Manufacturer's Recommendations Research Articles

In Vitro Biomechanics of Attachment Use and Their Placement for Extrusive Tooth Movement by Aligner Mechanotherapy.

The objective of the presented study was to evaluate the biomechanics of aligners utilising attachments and the effect of their placement for extrusion. An invitro Orthodontic SIMulator (OSIM) was used to measure forces and moments produced through aligners incorporating attachments. The maxillary teeth on OSIM were digitally scanned to generate an STL model that was modified by placing a rectangular shaped attachment. Four models were designed with variation in attachment placement: Model NA-no attachment; model BA-buccal attachment; model LA-lingual attachment; model BL-both buccal and lingual attachments. Aligners (n = 30/model) were fabricated using a 0.75 mm thick polyethylene terephthalate material using a Biostar machine following the manufacturer's recommendations. A one-way MANOVA, followed by one-way ANOVA was used to test the effect of models on occlusogingival force (Fz) and mesiodistal moment (Mx) at 0.20 mm of gingival displacement of the left lateral incisor. The BL model exerted maximum Fz (1.22 ± 0.20 N), followed by models BA (1.18 ± 0.25 N) and LA (1.07 ± 0.19 N). The model NA exerted a negligible Fz (0.14 ± 0.08 N) that was statistically different from all other models. The models BA and LA generated Mx that has the tendency to tip the crown of tooth lingually (10.00 ± 3.12 Nmm) and buccally (-1.29 ± 2.26 Nmm), respectively. The models show statistically significant differences between models BL, BA and LA. There was no statistically significant difference between models BL and NA. The experimental evidence suggest that attachments on the lateral incisor could improve the predictability of extrusion forces applied with aligners. The models BL and LA provided favourable biomechanics by generating clinically significant extrusion forces without significant tipping of the lateral incisor tooth.

Potential of Acacia Extract as a Collagen Crosslinker and Stabilizer of the Resin-dentin Interface.

The aim of this study was to investigate whether different concentrations of acacia extract could improve the biological stability of dentin collagen. Slice (n=3) and beam (n=5) samples of dentin obtained from human third molars were demineralized and treated with the following solutions: G1 (control)-deionized water; G2-1% acacia extract; G3-2% acacia extract; and G4-3% acacia extract. The dentin slices were analyzed by Fourier transform infrared (FTIR) spectrophotometry to observe their interactions with collagen. The beams were submitted to digestion with type I bacterial collagenase solution, and the percentage of weight was calculated to evaluate the resistance to enzymatic biodegradation. The Adper Scotchbond Multipurpose adhesive system was applied on the flat dentin surfaces according to the manufacturer's recommendations (G1). In groups G2, G3 and G4, acacia extract at concentrations of 1%, 2%, and 3%, respectively, were applied after acid etching. A resin composite block was built on the adhesive, and the teeth were cut to obtain beams (n=7 teeth; ~12 beams per tooth) with cross-sectional areas of approximately 0.8 mm2. Half of the specimens were submitted to the microtensile bond strength (µTBS) test in a universal testing machine at a crosshead speed of 0.5 mm/min, and the other half were submitted to the µTBS test after six months of storage in distilled water. FTIR analysis showed the interactions of the three concentrations of acacia extract with collagen. According to ANOVA and Tukey tests, G1 had the highest biodegradation rate (100%), which was significantly higher than the rates of G2 (24%), G3 (23%) and G4 (17%) (p<0.05). According to two-way ANOVA and Tukey tests, only G1 showed a significant decrease in µTBS after six months of storage (p<0.05). It was concluded that 1%, 2%, and 3% acacia extract all interacted with human dentin collagen, reduced collagen biodegradation and favored the stabilization of the bonding interface at the six-month evaluation.

Quality comparison of autotransfusion devices in cardiac surgery: a prospective observational cohort study.

