Evaluation of clinical performance of additively manufactured and milled polyetheretherketone (PEEK) inlays compared with indirect composite resin inlays over a one-year follow-up: A randomized clinical trial.

STATEMENT OF PROBLEM: Data on polymer materials, particularly polyetheretherketone (PEEK) used in restorative dentistry, are scarce, as is knowledge concerning the clinical efficacy of PEEK restorations produced through additive manufacturing when compared with existing indirect materials and techniques. PURPOSE: The purpose of this randomized clinical trial was to evaluate the clinical performance of additively manufactured and milled PEEK inlays compared with composite resin inlays according to modified United State Public Health Service (USPHS) criteria over a 1-year follow- up. MATERIAL AND METHODS: Participants were allocated into 3 distinct categories based on the materials and techniques used: R1 denoting teeth restored with 3 dimensionally (3D) printed PEEK inlays (N=16), R2 representing teeth restored with milled PEEK inlays (N=16), and R3 indicating the comparator group comprising teeth restored with milled composite resin inlays (N=16). After the placement of inlay restorations, evaluations were conducted at 3 time points (T): baseline (T0), 6 months (T1), and 12 months (T2) by using the modified USPHS criteria for assessing anatomic form, color match, marginal discoloration, marginal adaptation, surface texture, secondary caries, retention, and postoperative sensitivity. Ordinal data were analyzed using the Kruskal-Wallis test, followed by the Dunn post hoc test for between group comparisons, as well as the Friedman test, followed by the Nemenyi post hoc test for within group comparisons (α=.05). RESULTS: Across all parameters and intervals, most of the restorations within each group exhibited an alfa score, with no statistically significant differences noted (P>.05). However, concerning color match, all restorations within the PEEK groups received a bravo score, indicating a statistically significant difference in intergroup comparison between the milled composite resin groups and the PEEK group (P<.001). However, no significant variances were noted in the scores evaluated across different follow-up periods (P>.05). CONCLUSIONS: Subtractive and additive manufacturing techniques, as well as PEEK and composite resin materials together, offer clinically acceptable functioning restorations over 1 year. PEEK material can be used as a suitable alternative to commonly used indirect composite resin intracoronal restorations in posterior areas. Improvements in terms of surface texture and esthetics are required.

Global and regional cardiac magnetic resonance feature tracking left ventricular strain analysis in assessing early myocardial disease in ß thalassemia major patients.

BACKGROUND: Cardiac magnetic resonance imaging (CMR) is the modality of choice for quantification of myocardial iron overload in ß-thalassemia major patients using the T2* sequence. CMR feature tracking (FT) is a recent magnetic resonance imaging tool that gives an idea about myocardial fibers deformation; thus, it can detect early impairment in myocardial function even before the reduction in ejection fraction. METHODS: This study aims to assess the ability of left ventricular CMR-FT in the early detection of systolic dysfunction in ß thalassemia major patients and to correlate it with the degree of myocardial iron overload measured by CMR T2*. This prospective study enrolled 57 ß thalassemia major patients who received long-term blood transfusion and 20 healthy controls. CMR was used to evaluate left ventricular volumes, ejection fraction, and the amount of myocardial T2*. A two-dimensional left ventricular FT analysis was performed. Both global and segmental left ventricular strain values were obtained. RESULTS: The mean global circumferential strain (GCS) and global radial strain (GRS) values were significantly lower in patients compared to control (P = 0.002 and P = 0.006, respectively). No correlation was found between T2* values and ejection fraction; however, there was a significant correlation between T2* values and GCS and GRS (P = 0.012 and P = 0.025, respectively) in thalassemia patients. Regional strain revealed significantly lower values of GCS and GRS in basal regions compared to apical ones (P = 0.000). CONCLUSIONS: Our study revealed that CMR-FT can play a role in the early detection of systolic impairment in thalassemia patients.

Microplastics in aquatic ecosystems of Africa: A comprehensive review and meta-analysis.

Microplastic pollution is a global issue of great public concern. Africa is flagged to host some of the most polluted water bodies globally, but there is no enough information on the extent of microplastic contamination and the potential risks of microplastic pollution in African aquatic ecosystems. This meta-analysis has integrated data from published articles about microplastic pollution in African aquatic ecosystems. The data on the microplastic distribution and morphological characteristics in water, sediments and biota from African rivers, lakes, oceans and seas were extracted from 75 selected studies. Multivariate statistics were used to critically analyze the effects of sampling and detection methods, ecological risks, spatial distribution and similarity of microplastics in relation to the geographical distance between sampling sites. This study found that sampling methods have significant effect on abundance and morphological characteristics of microplastics and that African aquatic ecosystems are highly contaminated with microplastics compared to global data. The most prevalent colors were white, transparent and black, the most prevalent shapes were fibres and fragments, and the most available polymers were polypropylene (PP), polystyrene (PS) and polyethene terephthalate (PET). Microplastic polymers similarity decreased with an increase in geographical distance between sites. Risk levels of microplastics in African aquatic ecosystems were comparatively high, and more than 40 % of water and sediments showed highest level of ecological risk. This review provides recent information on the prevalence, distribution and risks of microplastics in African aquatic ecosystems.

