone resorption or bone-to-implant contact around the implant collar were observed when comparing two implant site preparation protocols across various bone densities. The use of osteotome did not influence the healing in the marrow region. Full article

Background: Osseointegrated implants are essential for rehabilitating edentulous patients, but critical bone defects remain challenging. Guided bone regeneration (GBR) with barrier membranes is an effective approach. This study evaluated a 3D printed membrane made from acrylated epoxidized soybean oil (AESO) combined with a xenogeneic graft for GBR in critical-size defects. Methods: Forty-eight male Sprague Dawley rats (150 g) were assigned to four groups: a negative control group (NC, blood clot only), a positive control group (PC, biomaterial without membrane), a negative test group (NT, blood clot with membrane), and a positive test group (PT, biomaterial with membrane). Results: The PT group showed the highest bone volume and superior bone maturation compared to the other groups. Bone quality parameters (Tb.N, Tb.Th) indicated enhanced maturation in the groups using the membrane. A histological analysis confirmed centripetal bone formation. Conclusion: The AESO-based membrane provided mechanical support and controlled resorption, addressing collagen membrane limitations. Its combination with the GTO^® graft material enhanced osteoconduction, bone formation, and bone quality, highlighting its potential for complex bone defect reconstructions. Full article

Background: This investigation focused on the influence of collagen on the integrity of the Schneiderian membrane during maxillary sinus augmentation in a rabbit model. The aim of this study was to elucidate the relationship between membrane integrity and bone regeneration in augmented maxillary sinuses using collagenated and non-collagenated grafts, through detailed histological and histomorphometric analyses. Methods: In this forward-looking, randomized, split-mouth design, bilateral maxillary sinus augmentation was conducted on 12 rabbits. One sinus was filled with deproteinized bovine bone material (DBBM) as the grafting material (non-collagenated; control), while a combination of DBBM particles integrated with 10% porcine-derived type I collagen was used in the contralateral sinus (collagenated; test). Histological analyses were carried out following healing periods of 2 and 12 weeks. Results: At the 2-week time point, six sites of thinned mucosa (<40 µm) and no perforations were observed in the collagenated group, while twenty-one thinned mucosa sites (p = 0.027 between test and control) and two perforations (p = 0.175 between test and control) were found in the non-collagenated group. After 12 weeks of healing, the number of sites with thinned mucosa was 20 in the collagenated group and 19 in the non-collagenated group, with four perforations observed in each group. These perforations were distributed across three sinuses in the collagenated group and two sinuses in the non-collagenated group. No statistically significant differences were found between the groups. Conclusions: The addition of 10% collagen to deproteinized bovine bone mineral initially provided protection against mucosal thinning and perforation after 2 weeks of healing. However, by week 12, this protective effect diminished, resulting in similar rates of mucosal thinning and perforations in both groups. Full article

Background/Objectives: HER2-positive breast cancer (HER2⁺BC) is an aggressive subtype, with neoadjuvant treatment (NAT) aiming to achieve a pathological complete response (pCR) to improve long-term outcomes. Trastuzumab emtansine (T-DM1) has been established as the standard of care in the adjuvant setting for HER2⁺BC patients who do not obtain pCR. The ATD study aimed to evaluate the real-world tolerability of T-DM1 in this setting. The secondary objective was to assess the effectiveness. Methods: This was a multicenter, retrospective study across 24 Italian oncology centers, including 410 patients with HER2⁺BC treated with adjuvant T-DM1 following a lack of pCR after NAT. Patient characteristics, NAT regimens, and surgical outcomes were recorded. Tolerability was assessed by documenting adverse events (AEs) according to the CTCAE (v5.0). Preliminary effectiveness was evaluated in terms of relapse-free survival (RFS) and overall survival (OS). Results: Overall, 228 patients (55.6%) experienced at least one AE related to T-DM1, with 4.9% experiencing grade 3 or higher AEs. The most common AEs were hepatotoxicity (18.5%) and thrombocytopenia (17.6%). T-DM1 was discontinued in 10.0% of patients due to toxicity. After a median follow-up of 25 months, 31 relapse events (7.6%) and 22 deaths (5.4%) were reported. The preliminary incidence of RFS and OS events was similar between patients who completed the T-DM1 course and those who discontinued it early. Conclusions: T-DM1 demonstrated a manageable safety profile, and the adverse events were consistent with those reported in randomized trials. The data are not yet sufficient to allow for a formal analysis of RFS and OS, and long-term follow-up is required. Full article