We sought to conduct a quality improvement initiative to compare the wash quality and speed of autologous red blood cell (RBC) processing of four autotransfusion devices during cardiac surgery. Using a prospective observational cohort study approach, we prospectively evaluated four commercially available autologous cell savage devices (autoLog IQ™, Medtronic plc, Minneapolis, MN, USA [135mL]; Xtra™, LivaNova, plc, Houston, TX, USA [125mL, 225mL]; Cell Saver® Elite®+, Haemonetics Corp., Boston, MA, USA [125mL, 225mL]; and CATSmart®, Fresenius Kabi AG, Bad Homburg vor der Höhe, Germany) in adult patients undergoing cardiac surgery. Device settings were determined by manufacturer recommendations for optimal wash quality. We collected pre- and postprocessing samples, volumes, and processing times from each device to calculate removal ratios of heparin, potassium, plasma free hemoglobin (PfHb), white blood cells (WBCs), platelets, reinfusion concentrations of heparin and potassium, and red blood cell (RBC) recovery rates. A total of 130 consecutive patients underwent autologous cell salvage, but 15 cases were excluded because of incomplete data. All devices removed > 99% heparin, > 95% potassium, > 94% platelets, and > 85% PfHb from collected shed blood. Comparison of processing sets showed significant differences in median [interquartile range] WBC removal ratios, ranging from 26 [19-33]% to 59 [42-68]%, and median heparin reinfusion concentrations, which ranged from 0.09 [0.08-0.11] to 0.63 [0.55-0.70] U·mL-1 processed red cells. Median RBC recovery rates also showed significant differences between processing sets, ranging from 8 [8-10] mL RBC·min-1 to 24 [22-25] mL RBC·min-1. Wash quality and processing speed differed between autotransfusion devices and processing sets. These findings may have clinical implications when large volumes of shed blood are processed and reinfused.

Analysing Consumer Perspectives and Charging Forward On Green Electric Vehicles

The rapid advancement and broad adoption of electric vehicles (EVs) represent a significant transformation within the electric vehicle industry, driven by the increasing demand for environmentally friendly and sustainable transportation options. This study aims to analyse consumer perceptions of EVs, identifying key factors that influence their attitudes and decision-making processes. The research explores various dimensions, including environmental consciousness, economic considerations, technological advancements, and infrastructural readiness, that impact consumer acceptance of EVs. Additionally, it addresses the primary barriers to EV adoption, such as cost concerns, range anxiety, and inadequate charging infrastructure. By understanding these perceptions and challenges, the study provides strategic recommendations for policymakers, manufacturers, and marketers to foster greater acceptance and adoption of EVs. In the end, this study aims to help create successful plans that will propel the shift towards a greener electric vehicle in future.

Prevalence and Antimicrobial Susceptibility of Mycoplasma hominis and Ureaplasma Species among Women in Dakar

Introduction: Genital mycoplasmas, which cause infections of the lower reproductive tract in women, are a major cause of morbidity and complications. The aim of this study was to determine the prevalence of mycoplasma infections and the antibiotic susceptibility profile among women in Dakar. Material and methods: We conducted a retrospective descriptive study over a four-year period, from 02 January 2018 to 31 December 2021. The study population consisted of women referred to the microbiology laboratory at Military Hospital of Ouakam for genital mycoplasma testing. The Mycoplasma IES kit was used for mycoplasma testing and susceptibility testing in accordance with the manufacturer's recommendations. Results: A total of 1431 patients were enrolled during the study period. The mean age was 32.6 ± 8.5 years. The overall prevalence of mycoplasma infection was 55.8% (798/1431). Of the 798 positive cultures, 52.8% were infected with Ureaplasma urealyticum (UU) and 17.9% with Mycoplasma hominis (MH). UU+MH co-infection was 31.08%. Analysis of the sensitivity profiles showed that UU was sensitive to most of the antibiotics used, while M. hominis strains showed low levels of resistance to tetracyclines (TET DOX, MIN), quinolones (OFX, LEV, SPA) and JOS. This resistance was much higher with macrolides (ERY, ROX, AZT), certain quinolones (ASP, CIP) and aminoglycosides (SPE). However, M. hominis strains were much more resistant to these molecules than U. urealitycum isolates. Conclusion: Our study revealed a high rate of genital mycoplasma infection among women in Dakar. The high rates of resistance to certain molecules underline the importance of surveillance to prevent transmission of resistant strains and rational use of antibiotics.

