Control Discs Research Articles

Superior photocatalytic degradation of pharmaceuticals and antimicrobial Features of iron-doped zinc oxide sub-microparticles synthesized via laser-assisted chemical bath technique

Addressing the dual challenges of antimicrobial resistance and pharmaceutical contamination in wastewater is crucial for global health and environmental preservation. Predictions estimate up to 10 million annual deaths by 2050 due to antimicrobial resistance, underscoring the urgent need for innovative solutions. This study explores the potential of zinc oxide Sub-Microparticles (ZnO SMPs) doped with iron (Fe) to enhance the photocatalytic degradation of pharmaceutical compounds in water and improve antimicrobial efficacy. A green laser-assisted chemical bath synthesis method created ZnO SMPs with varying Fe dopant concentrations (1 %, 1.5 %, and 3 %). The synthesized Sub-Microparticles underwent rigorous structural analysis using X-ray diffractometry, SEM, EDX, FTIR, and UV–visible spectrophotometry techniques. Their photocatalytic performance was evaluated in the degradation of paracetamol under blue laser light, and their antimicrobial properties were assessed following CLSI guidelines. Structural analyses confirmed the hexagonal wurtzite structure of ZnO SMPs, with noticeable changes due to Fe doping, including a transition from sub-microrods to sub-microsheets and a redshift in the optical band gap. Photocatalytic tests revealed a significant enhancement in paracetamol degradation efficiency, increasing from 53.41 % with pure ZnO to 98.99 % with 3 % Fe-doped ZnO in 50 min. Antimicrobial assays demonstrated an increased inhibitory effect against pathogens, with Fe-doped ZnO outperforming control discs. This study substantiates the potential of Fe-doped ZnO SMPs in wastewater treatment and antimicrobial applications, showcasing significant improvements in photocatalytic degradation of pharmaceutical compounds and antimicrobial efficacy. The findings underscore the importance of continuing research in this domain for environmental and public health benefits.

Dental Color-Matching Ability: Comparison between Visual Determination and Technology.

The choice of the correct color is of paramount importance in esthetic dentistry; however, there is still no consensus on the best technique to determine it. The aim of the present study is to compare the accuracy of a recently introduced colorimeter in shade matching with human vision. In addition, possible variables affecting color-matching by human eye have been analysed. 18 disc-shaped composite samples with identical size and shape were produced from a composite flow system (Enamel plus HriHF, Micerium): Nine were considered control samples (UD 0-UD 6), and nine were test samples with identical flow composite shade to the control ones. Parallelly, 70 individuals (dental students and dental field professionals) were individually instructed to sit in a dark room illuminated with D55 light and to perform visual shade matching between control and test discs. An error matrix containing ΔE94 between control and test discs was generated, containing four match-clusters depending on perceptibility and acceptability thresholds. The frequency and severity of errors were examined. The colorimeter achieved a 100% perfect matching, while individuals only achieved a 78%. A higher occurrence of mismatches was noted for intermediate composite shades without a statistically significant difference. No statistically significant differences were reported for age, sex, and experience. A statistically significant difference was present among the Optishade match and the visual determination. The instrumental shade-matching evaluation proved to be significantly more reliable than the human visual system. Further research is needed to determine whether the same outcomes are achieved in a clinical setting directly on patients.

Repellent potential of agroecological extracts: Exploring their efficacy against the leaf‐cutting ant Acromyrmex subterraneus in the laboratory

AbstractThe increasing restrictions on commercial toxic baits for controlling leaf‐cutting ants have started a “gold rush” for alternative compounds, with agroecological extracts emerging as a promising option. Here, we tested for the first time the repellent effects of concentrated and diluted ant extracts and cow urine solution on laboratory colonies of Acromyrmex subterraneus (Forel) (Hymenoptera: Formicidae). The agroecological extracts preparation and application followed the information provided by peasants from the Movimento dos Trabalhadores Rurais Sem Terra in Brazil who carry out agroecology. First, we applied the agroecological extracts in the middle segment of the upper path of a foraging trail to determine whether they act as a chemical barrier. All agroecological extracts induced the deviation of the foraging flow from the upper path to the lateral path. However, only the concentrated ant extract reduced the leaf delivery rate. Also, we applied the agroecological extracts directly on the leaf disks and conducted a paired selection test. The proportion of transported leaf disks with concentrated ant extract and cow urine solution was lower than that of control disks. We suggest that the observed repellent efficacy of the concentrated ant extract may stem from its content of chemical compounds belonging to the same chemical group as the alarm pheromones found by other Acromyrmex species. As for the cow urine solution, we attribute its repellent effect to the presence of urea. Our findings highlight a significant repellent potential of the concentrated ant extract and cow urine solution for leaf‐cutting ants, which may be applied both on foraging trails and on leaves of cultivated plants.

