Purpose
To compare the accuracy of digital and conventional impression techniques for completely edentulous patients and to determine the effect of different variables on the accuracy outcomes.
...Materials and methods
A stone cast of an edentulous mandible with five implants was fabricated to serve as master cast (control) for both implant‐ and abutment‐level impressions. Digital impressions (n = 10) were taken with an intraoral optical scanner (TRIOS, 3shape, Denmark) after connecting polymer scan bodies. For the conventional polyether impressions of the master cast, a splinted and a non‐splinted technique were used for implant‐level and abutment‐level impressions (4 cast groups, n = 10 each). Master casts and conventional impression casts were digitized with an extraoral high‐resolution scanner (IScan D103i, Imetric, Courgenay, Switzerland) to obtain digital volumes. Standard tessellation language (STL) datasets from the five groups of digital and conventional impressions were superimposed with the STL dataset from the master cast to assess the 3D (global) deviations. To compare the master cast with digital and conventional impressions at the implant level, analysis of variance (ANOVA) and Scheffe's post hoc test was used, while Wilcoxon's rank‐sum test was used for testing the difference between abutment‐level conventional impressions.
Results
Significant 3D deviations (P < 0.001) were found between Group II (non‐splinted, implant level) and control. No significant differences were found between Groups I (splinted, implant level), III (digital, implant level), IV (splinted, abutment level), and V (non‐splinted, abutment level) compared with the control. Implant angulation up to 15° did not affect the 3D accuracy of implant impressions (P > 0.001).
Conclusion
Digital implant impressions are as accurate as conventional implant impressions. The splinted, implant‐level impression technique is more accurate than the non‐splinted one for completely edentulous patients, whereas there was no difference in the accuracy at the abutment level. The implant angulation up to 15° did not affect the accuracy of implant impressions.
Narrow-band imaging is an image-enhanced form of endoscopy used to observed microstructures and capillaries of the mucosal epithelium which allows for real-time prediction of histologic features of ...colorectal polyps. However, narrow-band imaging expertise is required to differentiate hyperplastic from neoplastic polyps with high levels of accuracy. We developed and tested a system of computer-aided diagnosis with a deep neural network (DNN-CAD) to analyze narrow-band images of diminutive colorectal polyps.
We collected 1476 images of neoplastic polyps and 681 images of hyperplastic polyps, obtained from the picture archiving and communications system database in a tertiary hospital in Taiwan. Histologic findings from the polyps were also collected and used as the reference standard. The images and data were used to train the DNN. A test set of images (96 hyperplastic and 188 neoplastic polyps, smaller than 5 mm), obtained from patients who underwent colonoscopies from March 2017 through August 2017, was then used to test the diagnostic ability of the DNN-CAD vs endoscopists (2 expert and 4 novice), who were asked to classify the images of the test set as neoplastic or hyperplastic. Their classifications were compared with findings from histologic analysis. The primary outcome measures were diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic time. The accuracy, sensitivity, specificity, PPV, NPV, and diagnostic time were compared among DNN-CAD, the novice endoscopists, and the expert endoscopists. The study was designed to detect a difference of 10% in accuracy by a 2-sided McNemar test.
In the test set, the DNN-CAD identified neoplastic or hyperplastic polyps with 96.3% sensitivity, 78.1% specificity, a PPV of 89.6%, and a NPV of 91.5%. Fewer than half of the novice endoscopists classified polyps with a NPV of 90% (their NPVs ranged from 73.9% to 84.0%). DNN-CAD classified polyps as neoplastic or hyperplastic in 0.45 ± 0.07 seconds—shorter than the time required by experts (1.54 ± 1.30 seconds) and nonexperts (1.77 ± 1.37 seconds) (both P < .001). DNN-CAD classified polyps with perfect intra-observer agreement (kappa score of 1). There was a low level of intra-observer and inter-observer agreement in classification among endoscopists.
We developed a system called DNN-CAD to identify neoplastic or hyperplastic colorectal polyps less than 5 mm. The system classified polyps with a PPV of 89.6%, and a NPV of 91.5%, and in a shorter time than endoscopists. This deep-learning model has potential for not only endoscopic image recognition but for other forms of medical image analysis, including sonography, computed tomography, and magnetic resonance images.