Lube oil life prediction for heavy earth moving machinery (HEMM): A machine learning approach

Evaluating lubricant life is crucial for maintaining equipment reliability and preventing failures. Conventional methods often depend on original equipment manufacturer recommendations for lubricant changes, which may result in the premature disposal of operationally effective lubricants, leading to economic costs and degrading overall efficiency. The chemical properties of these samples are evaluated by calculating multiple parameters such as total acid number, total base number, oxidation index, soot level, and water contamination. In addition, rheological properties through viscosity index analysis and the tribological properties via friction-wear analysis are determined. In this study, an artificial neural network (ANN) (a four-layer perceptron) and an adaptive neuro-fuzzy inference system (ANFIS) are applied to predict oil conditions based on multiple calculated parameters. Performance and comparison of these advanced mathematical models are evaluated using statistical indices. Overall, the artificial intelligence (AI)-powered approach proved effective in predicting lubricant life for HEMM. Among the AI models, the ANN model demonstrated particularly strong performance, with a correlation coefficient of 0.99 compared to 0.98 for the ANFIS model. Implementing the ANN model could lead to a potential 19% reduction in current engine oil expenses, which would lower operating costs and decrease environmental impact by reducing the frequency of oil disposal.

Accuracy of Automated External Defibrillator Pad Placement During Out-of-Hospital Cardiac Arrest Resuscitation Simulations.

Out-of-hospital cardiac arrest (OHCA) victims receiving defibrillation from an automated external defibrillator (AED) placed early in the chain of survival are more likely to survive. We sought to explore the accuracy of AED pad placement for lay rescuers (LR) and first responders (FR). We conducted a secondary analysis of data collected during randomized OHCA simulation trials involving LRs and FRs. The LRs received hands-only CPR and AED guidance from a simulated 9-1-1 telecommunicator. The FRs did not receive telecommunicator instruction. Participants were surveyed about medical training and experience. Correct AED pad placements (anterior: AP, lateral: LP) were individually determined from video abstraction based on manufacturer's recommendations and distance to anatomical landmarks. Incorrect AP placement was defined as the upper edge of the pad past the crest of the trapezius, the medial edge past midline, or the lower edge beyond the nipple line. Incorrect LP placement was defined as the upper edge of the pad past the nipple line, the medial edge past midline, or the lower edge beyond the navel line. We examined the association between correct pad placement and previous CPR training (current, expired, or never) for LR and correct pad placement and self-reported recent field experience (<1 year) with AED application for FR using Fisher's exact. Lay rescuers correctly placed the AP in 30/38 (78.9%) and the LP 30/38 (78.9%) simulations. Application did not differ significantly based on previous CPR training (AP p = .236, LP p = .621). The most common incorrect placement was too low for both AP (5/8, 62.5%) and LP (4/8, 50.0%). First responders applied the AP correctly in 16/18 (88.9%) and the LP in 14/18 (77.8%) simulations. Among FRs, correct pad application did not differ significantly based on recent field experience (AP p = .497, LP p = .119). The most common incorrect placement was too low for both AP (2/2, 100.0%) and LP (3/4, 75.0%). There is an opportunity for improvement for both LRs and FRs to apply AEDs per manufacturer's recommendations. Further research is needed to improve instructions and follow-up training to ensure accurate AED pad placement.

Classifying crash causation patterns in 2-vehicle collisions between autonomous and conventional vehicles.

