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Modern dentistry is turning towards natural sources to overcome the immunological, toxicological, aesthetic, and durability drawbacks of synthetic materials. Among the first biomaterials used as endosseous dental implants, mollusk shells also display unique features, such as high mechanical strength, superior toughness, hierarchical architecture, and layered, microporous structure. This review focusses on hydroxyapatite—a bioactive, osteoconductive, calcium-based material crucial for bone healing and regeneration. Mollusk-derived hydroxyapatite is widely available, cost-effective, sustainable, and a low-impact biomaterial. Thermal treatment coupled with wet chemical precipitation and hydrothermal synthesis are the most common methods used for its recovery since they provide efficiency, scalability, and the ability to produce highly crystalline and pure resulting materials. Several factors, such as temperature, pH, and sintering parameters, modulate the size, purity, and crystallinity of the final product. Experimental and clinical data support that mollusk shell-derived hydroxyapatite and its carbonated derivatives, especially their nanocrystaline forms, display notable bioactivity, osteoconductivity, and osteoinductivity without causing adverse immune reactions. These biomaterials are therefore highly relevant for specific dental applications, such as bone graft substitutes or dental implant coatings. However, continued research and clinical validation is needed to optimize the synthesis of mollusk shell-derived hydroxyapatite and determine its applicability to regenerative dentistry and beyond. [ABSTRACT FROM AUTHOR]

Background and Objectives: The COVID-19 pandemic has necessitated the development of reliable prognostic tools to predict patient outcomes and guide clinical decisions. This study evaluates the predictive utility of several clinical scores—PAINT, ISARIC4C, CHIS, COVID-GRAM, SOFA, and CURB-65—for in-hospital mortality among COVID-19 patients, comparing their effectiveness at admission and seven days post-symptom onset. Methods: In this retrospective cohort study conducted at the Clinical Emergency Hospital Pius Brînzeu in Timișoara, adult patients hospitalized with confirmed SARS-CoV-2 infection were included. The study was approved by the Local Ethics Committee, adhering to GDPR and other regulatory standards. Prognostic scores were calculated using patient data at admission and Day 7. Statistical analyses included ROC curves, Kaplan–Meier survival analysis, and multivariate Cox regression. Results: The study comprised 269 patients, with a notable distinction in outcomes between survivors and non-survivors. Non-survivors were older (mean age 62.12 years) and exhibited higher comorbidity rates, such as diabetes (55.56% vs. 31.06%) and cardiovascular diseases (48.15% vs. 29.81%). Prognostic scores were significantly higher among non-survivors at both time points, with PAINT and ISARIC4C showing particularly strong predictive performances. The AUROC for PAINT increased from 0.759 at admission to 0.811 by Day 7, while ISARIC4C demonstrated an AUROC of 0.776 at admission and 0.798 by Day 7. Multivariate Cox regression indicated that a PAINT score above 8.10 by Day 7 was associated with a hazard ratio (HR) of 4.9 (95% CI: 3.12–7.72) for mortality. Conclusions: The study confirms the strong predictive value of the PAINT, ISARIC4C, CHIS, COVID-GRAM, SOFA, and CURB-65 scores in determining mortality risk among hospitalized COVID-19 patients. These scores can significantly aid clinicians in early-risk stratification and resource prioritization, potentially enhancing patient management and outcomes in acute care settings. [ABSTRACT FROM AUTHOR]