Effect of Zeolite Incorporation on the Ion Release Properties of Silver-Reinforced Glass Ionomer Cement.

Zeolite can release antimicrobial silver ions in a targeted and controlled manner for an extended time, selectively inhibiting the growth of pathogenic oral bacteria when added to dental materials. The objective of this study was to investigate the effect of the addition of zeolite to silver-reinforced glass ionomer cement on the release of silver ions over time. Five concentrations of silver-zeolite (0%, 0.5%, 1%, 2%, 4% wt) were incorporated into silver-reinforced GIC in the form of 10 mm × 2 mm circular disks (n = 5). The disks were incubated in deionized water at 37 °C and ion release from the samples was measured at 1, 2, 7, and 30 days after immersion by inductively coupled atomic emission spectroscopy. Incorporating silver-zeolite increased silver ion release from silver-reinforced GIC disks compared to the control disks (p < 0.05), while incorporating zeolite alone had no effect. Higher concentrations of added silver-zeolite resulted in increased silver ion release. Sustained silver ion release was observed for up to 30 days. Adding silver-zeolite to silver-reinforced GIC may enhance its extended antibacterial effect in the oral cavity.

Viability and Proliferation Assessment of Gingival Fibroblasts Cultured on Silver Nanoparticle-Doped Ti-6Al-4V Surfaces.

To investigate the biocompatibility of silver nanoparticle (AgNP)-doped Ti-6Al-4V surfaces by evaluating the viability and proliferation rate of human gingival fibroblasts (HGFs)-as the dominant cells of peri-implant soft tissues-seeded on the modified surfaces. AgNPs (sizes 8 nm and 30 nm) were incorporated onto Ti-6Al-4V specimen surfaces via electrochemical deposition, using colloid silver dispersions with increasing AgNP concentrations of 100 ppm, 200 ppm, and 300 ppm. One control and six experimental groups were included in the study: (1) control (Ti-6Al-4V), (2) 8 nm/100 ppm, (3) 8 nm/200 ppm, (4) 8 nm/300 ppm, (5) 30 nm/100 ppm, (6) 30 nm/200 ppm, and (7) 30 nm/300 ppm. HGF cell primary cultures were isolated from periodontally healthy donor patients and cultured in direct contact with the group specimens for 24 and 72 hours. The cytotoxicity of AgNP-doped Ti-6Al-4V specimens toward HGF was assessed by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and BrdU (5-bromo-2'-deoxyuridine) assay tests. Calcein AM and ethidium homodimer (EthD-1) fluorescent stains were used to determine the live and dead cells. The morphology and attachment properties of the HGFs were determined via scanning electron microscopy (SEM). Energy dispersive x-ray (EDX) analysis confirmed the presence of AgNPs on the specimens. The MTT test revealed that AgNPs of both sizes and all concentrations presented a decreased cellular metabolic activity compared to the control discs. All concentrations of both sizes of AgNPs affected the cell proliferation rate compared to the control group, as revealed by the BrdU assay. Overall, cytotoxicity of the modified Ti-6Al-4V surfaces depended on cell exposure time. Observation via confocal microscopy confirmed the results of the MTT and BrdU assay tests. Specifically, most cells remained alive throughout the 72-hour culture period. SEM images revealed that adjacent cells form bonds with each other, creating confluent layers of conjugated cells. The findings of the present study indicate that Ti-6Al-4V surfaces modified with 8 nm and 30 nm AgNPs at concentrations of 100 ppm, 200 ppm, and 300 ppm do not produce any serious cytotoxicity toward HGFs. The initial arrest of the HGF proliferation rate recovered at 72 hours. These results on the antibacterial activity against common periodontal pathogens, in combination with the results found in a previous study by the same research group, suggest that AgNP-doped Ti-6Al-4V surfaces are potential candidates for use in implant abutments for preventing peri-implant diseases.