This study aims to investigate the causes of 2-vehicle collisions involving an autonomous vehicle (AV) and a conventional vehicle (CV). Prior research has primarily focused on the causes of crashes from the perspective of AVs, often neglecting the interactions with CVs. To address this limitation, the study proposes a classification framework for crash causation patterns in 2-vehicle collisions involving an AV and a CV, considering their interactions. The framework categorizes the crash causation patterns into 5 distinct types: (1) failure of the AV system, (2) failure of takeover control, (3) driver error after takeover, (4) CV failure to adapt to unforeseen changes in AV behaviors, and (5) other factors related to the CV. Utilizing the AV crash data set proposed by Zheng etal., this study extracted 450 two-vehicle collisions involving AVs and CVs for our analysis. Our analysis reveals that the majority of 2-vehicle collisions are triggered by CVs, specifically identified in patterns 4 and 5. Pattern 4 is the primary crash causation factor, accounting for 55% of total collisions. The leading contributing factor to pattern 4 is the improper response of CVs to AVs stopping. There are notable variations in crash injury severity, collision type, and environmental conditions across different causation patterns. Crashes stemming from human drivers' errors (patterns 3, 4, and 5) are more likely to result in moderate to severe injuries. Specifically, pattern 4 notably exhibits the highest likelihood of causing rear-end collisions, whereas patterns 1 and 5 are more prone to causing side collisions. Additionally, crashes associated with pattern 4 are more frequently observed in locations with traffic controls or obstacles. Based on our findings, we propose several recommendations for manufacturers to enhance AV safety performance. These include minimizing planning errors in autonomous driving algorithms, improving communication abilities between AVs and other road users for smoother interactions and better anticipation of actions, and providing specialized driver training for navigating mixed environments with both AVs and CVs.

Assessment of transpulmonary thermodilution, ultrasound dilution, and esophageal Doppler against direct pulmonary artery flow for cardiac output monitoring in anesthetized cats.

To assess the agreement of transpulmonary thermodilution (TPTD) and transpulmonary ultrasound dilution (TPUD) against direct measurement of main pulmonary artery flow with an ultrasound transit time flow probe (UTF) over a wide range of conditions in anesthetized cats. Additionally, the trending ability of TPTD, TPUD, and esophageal Doppler ultrasonography (EDU) was evaluated against UTF. 12 purpose-bred cats were used. One cat was used for a pilot study. The cats were instrumented according to the manufacturer's recommendation. Paired measurements were made over a wide range of cardiac output. Agreement was analyzed with Bland-Altman analysis with repeated measures, and trending ability was assessed by 4-quadrant plot and concordance rate. Interchangeable was defined as percentage error less than simplified total error. Acceptable trending was defined as concordance rate > 95%. Bias and percentage error were -0.084 L·min-1 and 38.2% for TPTD and -0.041 L·min-1 and 52.9% for TPUD. The concordance rate was 100%, 95.5%, and 64% to 65% for TPTD, TPUD, and EDU, respectively. Both TPTD and TPUD were not interchangeable to UTF. Both TPTD and TPUD provided acceptable trending ability but not EDU. Transpulmonary thermodilution and TPUD allow detection of the direction of cardiac output changes in anesthetized cats but not EDU. Clinical and research use of these 3 devices warrants careful consideration of the limitations presented in this study.

Influence of macrogeometry on primary stability and insertion torque in dental implants.

Introduction: The primary stability and insertion torque of osseintegrated implants is fundamental to the success of osseointegration, especially in cases where a prosthesis with immediate load is installed. Objetive: This study aimed to assess the influence of the macrogeometry of two implant types on insertion torque and primary stability. Materials and Methods: This study utilized 40 implants, comprising 20 conical and 20 cylindrical, divided into four experimental groups. These implants were installed by a single operator, in a synthetic bone block following the manufacturer's recommendations and the sub-instrumentation technique. Implant stability was immediately assessed post-installation using magnetic resonance frequency analysis, measured by Osstellâ. The insertion torque was determined using a surgical implant installation motor. The resulting data were subjected to statistical analysis using the Kruskal–Wallis test, with Dunn's post hoc test employed to determine any significant differences between the implant groups in terms of insertion torque and primary stability. Results: A significant difference was observed in the stability of buccolingual (p=0.002) and the average stability (p=0.008), with respective effect sizes of 0.197 and 0.335. The insertion torque also demonstrated significance (p=0.018). Notably, a decrease in the values of the 04×10 implants was observed when compared to the 3.5×10 implants. Conclusions: Implants with a smaller diameter exhibited greater primary stability, whereas those with a larger diameter demonstrated higher insertion torque values. Keywords: Dental implant; primary stability; insertion torque.