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The COVID-19 pandemic underscores the need for accurate prognostic tools to predict patient outcomes. This study evaluates the effectiveness of four prominent COVID-19 prediction scores—PAINT, ISARIC4C, CHIS, and COVID-GRAM—at two critical time points: at admission and seven days post-symptom onset, to assess their utility in predicting mortality among hospitalized patients. Conducted at the Clinical Emergency Hospital Pius Brînzeu in Timișoara, this retrospective analysis included adult patients hospitalized with confirmed SARS-CoV-2 infection. Eligible patients had complete data for the scores at both time points. Statistical analysis involved ROC curves and logistic regression to assess the scores' predictive accuracy for mortality. The study included 215 patients, split into 139 survivors and 76 non-survivors. At admission, the PAINT, ISARIC4C, CHIS, and COVID-GRAM scores significantly differentiated between the survival outcomes (p < 0.0001). The best cutoff values at admission were 6.26 for PAINT, 7.95 for ISARIC4C, 5.58 for CHIS, and 0.63 for COVID-GRAM, corresponding to sensitivities of 85.47%, 80.56%, 88.89%, and 83.33% and specificities of 77.34%, 82.12%, 75.01%, and 78.45%, respectively. By day seven, the cutoff values increased, indicating deteriorating conditions in patients who eventually succumbed to the virus. The hazard ratios at admission for exceeding these cutoffs were significant: PAINT (HR = 3.45), ISARIC4C (HR = 2.89), CHIS (HR = 4.02), and COVID-GRAM (HR = 3.15), highlighting the scores' abilities to predict severe outcomes. One week post symptom onset, these scores' predictive values and corresponding hazard ratios increased, further validating their prognostic significance over time. The evaluated COVID-19 prediction scores robustly predict mortality at admission and become more predictive by the seventh day of symptom onset. These findings support the use of these scores in clinical settings to facilitate early identification and intervention for high-risk patients, potentially improving patient outcomes during the ongoing global health crisis. [ABSTRACT FROM AUTHOR]

Background: Removable prostheses have seen a fundamental change recently because of advances in polymer materials, allowing improved durability and performance. Despite these advancements, notable differences still occur amongst various polymer materials and processing technologies, requiring a thorough grasp of their mechanical, physical, and therapeutic implications. The compressive strength of dentures manufactured using various technologies will be investigated. Methods: Traditional, injection molding, and additive and subtractive CAD/CAM processing techniques, all utilizing Polymethyl methacrylate (PMMA) as the main material, were used to construct complete dentures. The specimens underwent a compressive mechanical test, which reveals the differences in compressive strength. Results: All the specimens broke under the influence of a certain force, rather than yielding through flow, as is characteristic for plastic materials. For each specimen, the maximum force (N) was recorded, as well as the breaking energy. The mean force required to break the dentures for each processing technology is as follows: 4.54 kN for traditional packing-press technique, 17.92 kN for the injection molding technique, 1.51 kN for the additive CAD/CAM dentures, and 5.9 kN for the subtractive CAD/CAM dentures. Conclusions: The best results were obtained in the case of the thermoplastic injection system and the worst results were recorded in the case of 3D printed samples. Another important aspect depicted is the standard deviation for each group, which reveal a relatively unstable property for the thermoplastic injected dentures. Good results here in terms of absolute property and stability of the property can be conferred to CAD/CAM milled group. [ABSTRACT FROM AUTHOR]

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Aim of the study: The aim of this study is to evaluate the resistance of different marginal fit geometries for a provissional fixed dental prothesis, which can have an impact on the periodontal health. Materials and methods: Acording to the principles of the tooth preparation, four types of marginal design were made: feather edge, rounded shoulder, chamfer and heavy chamfer. Using a direct technique, prepared teeth were poured into metal abutments, temporary composite resin crowns were made and cemented. All four abutments were analyzed using theoretical and experimental methods. Results: The results obtained from the mechanical tests were more reliable than those obtained from numerical analyses. A chamfer marginal finish line a pre prosthetic periodontal therapy can have greater impact on the soft tissue healing process. Conclusions: These preliminary studies enhance the idea of differentiating preparations for distinctive alternative prosthetic treatment plans. [ABSTRACT FROM AUTHOR]