Effect of Tetranychus urticae and Polyphagotarsonemus latus (Acari: Tetranychidae, Tarsonemidae) at different infestation levels and feeding durations on chlorophyll content of bean plants

The study investigated the effects of different initial infestation levels and feeding durations of Tetranychus urticae and Polyphagotarsonemus latus (Acari: Tetranychidae, Tarsonemidae) on the chlorophyll content of the pinto bean plants [Phaseolus vulgaris L. (Fabaceae)]. The experiment was carried out on 3 cm diameter leaf discs and potted plants. To determine the effects of mite feeding on the chlorophyll content of leaf disc, 0 (control), 5, 10, 15, 20, and 25 mated adult females (24-48 hours old) were separately placed on each disc. Chlorophyll measurements were made 5 and 10 days after the initial infestation. For the potted plant bioassay, young plants were infested separately with different densities of P. latus or T. urticae (5, 10, 15, 20, and 25 females per plant) while noninfested plants acted as the control. Data were obtained at intervals of 5 days for a total of 5 times. The chlorophyll contents at infestation levels of 15, 20, and 25 T. urticae per disc were statistically lower than the control discs after exposure for 5 days. The heavily infested discs with 10 or more T. urticae were destroyed until the second measurement. On the other hand, there was no significant difference between the chlorophyll contents of P. latus-infested and noninfested discs 5 days after infestation. However, the content was significantly lower in infested discs at all infestation levels than in noninfested discs 10 days after infestation. According to the potted plant experiment, the chlorophyll contents of T. urticae and P. latus-infested plants were significantly lower than the noninfested plants at all infestation levels from the 10th and 20th days of the infestation, respectively. A highly significant negative correlation was recorded between chlorophyll content and mite density, as well as exposure time indicating that the leaf chlorophyll content of infested bean plants decreased with increasing mite density and time. It was also determined that P. latus required a longer feeding time than T. urticae to affect the chlorophyll content of the bean plants.

Camouflaging endovascular stents with an endothelial coat using CD31 domain 1 and 2 mimetic peptides

ObjectiveImplantation of an endovascular device disrupts the homeostatic CD31:CD31 interactions among quiescent endothelial cells (ECs), platelets, and circulating leukocytes. The aim of this study was to design an endothelial-mimetic coating of nitinol and cobalt-chromium (CoCr) surfaces and stents using synthetic CD31 peptides, to promote device endothelialization and pacific integration within the arterial wall. MethodsPeptides mimicking the domains 1 (D1) and 2 (D2) of CD31 were synthetized and immobilized onto experimental nitinol and CoCr surfaces using a three-step, dip-coating, mussel-inspired protocol using copper-free click chemistry. Human aortic EC phenotype and endothelialization assessment using parallel scratch tests were carried out using five synthetic CD31 peptides coated on 4.8-mm nitinol and CoCr flat disks and were compared with control disks. The CD31 peptide exhibiting the best results in vitro was then immobilized on clinical-grade 3 × 40-mm self-expanding nitinol and 2.5 × 20.0-mm balloon-expandable CoCr stents. Such devices were implanted in native arteries of White New Zealand rabbits, and compared with control uncoated bare metal stents (BMS) and drug-eluting stents 7 and 30 days after implantation using resin cross-sections and scanning electron microscopy (n = 2-3 per group at each time point). ResultsMembrane-distal CD31 D1 and D2 peptides exhibited a distinct capability to foster a healthy endothelial phenotype and to promote endothelialization in vitro. By day 7 after implantation, CD31 nitinol and CoCr stents were evenly covered by wholesome ECs, devoid of thromboinflammatory signs, in contrast with both BMS and drug-eluting stents. Such results were consistent until day 30. ConclusionsMembrane-distal CD31 biomimetic peptides seem to camouflage the device surface effectively, preventing local reactions and promoting rapid and seamless endovascular integration.