Background: A comprehensive investigation to associate the use of polynucleotides and hyaluronic acid with bovine bone in maxillary sinus lift procedures in rabbits has not been performed yet. The aim was to evaluate the influence of this novel association on the processes of bone regeneration in maxillary sinus augmentation. Methods: In this prospective, randomized, within-animal model, maxillary sinus augmentation was performed bilaterally in 12 rabbits. Deproteinized bovine bone material (DBBM) was used as filler material. A hyaluronic acid–polynucleotide gel was aggregated at the test site. Histological evaluations were performed after 2 and 10 weeks of healing. Results: After 2 weeks of healing, similar amounts of new bone were observed at both the control (7.7 ± 4.3%) and test sites (8.1 ± 3.8%; p = 0.697). Bone formation was observed predominantly along the osteotomy margins and adjacent sinus walls. After 10 weeks of healing, the total new bone fraction reached 28.0 ± 10.1% at the control sites and 27.3 ± 10.5% at the test sites (p = 0.563). Multiple perforations of the sinus mucosa were observed in both groups when in contact with the biomaterial granules. Conclusion: The present study failed to demonstrate a positive effect on bone formation when incorporating hyaluronic acid–polynucleotide gel (Regenfast) into a xenograft for maxillary sinus augmentation. Additionally, the use of this gel did not mitigate the occurrence of thinned mucosa or reduce the risk of subsequent sinus mucosa perforation. Full article

Purpose: Single-agent immune checkpoint inhibitor (IO) therapy is the standard for non-oncogene-addicted advanced non-small cell lung cancer (aNSCLC) with PD-L1 tumor proportion score ≥ 50%. Smoking-induced harm generates high tumor mutation burden (H-TMB) in smoking patients (S-pts), while never-smoking patients (NS-pts) typically have low TMB (L-TMB) and are unresponsive to IO. However, the molecular characterization of NS-pts with H-TMB remains unclear. Experimental design: Clinical data of 142 aNSCLC patients with PD-L1 ≥ 50% treated with first line pembrolizumab were retrospectively collected. Next-generation sequencing was performed using the FoundationOne^®CDx assay to correlate genomic alterations with clinical characteristics and response outcomes. Detected mutations were classified into eleven main pathways and enrichment analysis identified patient subgroups based on mutated pathways. Additionally, a patient similarity network was constructed to analyze molecular characterization. Results were validated using data from 853 aNSCLC patients in POPLAR and OAK trials. Results: Among the patients, S-pts had higher TMB than NS-pts. Interestingly, 11 (8%) NS-pts exhibited H-TMB and were enriched in β-catenin/Wnt and DDR pathway mutations. DDR pathway mutations were confirmed to be enriched in NS-pts with H-TMB using data from POPLAR and OAK trials. In the real-world cohort, the NS/H-TMB subgroup with DDR pathway mutations demonstrated improved IO outcome. Patient similarity network analysis confirmed the clustering of NS/H-TMB patients with DDR mutations and their association with improved overall survival in both the real-world cohort and the trials. Conclusions: The DDR signature has a potential role as an additional generator of H-TMB in NS-pts. This subgroup of IO-responsive NS-pts may have better prognosis. Our findings suggest that DDR-based mutational profiling may help identify NS-pts who could benefit from IO therapy. Full article

A bluish green chalcedony (a micro to crypto polycrystalline form of silica) from Africa has been marketed with the trademark AQUAPRASE^TM. A multimethodological approach, combining gemological analyses, thin section examination, scanning electron microscopy, X-ray powder diffraction, Raman spectroscopy, and trace elements chemical analyses by LA–ICP–MS, was carried out to characterize this material from a gemological and mineralogical point of view. The chalcedony samples consist of a mixture of quartz and moganite, as shown by the X-ray powder diffraction analysis and Raman spectroscopy. “Aquaprase” showed a strong microstructural zoning in terms of grain size, from macrocrystalline to micro and crypto, and morphology. Trace element variations correlated well with the different colored areas of the samples. In particular, the main chromophore ion present in the bluish green areas of the “aquaprase” chalcedony was chromium, followed by iron and nickel, so this chalcedony could be included in the group of chromium-bearing chalcedony. Rayleigh light scattering contributed to the blue hue of the gems. Full article