Aim of the study In the field of digital dentistry, Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) systems have changed the fabrication of prosthetic restorations by fulfilling both the aesthetic requirements and mechanical performance. This study aims to highlight, by conducting a chromatic evaluation of zirconium oxide when altering the sintering parameters Materials and methods Four groups of zirconium oxide each group formed by 5 copings were made through milling and Exocad digital design software. The design was completed and the files were processed with the Zeno 4030 M1 milling machine (I-MES Wieland). Following milling, the copings were sintered in HTS MIHM-VOGT furnace at a maximum sintering temperature of 1650°C and heating rates of 30°C/min or a rapid rate of 90°C/min. Controlled cooling prevented rapid temperature decrease, thereby minimizing internal stress. Modifications of time and temperature parameters were applied to groups 2, 3, and 4. Chromatic analysis of the specimens was registered with the Vita Easy Shade spectrophotometer. Results It was found that adjustments in sintering temperature and timing are significantly affecting the chromatic outcomes of the non-metallic zirconium structures. Temperature adjustments facilitate the coalescence of zirconium oxide particles and the formation of a robust structure, with changes in it affecting the optical behaviour of the structure. Deviations from the optimum temperature and sintering timing parameters negatively affect the shade. Conclusions In conclusion, milled and sintered zirconium oxide structures can achieve aesthetic excellence, provided by the sintering protocol when the temperatures and sintering furnaces are accurately calibrated. [ABSTRACT FROM AUTHOR]

Aim of the study This manuscript summarizes important ethical considerations relevant to embryo research. The aim of this study was to assess the opinion of three categories of doctors regarding the ethical and legislative implications of scientific research on human embryos. Material and methods To assess the opinion of doctors about the use of human embryos in research, from a related point of view, a questionnaire with 10 questions was made. Each question has three possible answers. Results The results were analyzed according to the age criterion, as follows:18-25 graduated doctors; 26-45 young doctors; 45-65 adult doctors with experience in the field. Conclusions Following the interpretation of the questionnaires, it can be concluded that, in view of the group of people considered, graduated doctors have more knowledge about the current legislation and ethical measures that accompany scientific studies on human biological material. Also, the third group of doctors with experience in the field tend to show the same knowledge as the first group. [ABSTRACT FROM AUTHOR]

Copyright of dentalTarget is the property of dentalTarget and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of dentalTarget is the property of dentalTarget and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Animal experimental models are ruled out by respecting the 3Rs (Replacement, Reduction, Refinement) rules which governed the experimental research for decades with an increased tendency to minimize as much as it is possible any pain suffering or distress that the animals might feel. The chick embryo chorioallantoic membrane (CAM) model is an alternative to other experimental models due to its superior properties compared to other animal models. The CAM is painless by itself due to the lack of innervation and has no immune cells till the 11th day of incubation. Thus, it is extensively used for implanting malignant tumors and assessing them in relation to their metastatic and angiogenic potential. Also, various biomaterials from collagen to hard scaffolds can be implanted on the CAM surface and analyzed mainly related to their property of inducing inflammation. Dental research often uses mouse or rabbit models for experimental purposes. Different surgical techniques from experimentally induced periodontal disease to experimental dental implants may cause pain and suffering to animals. Due to all these arguments, the CAM model is a quick, cheap, and reliable alternative to other animal experimental models used in dental research. Despite its usefulness as an experimental model for different applications, ranging from inflammation studies to cancer research, the CAM model is insufficiently used in dental research. Currently, about 135 studies pertaining to this issue are available in PubMed, the majority of which focus on the reactivity of CAM vessels to various materials employed in dentistry. Limited data exist about the capacity of the CAM to promote osteogenic differentiation of dental stem cells or to enhance biomaterial integration into novel tissue architectures. The present review critically analyzed the use of the CAM model as an experimental tool in dental research. We selected from PubMed all the papers having as topic the CAM in dentistry by searching based on the following keywords: " chorioallantoic membrane, dentistry" or "chorioallantoic membrane, dental ". We focused on discussing the benefits and limitations of the CAM model in dental studies and its prospective role as a preclinical instrument for the assessment of dental tissues, biomaterials, or different dentistry-related substances prior to their use for various purposes in dental clinical practice. ​​​​​​The impact of the CAM model-derived preclinical findings on clinical practice will be also stated by mentioning "pros and cons" arguments. The last part of the present paper reviewed the perspective of CAM assay used in combination with other experimental techniques such as tooth organoids and also the strengths and weaknesses of other species CAM assays recently developed in ostrich and Nile crocodile CAMs., Competing Interests: Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Caplar et al.)