Enhancement of adhesion strength and in-vivo evaluation of electrodeposited calcium phosphate/chitosan biocoatings on titanium substrate

Chitosan/calcium phosphate nanocomposites are widely used as a biocompatible coatings for titanium bioimplants in the fields of dentistry and orthopedics to enhance the integration between the implants and the hard bone. However, the poor adhesion strength between the coating and the metal substrate was found to be one of the major problems in the clinical application of these implants. In the current study, we reported the formation of Ca/P coating on titanium (Ti) substrate using electrodeposition. The key factor of the bath ingredients is the change of chitosan's solvent from a commonly used acetic acid to acrylic acid in the electrolyte. The structural analysis including X-ray diffraction (XRD), Raman spectroscopy, and attenuated total reflectance (ATR) confirmed the formation of three phases of Ca/P octacalcium phosphate (OCP), dicalcium phosphate dihydrate (DCPD) brushite, and hydroxyapatite (HA). The bond strength was performed by the tape test (ASTM D3359-09) which showed that nearly 65% of the coatings were removed in the case of using 2, 4, and 6% (v/v) acetic acid as chitosan solvent, while only 5% of the coatings were removed when high concentrations (4 and 6%) of acrylic acid is used in addition to increasing of the surface wettability. Furthermore, the morphology and thickness of the calcium phosphate layer coated on the surface of Ti metal were inspected by scanning electron microscopy (SEM). Finally, an in vivo application was conducted on the optimized coating by surgically placing the coated and control discs into rats’ clavicular bones for 2-weeks healing period. Then biomechanical evaluation was performed to verify the effect of treatment on the interface resistance to shear force, and histological analysis was performed to evaluate the bone tissue reactions to coated discs. The results showed that using acrylic acid instead of acetic acid to dissolve chitosan before in-situ electrodeposition might be an innovative approach to enhance the adhesion strength between chitosan/calcium phosphate-based coatings and titanium metal to be used in orthopedic and dental implant technology.

Effect of bone cement distribution on adjacent disc degeneration after vertebral augmentation for osteoporotic vertebral compression fractures in aging patients.

The influence of vertebral augmentation on adjacent intervertebral discs remains controversial. The purpose of this study is to evaluate the effect of bone cement distribution on adjacent disc degeneration after vertebral augmentation for osteoporotic vertebral compression fractures (OVCFs). Patients with single level OVCF and upper endplate injury who underwent vertebral augmentation were enrolled. The patients were divided into four groups: Group A: bone cement contacted both the cranial and the distal endplates; Group B: bone cement only contacted the cranial endplate; Group C: bone cement only contacted the distal endplate; and Group D: bone cement contacted neither the cranial nor the distal endplates. The cranial discs of the fractured vertebrae were defined as adjacent discs and the upper discs proximally to the adjacent discs were defined as control discs. Degenerative disc change (DDC) was defined as a deteriorated postoperative Pfirrmann score compared with the preoperative score on MR images. The number of DDC cases and the disc heights were analyzed among the groups. A total of 184 patients with an average follow-up time of 28.6 months were included. The number of DDC cases in the adjacent discs was significantly higher than in the control discs in groups A (p < 0.001), B (p = 0.002), and D (p = 0.028), whereas the difference in group C was not statistically significant (p = 0.237). The incidence of adjacent disc degeneration was significantly higher in group A than that in group C (p = 0.06). The adjacent disc heights decreased significantly in groups A, B, and D (p < 0.001, p < 0.001, and p = 0.012, respectively), but did not decrease significantly in group C (p = 0.079). However, no statistical differences were detected among the four groups with respect to the preoperative adjacent disc height, follow-up adjacent disc height, preoperative control disc height, or follow-up control disc height. Bone cement distribution influences adjacent disc degeneration after vertebral augmentation in OVCFs. Cement distribution proximal to the injured endplate can accelerate adjacent disc degeneration, and cement in contact with both the cranial and distal endplates can induce a higher incidence of adjacent disc degeneration.

Cell clusters in intervertebral disc degeneration: an attempted repair mechanism aborted via apoptosis.

Cell clusters are a histological hallmark feature of intervertebral disc degeneration. Clusters arise from cell proliferation, are associated with replicative senescence, and remain metabolically, but their precise role in various stages of disc degeneration remain obscure. The aim of this study was therefore to investigate small, medium, and large size cell-clusters. For this purpose, human disc samples were collected from 55 subjects, aged 37-72 years, 21 patients had disc herniation, 10 had degenerated non-herniated discs, and 9 had degenerative scoliosis with spinal curvature <45°. 15 non-degenerated control discs were from cadavers. Clusters and matrix changes were investigated with histology, immunohistochemistry, and Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Data obtained were analyzed with spearman rank correlation and ANOVA. Results revealed, small and medium-sized clusters were positive for cell proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) in control and slightly degenerated human discs, while large cell clusters were typically more abundant in severely degenerated and herniated discs. Large clusters associated with matrix fissures, proteoglycan loss, matrix metalloproteinase-1 (MMP-1), and Caspase-3. Spatial association findings were reconfirmed with SDS-PAGE that showed presence to these target markers based on its molecular weight. Controls, slightly degenerated discs showed smaller clusters, less proteoglycan loss, MMP-1, and Caspase-3. In conclusion, cell clusters in the early stages of degeneration could be indicative of repair, however sustained loading increases large cell clusters especially around microscopic fissures that accelerates inflammatory catabolism and alters cellular metabolism, thus attempted repair process initiated by cell clusters fails and is aborted at least in part via apoptosis.

