Browsing by Issue Date, starting with "2025-07-11"
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- Managing space debris: risks, mitigation measures, and sustainability challengesPublication . Leal Filho, Walter; Dinis, Maria Alzira Pimenta; Hunt, Julian; Abubakar, Ismaila RimiSpace debris consists of non-functional, human-made objects remaining in Earth's orbit or entering the atmosphere, creating significant challenges for space operations. Current surveillance systems track nearly 40,000 larger debris fragments, yet it is estimated that hundreds of thousands of smaller pieces and millions of tiny, untracked particles further contribute to the risk of high-velocity collisions. These objects threaten spacecraft integrity, satellite functionality, and the long-term sustainability of space activities. This review article investigates the hazards posed by space debris, providing an overview of its impact on satellite operations, crewed space missions, and orbital stability. It examines risk mitigation strategies, including the enforcement of stricter disposal regulations, advancements in satellite design for controlled re-entry or deorbiting, and the active removal of large debris objects. A structured approach to space debris mitigation is also explored, outlining a proposed four-step strategy: designing spacecraft for impact resistance, implementing advanced remote tracking and monitoring systems, integrating onboard detection and avoidance mechanisms, and developing impact mitigation strategies to minimize damage. Additionally, the importance of enhanced tracking technologies and international cooperation is underscored, as collective efforts are necessary to address this escalating issue. Increasing awareness of the growing risks and exploring practical mitigation strategies strengthens ongoing efforts to safeguard space activities and ensure the long-term viability of Earth's orbital environment.
- Endodontic training with artificial teeth: students perceptionPublication . Cesario, Simone; Reis, Tiago; Barbosa, CláudiaObjectives: This study assessed students' perceptions of artificial teeth (AT) after completing the Endodontics I, II, and III curricular units at the Faculty of Health Sciences, Fernando Pessoa University, Porto, Portugal. Additionally, the study aims to review existing literature on students' perceptions of three-dimensional (3D) printed models used in pre-clinical training, identifying current challenges and future needs for improvement. Methods: A questionnaire was adapted, in which students had to compare AT with natural teeth (NT) in various aspects of anatomy and endodontic procedures. For the review of literature, a search was conducted in PubMed, MEDLINE, Scopus, and Web of Science up to March 16, 2025. The search included the keywords: endodontics; natural teeth; artificial teeth; 3D printed teeth; teaching; pre-clinical training and dental education, both individually and in combination using the Boolean operator “AND”. Relevant original research studies and review articles, published in English were selected without time restrictions. Additionally, cross-references were examined for further relevant studies. Results: Overall, students expressed a favorable opinion of AT in relation to external anatomy, radiopacity with files or gutta-percha, ease of acquisition, superior hygiene, and the simplicity of performing endodontic procedures. Conversely, students reported negative perceptions of AT concerning internal anatomy, pulp chamber size, canal shape and size, radiopacity, tactile sensation during access cavity preparation and pulp chamber entry, tactile feedback during endodontic procedures and debris removal, and the adequacy of AT for understanding endodontic techniques. Conclusion: The incorporation of AT into endodontic training represents a significant advancement toward standardization and improved efficiency in dental education. However, AT cannot fully replicate the tactile feedback and anatomical characteristics of NT. These findings underscore the need for continued development of AT that more closely mimics the properties of NT.