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Κυριακή 8 Ιανουαρίου 2023

Effect of sintering on the translucency of CAD‐CAM lithium disilicate restorations: a comparative in vitro study

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Abstract

Purpose

The available independent data on the translucency of novel pre and fully sintered chair-side computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate are limited. This comparative in vitro study evaluated the translucency degree of pre and fully sintered chairside CAD-CAM lithium disilicate crowns after optional, required, and additional firing processes.

Materials and Methods

One hundred and five maxillary left central incisor crowns manufactured by three different CAD-CAM lithium disilicate brands shade A1 were assigned into 7 groups as follows (n = 15): (1) n!ce Straumann without sintering; (2) n!ce Straumann with one additional sintering process; (3) n!ce Straumann with two additional sintering processes; (4) Amber Mill with one sintering process; (5) Amber Mill with two sintering processes; (6) IPS e.max CAD with one sintering process; (7) IPS e.max CAD with two sintering processes. The translucency of all crowns was evaluated with a color imaging spectrophotometer. All statistical analyses were performed using statistical software. A standard level of significance was set at α < 0.05.

Results

All the milled crowns presented different degrees of translucency, and additional sintering processes altered it. IPS E.max CAD with two (4.33 ± 0.26) and one (4.01 ± 0.15) sintering processes displayed the highest translucency, whereas n!ce Straumann with no sintering process provided the lowest value (2.82 ± 0.16).

Conclusions

The translucency of chairside lithium disilicate single-unit full-coverage restorations manufactured with subtractive technology was significantly influenced by the brand and the number of sintering processes. The traditional presintered IPS e.max CAD and the fully crystallized glass-ceramic n!ce Straumann considerably increased the translucency after one additional firing process, whereas Amber Mill decreased its translucency.

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Temporal trends in the incidence of malignant and non-malignant primary brain and central nervous system tumors by method of diagnosis in England, 1993-2017

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Abstract
Background
Several studies report increasing incidence of primary CNS tumors. The reasons for this are unclear.
Methods
Data on all 188,340 individuals diagnosed with a primary CNS tumor in England (1993-2017) were obtained from the National Cancer Registry. Data on all CT head and MRI brain scans in England (2013-2017) were obtained from NHS Digital. Age-sex-standardized annual incidence rates per 100,000 population (ASR) were calculated by calendar year, tumor behavior, tumor location and method of diagnosis. Temporal trends were quantified using average annual percent change (AAPC).
Results
The ASR for all CNS tumors increased from 13.0 in 1993 to 18.6 in 2017 (AAPC: 1.5%, 95% CI: 1.3, 1.7). The ASR for malignant tumors (52% overall) remained stable (AAPC: +0.5%, 95% CI: -0.2, 1.3), while benign tumors (37% overall) increased (AAPC: +2.6%, 95% CI: 1.2, 4.0). Among the 66% of benign tumors that were microscopically c onfirmed, the ASR increased modestly (AAPC: 1.3%, 95% CI: 0.5, 2.1). However, among the 25% of benign tumors that were radiographically confirmed, the ASR increased substantially (AAPC: 10.2%, 95% CI: 7.9, 12.5), principally driven by large increases in those aged 65+. The rate of CT head scans in Accident & Emergency (A&E) increased during 2013-2017, with especially large increases in 65-84 and 85+ year olds (AAPCs: 18.4% and 22.5%).
Conclusion
Increases in CNS tumor incidence in England are largely attributable to greater detection of benign tumors. This could be the result of increasing use of neuroimaging, particularly CT head scans in A&E in people aged 65+.
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Single‐cell transcriptomics dissects epithelial heterogeneity in HPV+ cervical adenocarcinoma

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Abstract

The intra- and inter-tumoral heterogeneity of epithelial cells in human papillomavirus (HPV)+ cervical adenocarcinoma (CEAD) remains largely unknown. To investigate this issue, we performed single-cell RNA sequencing on 19,229 epithelial cells sorted from three tumor samples of three patients with HPV+ CEAD. Six epithelial subclusters (Epi1 to Epi6) were identified that showed distinct gene expression. Among these, Epi1 and Epi4 had apparent tumor hallmarks and metabolic activities. Epi1 was highly enriched in hallmarks of hypoxia, IL2/STAT5 signaling, retinol metabolism, glycolysis, and arachidonic acid metabolism, while Epi4 was highly enriched in hallmarks of G2M checkpoint, E2F targets, DNA repair, PI3K/AKT/MTOR signaling, glycolysis, fatty acid degradation, TCA cycle, and glutathione metabolism. We also investigated inter-tumoral epithelial heterogeneity and found that Patient 1 was highly enriched for KRAS signaling and angiogenesis, while Patient 2 was highly enriched for epithelial-mesenchymal transition and TGF-β signaling, and Patient 3 was highly enriched for hypoxia, DNA repair, G2M checkpoint, and E2F targets. Using single-cell RNA sequencing, we revealed the intra- and inter-tumoral heterogeneity of epithelial cells in HPV+ CEAD, providing insights into the importance of personalized treatment for patients with HPV+ CEAD.

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