Application of organoselenium in inhibiting Candida albicans biofilm adhesion on 3D printed denture base material.

Denture Stomatitis, a chronic mucosal inflammation associated with Candida albicans, is common among denture wearers. Several health conditions have been linked to chronic Candida infections. The complex, multifactorial nature of denture stomatitis requires the continuous pursuit of effective long-term solutions. The present in vitro study investigated the effect of incorporating organoselenium into 3D-printed denture base resin on C. albicans adhesion and biofilm formation. Thirty disks were fabricated using 3D-printed denture base resin and assigned to three experimental groups (10/group): disks without organoselenium (control), disks with 0.5% organoselenium (0.5%SE), and disks with 1% organoselenium (1%SE). Each disk was incubated with approximately 1 × 106 cells/mL of C. albicans for 48 h. Microbial viability (CFU/mL) was quantified by the spread plate method, while Confocal laser scanning microscopy and scanning electron microscope were performed for quantifying the biofilm thickness and examining biofilm morphology, respectively. Data were analyzed using One-way ANOVA with Tukey's multiple comparisons test. CFU/mL was significantly (p<0.05) higher in Control when compared with 0.5%SE and 1%SE, but no significant difference between 0.5%SE and 1%SE. A similar trend was observed with biofilm thickness except that there was no significant difference between the Control and 0.5%SE. There was C. albicans biofilm adhesion on the Control disks, with yeast cells and hyphae formation, whereas on 0.5%SE and 1%SE, there was inhibition of yeast cells transition to hyphae formation. Incorporation of organoselenium into 3D-printed denture base resin was effective in reducing C. albicans biofilm formation and growth on denture base material.

A skinning technique for modeling artistic disk B-spline shapes

Disk B-spline curve provides an alternative shape modeling tool to standard control point based modeling techniques by extending control points to control disks, resulting in an easy and straightforward way of modeling regions or shapes with adjustable thickness. Due to this feature, disk B-spline curves are frequently applied in artistic shape modeling applications, such as brushstroke representation, calligraphy, and animation, but they are also suitable for engineering purposes. However, the boundary curves of the described shapes tend to have unintentional self-intersections or cusps, negatively affecting the usability and artistic value of the resulting shape and texture. In this paper, we introduce an iterative algorithm to give a solution to this problematic issue with the help of an approximating circle skinning method, while preserving the advantageous properties of the disk B-spline curves. Our method also results in smoother texturing of the shape around the more sharply curved sections.

“Are we barking up the wrong tree? Too much emphasis on Cutibacterium acnes and ignoring other pathogens”— a study based on next-generation sequencing of normal and diseased discs

