Abstract:

This study aimed to evaluate stress distribution around two and four implants supporting maxillary implant overdentures retained by locator attachments, comparing full and partial palatal coverage designs. Four identical acrylic models representing completely edentulous maxillary arches were fabricated and covered with polyvinyl siloxane impression material to simulate the oral mucosa overlying the residual ridge. The models were divided into two main groups according to the number of installed implants (two or four), and each group was further subdivided based on palatal design (full or partial palatal coverage). Locator abutments (female components) were secured to the implants using an abutment driver, after which the prosthetic frameworks were constructed. Four strain gauges were bonded to each implant fixture using strain gauge cement to record strain values. A LLOYD digital loading device was employed to apply controlled compressive loads, and the resulting stresses around the implants were measured for each configuration.

Statistical analysis revealed a significant difference in stress values between two-implant overdentures with full palatal coverage (30.64 ± 17.47 N/m × 10²) and those with partial palatal coverage (49.72 ± 23.17 N/m × 10²), with higher stresses observed in the partial coverage design. In contrast, although four-implant overdentures with partial palatal coverage (8.77 ± 4.54 N/m × 10²) demonstrated higher mean stress values than those with full palatal coverage (5.51 ± 3.83 N/m × 10²), this difference was not statistically significant.

Within the limitations of this in vitro study, full palatal coverage design resulted in lower stress values compared to partial palatal coverage in two-implant-supported maxillary overdentures. For four-implant-supported overdentures, full palatal coverage also showed lower stress values; however, the difference was not statistically significant.

Abstract The prevalence of vitamin D deficiency has recently been recognized in different parts of the world, even affecting healthy populations. The deficiency of vitamin D can lead to rickets in children and osteomalacia in adults. No studies have been done in Gharyan city to evaluate the status of vitamin D among the population. So, this work aims to estimate the prevalence of vitamin D deficiency in the city, which is essential to maintaining the health of populations in general. This was a survey study conducted from September 2024 to December 2024, at some laboratories in the city: Alkama. Alnahda, Ayouser, Aldaka and Mashfa Gharyian. During the study period, 1718 analysis tests results of vitamin D were collected, classified to six groups according to age and characterized by measures of central tendency. The results showed that the age of the cases ranged from newborns to about 97 years, 30% males and 70 % females. Prevalence of vitamin D deficiency among female was more than males in all aged groups of the cases, about 62 % of the cases had low vitamin D levels (less than 30 ng/ml), the high level was 0.45% and 37% were at normal range. But the patients in categories 4, 5 had the highest number of cases. Spreading awareness among the population about the importance and vital role of the vitamin, explaining the risks of vitamin D deficiency and associated diseases among the population were recommended to reduce the Prevalence of vitamin D deficiency in Gharyan city

Arab societies, and particularly Libyan citizens, consume large quantities various types of bread daily. The

high level of bread consumption may negatively affect consumers' health due to the presence of several food

additives and hazardous chemicals that often exceed the permissible limits in bread products. In this study, nine

bread samples including Ciabatta bread, French bread, Barley bread, and Tanour bread were collected from

bakeries and markets distributed in the city of Kekla. These samples were analysed to determine the residues of

potassium bromate (KBrO3) using a spectrophotometric method depending on the redox reaction between

bromate ion in the samples and iodide ion of used reagent solubilized in an acidic medium. The study found that

the concentrations of KBrO3 in all studied samples ranged from 10.68 to 35.77 μg/g. This indicated that the levels

of KBrO3 in all investigated bread samples exceeded the permissible limit set by the American Food and Drug

Administration FDA (0.02 μg/g).

Abstract Classroom presentations represent an important aspect of activities that help English as a Second Language learners showcase their language skills, particularly speaking in front of others, and reveal the educational and psychological obstacles and challenges they face in performing these presentations at the best possible level. The study aims to identify the impact of language anxiety on classroom presentations by applying it to English as Foreign Language learners at Gharian University, which helps to investigate the level and type of anxiety that English as a Foreign Language students at the university suffer from during presentations. The study was conducted on various students of different semesters at University. The sample consisted of 100 students of both genders, divided into two groups (45 males and 45 females), during the academic year 2025-2026. The study relied on a questionnaire as the data collection tool, and the collected data was statistically analyzed using SPSS software. The results showed a high level of anxiety about learning English among the participating students for various reasons. A statistically significant inverse relationship was found between the level of English language anxiety among University students and the quality of their classroom presentations. Statistically significant differences were also found in language anxiety levels among students during classroom presentations, while no statistically significant differences were found between gender and anxiety levels in terms of their impact on the quality of classroom presentations. The stuconcluded with recommendations and suggestions to enhance the

Abstract

Natural dentin repair is a biologically mediated process that preserves tooth vitality through odontoblast activity and intracellular signaling pathways. This study employed a mixed methods design, combining laboratory experiments with descriptive analytical surveys of dentists in Egypt, to investigate the mechanisms of odontoblast differentiation and assess clinical knowledge and practices related to regenerative dentistry. Laboratory analyses included microscopic and molecular techniques to evaluate cellular signaling during dentin repair, while questionnaires were distributed to 100 dentists across public and private sectors. Data were analyzed using quantitative statistics, qualitative assessments, and integrative interpretation of laboratory and clinical findings. Results revealed significant positive correlations between dentists’ knowledge of intracellular signaling and their clinical practices, with Spearman correlation coefficients ranging from 0.52 to 0.65 (p = 0.01). A majority of respondents (80%) reported experience with mesenchymal stem cell therapy for craniofacial bone remodeling or dental tissue regeneration, and 70% observed improvements in bone density, while 65% reported enhanced dental tissue regeneration. Imaging studies were widely used, with 85% of participants undergoing radiographic or CT evaluations to monitor progress. Despite these encouraging outcomes, only 35% of dentists were familiar with molecular techniques targeting signaling pathways, and just 40% reported applying clinical strategies to enhance odontoblast differentiation. Notably, 75% expressed interest in specialized training to improve their knowledge and practices in regenerative dentistry. The study concludes that while theoretical awareness of dentin repair mechanisms is relatively strong, clinical application remains limited. Bridging this gap through structured training and evidence-based protocols will be essential for integrating molecular insights into routine dental practice, thereby improving dentin repair outcomes and long-term tooth vitality.