Preventive service interval extension on Caterpillar 789 and 793 off-highway trucks

Objective: The project aims to develop and implement contamination control measures to extend the service intervals of Caterpillar 789 and 793 trucks. This will reduce operating costs by extending oil change intervals, maintaining oil quality throughout the lifespan of components and systems. Methodology: The feasibility of Caterpillar's "Committed to Customer Success" program was analyzed in collaboration with TRACSA. The project included simulating results to evaluate the impact of extending service intervals on reducing lubricant consumption, establishing machinery affinities, purchase volumes, suppliers, and maintenance schedules according to the manufacturer's recommendations. Results: The simulation showed significant savings in lubricant use, achieving a 50% cost reduction. Other benefits included prolonging the lifespan of components, better cleaning conditions, reduced handling of used oil, reduced carbon footprint, increased machine availability, and reduced downtime, improving work efficiency and safety.

A Comparison of the Accuracy of Two Non-dental 3D Printers and a Standard Dental 3D Printer for Printing Dental Models: An In Vitro 3D Analysis.

While the majority of dentists and lab techs recommend dental-specific desktop printers, many of them use cheaper, more affordable 3D printers in their practice. The study aimed to compare the accuracy of two commercial non-dental stereolithography (SLA) 3D printers with a dental 3D printer for diagnostic dental casts. Methods: A prototype stereolithographic (Standard Triangle/Tessellation Language (STL)) model of a dentoform was used as a master model to be printed by three 3D printers (n=10 for each printer). The casts were post-processed according to the individual manufacturer's recommendation and then scanned using a desktop dental lab scanner to produce STL files. The STL for each cast was superimposed onto the original STL master model file and dimensional discrepancies were measured. Results: The results demonstrated a clear hierarchy in the accuracy of the 3D-printed models. The dental-specific 3D printer, Form 3B (Formlabs, Somerville,USA), produced models with the highest accuracy, exhibiting an average deviation of 37±5 µm from the original master model. Among the non-dental printers, the Mars 2 Pro (Elegoo, Shenzhen, China) showed reasonable accuracy with an average deviation of 47±22 µm, while the QiDi Tech (Qidi Technology, Zhejiang, China)had a much larger average deviation of 649±75 µm, indicating poor accuracy. Statistical analysis confirmed significant differences in mean deviations between Form 3B and QiDi Tech (t-test; p<0.01)and between Form 3B and Mars 2 Pro(t-test; p=0.05). These findings highlight the superior performance of the dental-specific 3D printer. Dental-specific desktop SLA 3D printers appear to have better accuracy than non-dental desktop 3D printers. When a non-dental 3D printer is used, the accuracy of these 3D printers may or may not be sufficient for dental applications.

Differential roles of IL-6 and adrenomedullin in early diagnosis and mortality predictions in late-onset neonatal sepsis.

Diagnosing and predicting neonatal sepsis is challenging because of its nonspecific symptoms, lack of diagnostic criteria consensus, and absence of early, sensitive, and specific diagnostic laboratory tests. To evaluate the diagnostic and prognostic potential of adrenomedullin (ADM), interleukin-6 (IL-6), and C-reactive protein (CRP) in late-onset neonatal sepsis (LOS). We studied 53 neonates with culture-proven LOS by sampling at admission and on antibiotic treatment days 3 and 7. These data were compared with those of 22 healthy full-term controls sampled on day 3 before hospital discharge. Survivors and non-survivors in the sepsis group were analyzed separately. Coagulase-negative Staphylococcus was the most commonly detected pathogen. ADM (cutoff, 0.5 ng/mL) and CRP (cutoff, <5 mg/L) values aligned with manufacturer recommendations, while IL-6 levels (cutoff, 10 pg/mL) were higher than expected, likely due to labor stress. The median biomarker levels significantly distinguished neonates with sepsis from controls (p < 0.0001) at all time points with ADM and IL-6 levels elevated at admission, indicating their potential as early diagnostic markers. CRP level was diagnostically useful starting on day 3. Prognostically, IL-6 (p < 0.001) and ADM (p < 0.05) differentiated survivors from non-survivors; however, only IL-6 consistently predicted mortality at all time points (area under the curve [AUC] > 0.90). ADM and CRP levels showed poor prognostic value (AUC < 0.70). ADM and IL-6 demonstrated strong diagnostic utility in early LOS, whereas CRP became relevant later. IL-6 was the only reliable biomarker for predicting mortality, supporting its integration into clinical protocols. Combining IL-6 with CRP may enhance early detection and management, potentially improving neonatal outcomes. IL-6 is a robust biomarker for the early diagnosis and prognosis of LOS. Incorporating IL-6 into clinical practice with CRP could improve early neonatal LOS diagnosis and patient outcomes.