BACKGROUNDThe majority of literature on bacterial flora in the disc stands disadvantaged in utilizing traditional culture methods and targeting a single bacterium, Cutibacterium acnes. PURPOSEOur objective was to document the diversity in the bacterial flora between normal and degenerated discs for shortlisting potential pathogens using next-generation genomic tools. STUDY DESIGNExperimental case-control study. METHODSResearchers employed 16S metagenome sequencing to profile bacterial diversity in magnetic resonance imaging normal healthy discs from brain-dead organ voluntary donors (n=20) and 40 degenerated disc samples harvested during surgery (Modic [MC]=20 and non-Modic [NMC]=20). The V3-V4 region was amplified using universal bacterial primers 341F and 806R, and the libraries were sequenced using Illumina NovoSeq 6000 platform. Statistical significance was set at bacteria with a minimum of 100 operational taxonomic unit (OTU) and present in at least 70% of the samples. The quality check-filtered reads were processed using the QIIME-2 pipeline. The OTU clustering and taxonomic classification were carried out for the merged reads using the Greengenes/SILVA reference database. Validation was done by identification of bacterial metabolites in samples using the liquid chromatography–mass spectrometry approach. RESULTSAbundant bacteria differing widely in diversity, as evidenced by Alfa and Beta diversity analysis, were present in all control and degenerative samples. The number of bacterial genera was 27 (14-gram-positive: 13-gram-negative) in the control group, 23 (10-gram-positive: 11-gram-negative) in the Modic group, and 16 (11-gram-positive: 5-gram-negative) in the non-Modic group. In the Modic group, gram-negative bacteria OTUs were found to be predominant (more than 50% of the total bacteria identified), whereas in control and non-Modic groups the OTUs of gram-positive bacteria were predominant. Species-level analysis revealed an abundance of opportunistic gram-negative pathogens like Pseudomonas aeruginosa, Sphingomonos paucibacillus, and Ochrobactrum quorumnocens in the discs with Modic changes, more than in non-Modic discs. The presence of bacterial metabolites and quorum-sensing molecules like N-decanoyl-L-homoserine lactone, 6-hydroxynicotinic acid, 2-aminoacetophenone, 4-hydroxy-3-polyprenylbenzoate, PE (16:1(9Z)/18:0) and phthalic acid validated the colonization and cell-cell communication of bacteria in disc ruling out contamination theory. Cutibacterium acnes was not the predominant bacteria in any of the three groups of discs and in fact was in the 16th position in the order of abundance in the control discs (0.72%), seventh position in the Modic discs (1.41%), and 12th position (0.53%) in the non-Modic discs. CONCLUSIONThis study identified a predominance of gram-negative bacteria in degenerated discs and highlights that Cutibacterium acnes may not be the only degeneration-causing bacteria. This may be attributed to the environment, diet, and lifestyle habits of the sample population. Though the study does not reveal the exact pathogen, it may pave the way for future studies on the subject. CLINICAL SIGNIFICANCEThese findings invite further investigation into causal relationships of bacterial profile with disc degeneration phenotypes as well as phenotype-driven clinical treatment protocols.

An experimental study on icephobicity and hydrophobicity of concrete surface with Dual crystallization Engineered topical treatment

Ice when formed on structural materials exhibits strong bonds, which poses a major challenge to many industries. To remove the ice, the creation of hydrophobic surfaces is used as a passive ice removal technique by reducing ice adhesion. Concrete surfaces treated by Pavix Dual Crystallization Engineered (DCE) material show strong water-repelling characteristics. However, the effect of such treatment on ice adhesion is yet to be studied. To quantify this effect, a series of direct shear tests were performed on concrete specimens with the top surface treated with a Pavix DCE material. TxDOT standard Class S concrete was used as control concrete and mixed at two water-cement ratios, 0.45 and 0.43. Ice-adhesion shear tests were performed on control and DCE-treated concrete disks using a customized direct shear test device at two controlled sub-freezing temperatures, −1 °C and −10 °C. In addition, water-repellent properties and contact angle were measured using a tensiometer under static and receding conditions. Results show reductions of more than 83% in ice adhesion of ice adhesion and more than 98-degree contact angles for DCE-treated concrete specimens. The measured results quantify the anti-icing benefit of DCE treatment and provide insights into understanding the anti-icing mechanism of the treated concrete.

Effect of Antibacterial Agents on Dentin Bond Strength of Bioactive Restorative Materials.

Treating dentin surfaces with antibacterial agents prior to bonding bioactive restorations might affect their mechanical properties. In this study, we evaluated the effect of silver diamine fluoride (SDF) and chlorhexidine (CHX) on the shear bond strength (SBS) of bioactive restorative materials. Dentin discs were treated with SDF for 60 s or CHX for 20 s and bonded with four restorative materials, namely Activa Bioactive Restorative (AB), Beautifil II (BF), Fuji II LC (FJ), and Surefil One (SO). Control discs were bonded without treatment (n = 10). SBS was determined using a universal testing machine, and a scanning electron microscope (SEM) was used for the evaluation of the failure mode and the cross-sectional examination of adhesive interfaces. The SBS of each material between different treatments and of the different materials within each treatment were compared via a Kruskal-Wallis test. The SBS of AB and BF was significantly higher than that of FJ and SO in the control and CHX groups (p < 0.01). In the latter, SBS was higher in FJ than SO (p < 0.01). SO had a higher value with SDF compared to CHX (p = 0.01). The SBS of SDF-treated FJ was higher than that of the control (p < 0.01). SEM showed a more homogenous and improved interface of FJ and SO with SDF. Neither CHX nor SDF compromised the dentin bonding of bioactive restorative materials.

