Comparison of external, internal flat-to-flat, and conical implant abutment connections for implant-supported prostheses: A systematic review and network meta-analysis of randomized clinical trials.

STATEMENT OF PROBLEM: The implant abutment connection interface has been considered one of the major factors affecting the outcome of implant therapy. However, drawbacks of traditional meta-analyses are the inability to compare more than 2 treatments at a time, which complicates the decision-making process for dental clinicians, and the lack of a network meta-analysis. PURPOSE: The purpose of this network meta-analysis was to assess whether the implant abutment connection influences the outcome of implant-supported prostheses. MATERIAL AND METHODS: An electronic search was undertaken to identify all randomized clinical trials comparing the effect of at least 2 different implant abutment connection designs published from 2009 up to May 2020. Outcome variables were implant survival rate, peri-implant marginal bone loss, and biologic and prosthetic complication rates at 12 months after prosthetic loading. Relevant information was extracted, and quality and risk of bias assessed. Pairwise meta-analyses and network meta-analyses based on a multivariate random-effects meta-regression were performed to assess the comparisons (α=.05 for all analyses). RESULTS: For peri-implant marginal bone loss and prosthetic complications, conical interfaces were determined to be the most effective, with significant differences when compared with external hexagonal connections (P=.011 and P=.038, respectively). No significant differences were found among the implant abutment connections in terms of survival and biologic complications (P>.05 in all direct, indirect, and mixed comparisons). CONCLUSIONS: After 1 year of loading, conical connections showed lower marginal bone loss and fewer prosthetic complications than external hexagonal connections. However, the implant abutment connection design had no influence on the implant survival and biologic complication rates.

Postgraduate education in radiation oncology during the COVID-19 pandemic - What did we learn?

Introduction: During the COVID-19 pandemic the ESTRO School who provides international non-profit postgraduate education in Radiation Oncology and related disciplines, including Medical Physics and Radiation Technology, had to close down all live educational activities and turn online, although having only limited experience. The paper describes the experience, discusses the limitations and benefits of online education and suggests directions for the future. Materials and methods: Data about format and feedback from attendees and faculty members from the course activities held in 2019, 2020 and 2021 were made available from the ESTRO School. Results: In 2020, all but two out of thirty live courses that happened before the lockdown were canceled. Among the 18 courses scheduled in the second half of the year, seven went online with a short notice. Each course planned their activities quite differently, from compressed courses with consecutive full days online program to courses over several weeks with a few hours online a week. Both numbers of participants and different nationalities were higher than live courses in 2019 for the seven courses happening online, and courses were well evaluated by participants and faculties. Roughly-one-third of participants would prefer online courses in the future. Discussion: Although online education was well received by the majority, pros and cons exist and especially the personal discussions and networking were missed. Online education and live education are not comparable but can complement each other. Careful balancing these activities in the future is important and strategies for online andragogy are needed.

Analysis of cavitation artifacts in Magnetic Resonance Imaging Thermometry during laser ablation monitoring.

Magnetic Resonance Thermometry Imaging (MRTI) holds great potential in laser ablation (LA) monitoring. It provides the real-time multidimensional visualization of the treatment effect inside the body, thus enabling accurate intraoperative prediction of the thermal damage induced. Despite its great potential., thermal maps obtained with MRTI may be affected by numerous artifacts. Among the sources of error producing artifacts in the images., the cavitation phenomena which could occur in the tissue during LA induces dipole-structured artifacts. In this work., an analysis of the cavitation artifacts occurring during LA in a gelatin phantom in terms of symmetry in space and symmetry of temperature values was performed. Results of 2 Wand 4 W laser power were compared finding higher symmetry for the 2 W case in terms of both dimensions of artifact-lobes and difference in temperature values extracted in specular pixels in the image. This preliminary investigation of artifact features may provide a step forward in the identification of the best strategy to correct and avoid artifact occurrence during thermal therapy monitoring. Clinical Relevance- This work presents an analysis of cavitation artifacts in MRTI from LA which must be corrected to avoid error in the prediction of thermal damage during LA monitoring.

Initial Results Obtained with the First TWIN VLBI Radio Telescope at the Geodetic Observatory Wettzell.

Geodetic Very Long Baseline Interferometry (VLBI) uses radio telescopes as sensor networks to determine Earth orientation parameters and baseline vectors between the telescopes. The TWIN Telescope Wettzell 1 (TTW1), the first of the new 13.2 m diameter telescope pair at the Geodetic Observatory Wettzell, Germany, is currently in its commissioning phase. The technology behind this radio telescope including the receiving system and the tri-band feed horn is depicted. Since VLBI telescopes must operate at least in pairs, the existing 20 m diameter Radio Telescope Wettzell (RTW) is used together with TTW1 for practical tests. In addition, selected long baseline setups are investigated. Correlation results portraying the data quality achieved during first initial experiments are discussed. Finally, the local 123 m baseline between the old RTW telescope and the new TTW1 is analyzed and compared with an existing high-precision local survey. Our initial results are very satisfactory for X-band group delays featuring a 3D distance agreement between VLBI data analysis and local ties of 1 to 2 mm in the majority of the experiments. However, S-band data, which suffer much from local radio interference due to WiFi and mobile communications, are about 10 times less precise than X-band data and require further analysis, but evidence is provided that S-band data are well-usable over long baselines where local radio interference patterns decorrelate.

Anticuerpos IgA en la leche humana: relación con enfermedad diarreica en el niño

Se analizaron 76 muestras de leche correspondientes a niños que presentaron infección por E. coli produtora de toxina lábil. E. coli productora de toxina estable. C. jejuni o rotavirus. De estas infecciones 23 fueron causadas por E. coli productora de toxina lábil, 19 por E. coli productora de toxina estable, 20 por C. jejuni y 14 por rotavirus. Los casos con infecciones mixtas fueron eliminadas del análisis estadístico. Todas las leches analizadas por toxina lábil de E. coli presentaron niveles detectables de anticuerpos IgA contra esta toxina. Al comparar los títulos de anticuerpos de la leche que ingerian los niños infectados que desarrollaron diarrea con aquellos infectados que permanecieron sanos, se encontró que los primeros ingerian leche con títulos significativamente más bajos que los segundos (p=0.028, Test de Mann-Whitney), siendo los riesgos relativos a desarrollar diarrea de 0.667 y 0.125 respectivamente (p = 0.025, Test de Fisher). Esta investigación sugiere que la presencia, en niveles adecuados, de anticuerpos IgA contra la toxina lábil de E. coli en la leche humana, protege al niño amamentado de la producción de diarrea causada por este microorganismo, aun cuando padezcan la infección. De las leches analizadas para el factor de neutralización de la toxina estable de E. coli, 13 presentaron actividad neutralizante en algún porcentaje y siete no presentaron ninguna actividad. Los resultados indican que no hay relación entre ingesta de leche con prueba de factor neutralizante positiva y protección de la producción de diarrea en el niño alimentado al pecho. Todas las leches analizadas para niveles de anticuerpos IgA contra C. jejuni y rotavirus presentaron niveles detectables de anticuerpos. Sin embargo, este estudio sugiere que la presencia de estos anticuerpos en la leche no se protegen al niño amamentado contra la producción de diarrea causada tanto por C. jejuni como por rotavirus