Towards Green Dentistry: Evaluating the Potential of 4D Printing for Sustainable Orthodontic Aligners with a Reduced Carbon Footprint.

Clear aligners have transformed orthodontic care by providing an aesthetic, removable alternative to traditional braces. However, their significant environmental footprint, contributing to approximately 15,000 tons of plastic waste annually, poses a critical challenge. To address this issue, advancements in 4D printing have introduced "smart" aligners with shape memory properties, enabling reshaping and reducing the number of aligners required per treatment. This study focuses on ClearX aligners, an innovative 4D-printed solution aimed at extending usage duration and minimizing environmental impact. Using a comprehensive suite of tests, including morphological, optical, and mechanical evaluations conducted via scanning electron microscopy, UV-Vis spectroscopy, infrared spectroscopy, and bending and strain assessments, we evaluated the optical and mechanical stability of the ClearX material before and after thermal activation. Our results demonstrate that ClearX aligners retain their structural and functional properties after reshaping. Temporary changes in transparency, observed only under prolonged treatment durations exceeding manufacturer recommendations, are fully reversible within 12 h and do not compromise the aligner's usability. These findings support the potential of ClearX aligners to effectively combine patient-centered, high-quality orthodontic care with sustainable practices.

Comparison of survival time of three adhesive materials used in fixed space maintainer cementation by using ball milling machine: An in vitro study

Background: Premature primary tooth extraction causes loss of arch length, therefore; space preservation is a critical step to prevent space closure that can lead to future malocclusion. This can be achieved by using a space maintainer. Thus study's objective was to assess and contrast the survival of three different luting materials used to cement fixed space maintainers an in vitro study. Materials and Methods: This study used 30 extracted human third molars without caries, cracks, or chemical pretreatment. They were divided into three groups of ten samples (n = 10). The adhesives selected in this study were Relyx Luting 2 (resin modified glass ionomer), TOTALCEM (self-etching, self-adhesive, resin cement, dual cure) and Transbond Plus Light Cure band adhesive (compomer). Manufacturer recommendations for bonding were followed after cleaning and polishing for all surfaces of the teeth. To distinguish the specimens, the middle of the root was drilled with a handpiece and marked with a red marker, then incubated for 24 h at 37 °C before being transferred to a ball mill machine to induce mechanical stress. The machine was opened to check for any failed specimen. This continued until all bands were removed from the teeth. The data was analyzed using log-rank Kaplan-Meier and Bonferroni post hoc tests at p 0.05. Results: the mean survival time of bands cemented with TOTALCEM and RelyX Luting 2 significantly longer than bands cemented with Transbond Plus Light Cure band adhesive (P&lt;0.001). Conclusion: band retention with TOTALCEM and RelyX Luting2 superior than bands cemented with Transbond Plus Light Cure Band Adhesive.

Accuracy of volume measurements by a clinical spirometer in multiple veterinary hospitals.