Evaluation of antimicrobial and antioxidant activity of zinc oxide nanoparticles biosynthesized with Ziziphus spina-christi leaf extracts.

Background: Due to their simplicity, eco-friendliness, availability and non-toxicity, the greener fabrication of metal and metal oxide nanoparticles has been a highly attractive research area over the last decade. Aim: This study aimed to assess the antioxidant and antimicrobial activities of the green synthesized zinc oxide nanoparticles (ZnO-NPs) using an aqueous leaf extract of Ziziphus spina-christi. Method: The antioxidant property of ZnO-NPs was analyzed by the α, α-diphenyl-ß-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2). Additionally, the diffusion agar method assessed the antimicrobial activities against bacteria and fungi. Results: ZnO-NPs synthesized by Z. spina-christi had shown promising H2O2 and DPPH free radical scavenging actions compared to vitamin C. The ZnO-NPs exhibited significant antibacterial activity against the tested bacteria with various susceptibility as a concentration-dependent effect. The largest zone of inhibition for Staphylococcus aureus (S. aureus) was observed (36 ± 2 mm) compared to Escherichia coli (E. coli) (15 ± 2 mm) by the same concentration of ZnO-NPs. The ZnO-NPs showed remarkable antifungal activity against Aspergillus niger. Conclusion: It can be concluded that, ZnO-NP have been imposed as suitable antimicrobial agent being able to combat both S. aureus and E. coli in vitro.

Right Ventricular Strain Analysis By Tissue Tracking Cardiac Magnetic Resonance Imaging In Pediatric Patients With End-Stage Renal Disease.

PURPOSE: To investigate right ventricular (RV) volume and mass by cardiac magnetic resonance (CMR) and the added value of tissue tracking strain analysis as markers of RV dysfunction in pediatric patients with end-stage renal disease (ESRD) and preserved RV ejection fraction. MATERIALS AND METHODS: Twenty-five children with ESRD and preserved RVEF (>50%) and 10 healthy control children were enrolled. Tissue tracking CMR was used to assess Global Longitudinal, circumferential (GCS), and radial short and long axes (GRS SAX and GRS LAX) RV strains in the patients group compared with controls. Correlations between strain parameters and other CMR parameters and clinical biomarkers were assessed. Binary logistic regression was used to test the independence of cofounders and detect their significance. RESULTS: RV end-diastolic volume and mass (RVMi) were significantly higher in patients (97.2±19.3 mL/m 2 and 26.6±7gr/m 2 ) than control (71±7.8 mL/m 2 and 11.9±2 gr/m 2 , P values 0.000). All RV global strain parameters were significantly impaired in patients compared with control (all P values <0.05). RV Global Longitudinal was significantly correlated to LVEF (r=-0.416, P =0.039), LVEDVi (r=0.481, P =0.015), LVMi (r=0.562, P =0.004), and systolic blood pressure index (r=0.586, P =0.002). RV GRS (LAX) was significantly correlated to LV GCS (r=-0.462, P =0.020) and LV GRS (SAX) (r=0.454, P =0.023). GRS (SAX) and GCS demonstrated the highest diagnostic accuracy (area under curve: 0.82 and 0.81) to detect strain impairment. Univariate binary logistic regression with patients versus control as dependent variables identified LVMi, RV end-diastolic volume, RVMi, weight, body surface area, RV GCS, RV GRS (LAX), RV GRS (SAX), LV GCS, and LV GRS (SAX) as significantly correlated to patients with ESRD. When adjusted to other cofounders in the multivariable model, only RVMi remained as an independent significant cofounder (Odds ratio:0.395, P =0.046). CONCLUSION: RV global strain, volume, and mass by CMR are markers of RV dysfunction in ESRD pediatric patients with preserved RVEF.

Large fusiform aneurysm of the superior vena cava: CT findings.

A 62-year-old man presented complaining of atrial fibrillation. Plain chest radiography and contrast-enhanced computed tomography (CT) revealed a large fusiform aneurysmal dilatation of the upper segment of the superior vena cava (SVC) without evidence of rupture, thrombosis, or pulmonary embolism. It was decided to treat the patient conservatively with follow-up imaging recommended.