Analysis of the process of qualifying the welding technology of S355JR structural steel using the submerged arc welding method

This paper presents the issue of welding technology qualification using the example of structural steel S355JR with a plate thickness of 25 mm and 100 mm, bevelling V. The main objective of this work was to attempt to perform a full qualification of the submerged arc welding process in accordance with the requirements of PN EN ISO 15614. Particular attention was paid to the issue of the qualification of welding technology. The samples were subjected to non-destructive testing, i.e. visual and penetrant testing, as well as ultrasonic testing and heat treatment. This was followed by destructive testing, including macroscopic testing and hardness testing. According to the proposed procedure for the recognition of submerged arc welding technology, once the necessary tests had been carried out and the protocols with positive results had been obtained. The documentation had been completed, the analysis needed to obtain certificates of conformity for factory production control and welding quality was carried out.Submerged arc welding is often used for highly responsible butt joints, particularly when joining thick components. This has been achieved through the proper design of the preparation of the parts to be welded and the development of a welding technology that practically eliminates the pre-phase that occurs in traditional technology, thereby eliminating the risk of it affecting the quality of the welded joint.During the implementation of submerged arc welding, a number of technological problems were encountered. The first test joints contained many defects, i.e. sticking and slag inclusions inside the welds. In addition, obtaining welds with the correct profile and removing the slag from the weld groove was difficult. These obstacles were eliminated experimentally by carrying out successive tests using different parameters and welding groove geometries.The correct implementation of any welding process depends on its input parameters. These parameters include welding current, welding speed, welding current, wire diameter, welding voltage and many others. Submerged arc welding (SAW) is widely used in the industry for manufacturing as it is more reliable, provides deep penetration in the work, ensures a smooth finish on objects, and results in high productivity.The technology was developed for a company that manufactures control discs for steam turbines.

Effects of Hypochlorous Acid and Hydrogen Peroxide Treatment on Bacterial Disinfection Treatments in Implantoplasty Procedures.

One of the main problems in oral implantology today is peri-implantitis, which affects almost 20% of dental implants placed in patients. One of the most commonly used techniques to eliminate bacterial biofilm is the implantoplasty, that consists of the mechanical modification of the implant surface topography followed by treatments with chemical reagents for decontamination. In this study, the main aim is to evaluate the use of two different chemical treatments based on hypochlorous acid (HClO) and hydrogen peroxide (H2O2). For this purpose, 75 titanium grade 3 discs were treated with implantoplasty according to established protocols. Twenty-five discs were used as controls, 25 were treated with concentrated HClO and 25 were treated with concentrated HClO followed by treatment with 6% H2O2. The roughness of the discs was determined using the interferometric process. Cytotoxicity with SaOs-2 osteoblastic cells was quantified at 24 and 72 h, whereas bacteria proliferation using S. gordonii and S. oralis bacteria was quantified at 5 s and 1 min of treatment. The results showed an increase in the roughness values, the control discs had an Ra of 0.33 μm and those treated with HClO and H2O2 reached 0.68 μm. Cytotoxicity was present at 72 h, together with a significant proliferation of bacteria. These biological and microbiological results can be attributed to the roughness produced by the chemical agents that triggered bacterial adsorption while inhibiting osteoblast adhesion. The results indicate that even if this treatment can decontaminate the titanium surface after implantation, the produced topography will generate an environment that will not favor long-term performance.

Nucleus Pulposus Cells from Calcified Discs Promote the Degradation of the Extracellular Matrix through Upregulation of the GATA3 Expression.

Disc calcification is strongly associated with disc degeneration; however, the underlying mechanisms driving its pathogenesis are poorly understood. This study aimed to provide a gene expression profile of nucleus pulposus cells (NPCs) from calcified discs, and clarify the potential mechanism in disc degeneration. Primary NPCs were isolated from calcified and control discs (CAL-NPC and CON-NPC), respectively. The proliferation and extracellular matrix (ECM) metabolism capacities of the cells were evaluated using MTT and Western blotting, respectively. RNA sequencing was used to identify differentially expressed genes (DEGs) in the CAL-NPCs. The biological functions of the DEGs were analyzed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. The transcription factor database and Cytoscape software were used to construct the transcription factor-DEGs regulatory network. The role of the verified transcription factor in NPC proliferation and ECM metabolism was also investigated. The CAL-NPCs exhibited a lower proliferation rate and higher ECM degradation capacity than the CON-NPCs. In total, 375 DEGs were identified in the CAL-NPCs. The GO and KEGG analyses showed that the DEGs were primarily involved in the regulation of ribonuclease activity and NF-kappa B and p53 signaling pathways. GATA-binding protein 3 (GATA3) with the highest verified levels was selected for further studies. Overexpression of GATA3 in the CON-NPCs significantly inhibited their proliferation and promoted their ECM degradation function, while the knockdown of GATA3 in the CAL-NPCs resulted in the opposite phenotypes. This study provided a comprehensive gene expression profile of the NPCs from the calcified discs and supported that GATA3 could be a potential target for reversing calcification-associated disc degeneration.