Spirometry devices, which are components of many anaesthesia machines, are commonly used to assess lung mechanics during anaesthesia. Spirometry calibration usually adheres to manufacturer recommendations without established guidelines. Although more accurate and less variable than inbuilt spirometry in certain General Electric anaesthesia ventilators, near-patient spirometry lacks adequate evaluation. We assessed near-patient spirometers' performance using Pedi-lite and D-lite flow sensors. Certified 1 L calibration syringes were used on 67 monitors located in 14 veterinary hospitals. Three consecutive inspired and expired volume values displayed by the monitors for each volume of the calibration syringe were recorded. Volumes studied were 50, 100, 150, 250, 300 mL for Pedi-lite and 150, 300, 450, 500, 750 mL for D-lite. Measured and targeted volumes were averaged, agreement error calculated. Accuracy was assessed plotting agreement errors against calibration volumes. A linear mixed-effects model was used to obtain linear regression between the error and the calibration volume. Mean, differential and proportional bias, limits of agreement, claimed accuracy and 10% clinical tolerance were calculated and displayed. Differences among monitors were evaluated using the Friedman rank sum test, differences between inspired and expired volumes using the Wilcoxon signed-rank. Inter-monitor variability for inspired and expired volume readings using both sensors was high; intra-monitor variability was low. The error magnitude was independent of volumes evaluated. Using Pedi-lite, only a minority of measurements met manufacturer's specification or a 10% clinical tolerance; both inspired and expired volumes were significantly underestimated. Using D-lite, superior performance was demonstrated for volumes between 300 and 750 mL (mean biases close to zero and the majority of measurements meeting manufacturer's specifications and clinical tolerance). The difference between measured inspired and expired volumes with both sensors was significant. These results support caution when interpreting clinical measurements of lung volumes and mechanics in anaesthetised patients when using these sensors. This is particularly important in smaller patients where lung volumes are below 300 mL. Trends should be reliable.

Exchange rates of second generation Microcuff® pediatric endotracheal tubes in children weighing more than 3 kg : A retrospective audit.

Cuffed endotracheal tubes (cETT) pose the potential advantage of an infrequent need for reintubation in pediatric patients compared to uncuffed tubes. The aim of this study was to investigate tube exchange rates using second generation Microcuff® pediatric endotracheal tubes (PET) with an adapted sizing recommendation in alarge single institution cohort of children and to identify potential variables associated with an elevated risk of tube exchange. Patient data obtained from the electronic patient data management system of the Department of Anesthesia, University Children's Hospital Zurich, Switzerland, were retrospectively assessed for demographic and anthropometric information, size of the internal tube diameter used for positive pressure ventilation and divergence from the size recommendation chart. Data from 14,188 children younger than 16years (median 5.3years) and weighing at least 3 kg who underwent oral or nasal tracheal intubation using second generation Microcuff® PET between 2009 and 2015 were included. Of 13,219 oral tracheal intubations 12,049 (84.9%) were performed according to the manufacturer's size recommendation and 1170 with divergent endotracheal tubes. The odds ratio (OR) of oral reintubation was 0.13% (95% confidence interval 0.08-0.22%) for cases using the manufacture's size recommendation correctly and 22.74% (95% confidence interval 20.42-25.23%) for patients intubated with anot recommended tube (p < 0.0001). These findings indicate that the second generation Microcuff® PETs can be reliably used with low tube exchange rates across the entire pediatric age range when the tube size is selected according to the manufacturer's size recommendation chart. Adherence to the manufacturer's tube size recommendation is urgently advised.

A comparative study of strength and surface properties of permanent 3D-printed resins with CAD-CAM milled fixed dental prostheses.

To compare the strength, surface roughness, and hardness of newly introduced permanent three-dimensional (3D)-printed resin in comparison with computer-aided design and computer-aided manufacturing (CAD-CAM) milled materials. Three 3D-printed resins (NextDent C&B, Formlabs Permanent Crown, and VarseoSmile Crownplus) and two CAD-CAM milled (IPS e.max ZirCAD LT and VITA Enamic) resins were used to fabricate discs specimens. A total of 200 disc specimens were fabricated according to manufacturer recommendations. Within each group, half of the specimens were subjected to thermal cycling (5°C-55°C, the 30s, 5000 cycles). Aged and nonaged specimens were evaluated for biaxial flexural strength (BFS), surface roughness, and hardness. Results were statistically analyzed using analysis of variance (ANOVA) and t-tests (α=0.05). Significant differences (p<0.05) were observed in the BFS, surface roughness, and hardness between the 3D-printed and milled groups, before and after thermal aging. Overall, the CAD-CAM milled ceramic group had superior strength, surface roughness, and hardness when compared to all other groups (p<0.001), except for surface roughness after thermal aging, which was similar in all groups (p=0.063). Within each group, there was no significant difference (p>0.05) in surface roughness after thermal aging. BFS values of 3D-printed materials were statistically similar. In terms of surface roughness, Formlabs specimens displayed the highest value before and after thermal cycling, when compared to other 3D-printed materials. Regarding hardness, the VarseoSmile Crown plus group demonstrated the highest values compared to other 3D-printed materials, before and after thermal cycling. Permanent 3D-printed resins have lower strength than CAD-CAM milled materials. 3D-printed permanent resin materials exhibited high roughness and comparable hardness to CAD-CAM materials. Thermal aging negatively affected the properties of 3D-printed permanent crowns. Owing to the low strength of 3D-printed permanent resins, they may not be recommended for clinical practice until further improvements in flexural strength are made to meet clinical standards.