The solution to inverse problems is crucial for model calibration and to provide a good basis for model results to be reliable. This paper is based on a recently proposed conceptual framework for the development and application of mathematical models that require the solution of forward and inverse problems. The focus of this paper is on the discussion of some terminology related to the results of forward problems and their reanalysis, on the use of the proposed framework to revise and generalise some methods of solutions of the inverse problem, and to provide a non-standard insight in some aspects about the Bayesian approach to model calibration. Full article

Background: To prevent excessive compression of the cortical layer, which can lead to marginal bone loss, various companies have introduced specialized drills. However, these drills often lack the necessary precision, as the operator’s hand may neither be stable enough to prevent ovalization and over-widening nor precise enough to maintain coaxial alignment. Therefore, the aim of this study was to develop a device capable of achieving calibrated cortical preparation in terms of both dimension and coaxiality. Methods: A machining technology based on drilling principles was employed to create the device. Results: Nine blades were incorporated between the transmucosal neck and the implant threads, enabling the blades to cut the cortical bone coaxially during the implant insertion process. Conclusions: The primary goal of this study was to develop an implant capable of achieving calibrated cortical bone preparation, ensuring both precise dimensional control and coaxial alignment. This design incorporates integrated blades that allow for controlled cortical decompression, helping to manage radial compressive stresses during implant placement. Although the experimental studies cited were conducted independently of this research, they validate the functional efficacy of this implant design, demonstrating its ability to promote osseointegration and preserve marginal bone. The results suggest that this implant configuration holds the potential for improving clinical outcomes, particularly in cases where bone quality or density poses challenges to implant stability. Full article

Antimony is one of the world’s scarcest metals and is listed as a Critical Raw Material (CRM) for the European Union. To meet the increasing demand for metals in a sustainable way, one of the strategies that could be implemented would be the recovery of metals as by-products. This would decrease the amount of hazardous materials filling mining dumps. The present study investigates the potential for producing antimony as a by-product at the Olympias separation plant in Northern Greece. This plant works a skarn mineralization that shows interesting amounts of Sb. Boulangerite (Pb₅Sb₄S₁₁) reports on Pb concentrate levels reached 8% in the analyzed product. This pre-enrichment is favorable in terms of boulangerite recovery since it can be separated from galena through froth flotation. Boulangerite distribution in the primary ore is quite heterogeneous in terms of the inclusion relationships and grain size. However, a qualitative assessment shows that the current Pb concentrate grain size is too coarse to successfully liberate a good amount of boulangerite. The use of image analysis and textural assessments is pivotal in determining shape factors and crystal size, which is essential for the targeting of flotation parameters during separation. The extraction of antimony as a by-product is possible through a two-step process; namely, (i) the preliminary concentration of boulangerite, followed by (ii) the hydrometallurgical extraction of the antimony from the boulangerite concentrate. The Olympias enrichment plant could therefore set a positive example by promoting the benefits of targeted Sb extraction as a by-product within similar sulfide deposits within the European territory. Full article

In art-historical terms, a self-portrait in assistenza refers to an artist having inserted their own likeness into a larger work. In Renaissance-era art, more than 90 examples have been identified, famously including Botticelli’s Adoration of the Magi (c. 1478/1483). There, Botticelli glances out from the painting, making direct eye contact with the viewer, a feature that appears in other self-portraits of the type. In ancient Egypt, it was not commonly accepted that an artist would lay claim to it, especially when the work’s scale imposed diversification of tasks to be performed or teamwork organized on a workshop basis. This article will present evidence discovered in the Chapel of Hatshepsut in her temple at Deir el-Bahari that can be interpreted as a self-portrait in assistenza and indicates that Djehuty, Overseer of the Treasury under Hatshepsut, took the lead role there. If this identification is valid, the room’s decoration gains an additional layer of meaning and may be “read” in terms of Djehuty’s message, comparable to Botticelli gazing out from his Adoration of the Magi. This ancient Egyptian case will illustrate how that artist-designer, in interweaving subtle indicators of his involvement in the work, expresses awareness both of his intellectual skills and of his pride in creation. Full article