Efficacy of Denture Cleansers on Microbial Adherence and Surface Topography of Conventional and CAD/CAM-Processed Denture Base Resins.

This study assessed the efficacy of five denture cleansers on the microbial adherence and surface topography of conventional and CAD/CAM denture base resins. Acrylic resin discs were fabricated using conventional, milling, and 3D printing methods (N = 180). The discs were contaminated with dual species of Candida albicans and Streptococcus mutans biofilm for 72 h and then disinfected with either of the denture cleansers (Fittydent cleansing tablets, 2% Chlorhexidine gluconate, 0.2% Chlorhexidine gluconate, 0.5% sodium hypochlorite, and 1% sodium hypochlorite (n = 10). Distilled water served as the control group. The colony-forming units of the microorganisms were calculated, followed by post-treatment surface roughness. Data were statistically analyzed using one-way ANOVA, paired t-test, and post hoc Tukey HSD test (α = 0.05). Among the denture cleansers, 2% Chlorhexidine gluconate, 0.5% sodium hypochlorite, and 1% sodium hypochlorite had the best cleansing effect on the resin discs and demonstrated zero growth of colonies for both the species. Comparing the material groups, the 3D-processed discs showed higher colony-forming units followed by the conventional and CAD/CAM milled group. The highest surface roughness was demonstrated by the 3D-printed discs (0.690 ± 0.08 μm), followed by the conventional (0.493 ± 0.11 μm) and the milled groups (0.301 ± 0.08 μm). The tested chemical denture cleansers affected the Candida albicans and Streptococcus mutans adhesion compared to control discs immersed in distilled water. The clinician may recommend to their patient to use 2% chlorhexidine gluconate for the disinfection of CAD/CAM PMMA denture base materials.

The role of endplate injury in intervertebral disc degeneration after vertebral augmentation in OVCF patients.

Whether vertebral augmentation can induce or aggravate the degeneration of adjacent intervertebral discs remains controversial. The purpose of this study is to explore the role of endplate injury in intervertebral disc degeneration after vertebral augmentation. The imaging data of patients with single-segment osteoporotic vertebral compression fractures (OVCFs) were retrospectively analyzed. The upper and lower discs of the fractured vertebrae were defined as cranial and caudal discs, and the discs adjacent to the cranial discs were defined as control discs. According to the integrity of the cranial and caudal endplates, they were divided into an injury group and a noninjury group. At follow-up, the increase in the modified Pfirrmann score on MRI compared with the baseline grade was defined as the occurrence of a degenerative disc change (DDC). The changes in the disc height and the number of DDC cases on MRI during the follow-up in each group were analyzed. A total of 56 patients with OVCFs were included in this study, with an average follow-up time of 18.8 ± 14.1 months (3-62 months). In the cranial and caudal discs, the number of DDC cases in the endplate injury group was significantly higher than that in the noninjury group (P = 0.007 and P = 0.018). However, the number of DDC cases in the whole endplate injury group (including the cranial and caudal endplates) was significantly higher than that of the whole noninjury group (P = 0.000) and the control group (P = 0.000). The number of DDC cases in the whole noninjury group was not different from that of the control group (P = 0.192). At follow-up, the disc height of the cranial and caudal endplate injury group was significantly lower than the baseline (P = 0.000 and P = 0.001), but the disc height of the noninjury group was not significantly lower than the baseline (P = 0.074 and P = 0.082). Endplate injury is associated with adjacent intervertebral disc degeneration in OVCF patients after vertebral augmentation. Evaluation of endplate damage before vertebral enhancement in OVCF patients has an important reference value for predicting the outcome of adjacent intervertebral discs after surgery.