Evaluation of flexural strength of additively manufactured resin materials compared to auto-polymerized provisional resin with and without hydrothermal aging

PurposeAdditive manufacturing (AM) technologies are used to fabricate 3D-printed provisional dental restorations. The purpose of this study was to investigate the flexural strength of 3D-printed resins and compare their mechanical performance with those of conventional resins indicated for provisional restorations. Materials and methodsThis study included six different 3D-printed resin materials, namely (Nextdent (ND); Temp PRINT (TP); Optiprint temp (OT); 3Delta Etemp (DE); Saremco print | CROWNTEC (SA); MED690 (ST)), and one conventional (Protemp (PT)) (Control) provisional resin material. Specimens (N = 168) were prepared (25x2x2 mm3) following ISO 10477:2018 guidelines for temporary materials using a printer (Asiga MAX 3D). Post-processing was accomplished following each manufacturer's recommendation. While half of the specimens were tested after 24 H without aging, the other half was subjected to thermomechanical aging in a custom-made chewing simulator (1.200.000 cycles, 5 °C and 55 °C). Flexural strength of the specimens was determined using a Universal Testing Machine. Data were analyzed using two-way ANOVA followed by Tukey's post-hoc test (α = 0.05). Weibull modulus for each group was calculated based on parametric distribution analysis of censored data for maximum fracture load. ResultsNo significant difference was observed in mean flexural strength (MPa) when non-aged and aged conditions were compared in the OT and PT groups (p>0.05). Groups ND, SA, TP, DE, and ST presented significant differences ranging between 12.67 and 57.39 MPa (p<0.05). All groups presented lower shape and scale values in aged groups compared to their non-aged counterparts. While OT and PT maintained their flexural strength after aging, ND exhibited the highest decrease (30%), followed by DE (23.8%), SA (16.2%), TP (12%), and ST (8.6%) in descending order. Weibull modulus decreased as a function of aging except in group ST. ConclusionSignificant effect of themomechanical aging especially on ND and DE materials should be considered with caution when such materials are indicated as interim or long-term interim provisional restorations. SA and TP exceeded the expectations from a provisional material compared to that of the conventional control material PT.

Analysis of user behavior and energy-saving potential of electric water heaters

As global energy resources get more limited and environmental problems worsen, it is crucial to enhance energy efficiency and reduce energy consumption in end-use products. This research focuses on electric water heaters, a significant household energy consumer, and collects a large amount of data through questionnaires and analyzes the current usage patterns of water heater use, as well as the impact of the users’ personal characteristics and energy-saving consciousness on usage behaviors. It also evaluates the energy-saving potential under different scenarios, considering both consumer behaviors and product efficiency levels. Results indicate that a substantial number of users still purchase high-energy-consuming water heaters and fail to adjust temperatures according to their specific needs, resulting in considerable energy waste. Electric water heaters exhibit significant potential for energy savings, with the efficiency of the product and user behaviors identified as key factors influencing overall energy consumption. The study provides important insights into the usage behavior of electric water heaters and offers actionable recommendations for manufacturers and government agencies: advocating the use of certified energy-efficient water heaters, raising public awareness of energy efficiency in appliance use, etc., which is in line with the country’s goals of energy conservation and environmental sustainability.