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Abstract Statement of problem Limited evidence is available for the marginal and internal fit of fixed dental restorations fabricated with digital impressions compared with those fabricated with ...conventional impressions. Purpose The purpose of this systematic review was to compare marginal and internal fit of fixed dental restorations fabricated with digital techniques to those fabricated using conventional impression techniques and to determine the effect of different variables on the accuracy of fit. Material and methods Medline, Cochrane, and EMBASE databases were electronically searched and enriched by hand searches. Studies evaluating the fit of fixed dental restorations fabricated with digital and conventional impression techniques were identified. Pooled data were statistically analyzed, and factors affecting the accuracy of fit were identified, and their impact on accuracy of fit outcomes were assessed. Results Dental restorations fabricated with digital impression techniques exhibited similar marginal misfit to those fabricated with conventional impression techniques (P>.05). Both marginal and internal gaps were greater for stone die casts, whereas digital dies produced restorations with the smallest gaps ( P <.05). When a digital impression was used to generate stereolithographic (SLA)/polyurethane dies, misfit values were intermediate. The fabrication technique, the type of restoration, and the impression material had no effect on misfit values ( P >.05), whereas die and restoration materials were statistically associated ( P <.05). Conclusions Although conclusions were based mainly on in vitro studies, the digital impression technique provided better marginal and internal fit of fixed restorations than conventional techniques did.
Bisphenol A (BPA) is an estrogen‐like compound, and an environmental hormone, that is commonly used in daily life. Therefore, it may enter the human body through food or direct contact, causing BPA ...residues in blood and urine. Because most studies focused on the analysis of BPA in reproductive cells or tissues, regarding evidence the effect of BPA on human retinal pigment epithelium (ARPE‐19) cells unavailable. Accordingly, the present study explored the cytotoxicity of BPA on ARPE‐19 cells. After BPA treatment, the expression of Bcl‐XL an antiapoptotic protein, in the mitochondria decreased, and the expression of Bax, a proapoptotic protein increased. Then the mitochondrial membrane potential was affected. BPA changed in mitochondrial membrane potential led to the release of cytochrome C, which activated caspase‐9 to promote downstream caspase‐3 leading to cytotoxicity. The nuclear factor (erythroid‐derived 2)‐like 2 (Nrf2) and heme oxygenase 1 (HO‐1) pathway play a major role in age‐related macular degeneration. Our results showed that expression of HO‐1 and Nrf2 suppressed by BPA. Superoxide dismutase and catalase, which Nrf2 downstream antioxidants, were degraded by BPA. AMP‐activated kinase (AMPK), which can regulate the phosphorylation of Nrf2, and the phosphorylation of AMPK expression was reduced by BPA. Finally, BPA‐induced ROS generation and cytotoxicity were reduced by N‐acetyl‐l‐cysteine. Taken together, these results suggest that BPA induced ARPE‐19 cells via oxidative stress, which was associated with down regulated Nrf2/HO‐1 pathway, and the mitochondria dependent apoptotic signaling pathway.
Drug-metabolizing enzymes (DMEs) and membrane transporters play important roles in the absorption, distribution, metabolism, and excretion processes that determine the pharmacokinetics of drugs. ...Inflammation has been shown to regulate the expression and function of these drug-processing proteins. Given that inflammation is a common feature of many diseases, in this review, the general mechanisms for inflammation-mediated regulation of DMEs and transporters are described. Also, evidences regarding the aberrant expression of these drug-processing proteins in several inflammatory diseases and age-related disorders are provided.
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•The roles of drug-metabolizing enzymes and transporters (the drug-processing proteins) in pharmacokinetics are introduced.•General mechanisms for the inflammation-mediated regulation of drug-processing proteins are described.•Examples for the regulation of drug-processing proteins in inflammation-related diseases are summarized.
Prevention and management of peri‐implant disease Sun, Teresa Chanting; Chen, Chun‐Jung; Gallucci, German O.
Clinical implant dentistry and related research,
August 2023, 2023-Aug, 2023-08-00, 20230801, Volume:
25, Issue:
4
Journal Article
Peer reviewed
Background
As more patients choose dental implants as their primary treatment option to restore edentulous ridges or to replace compromised dentition, preventive strategies for peri‐implant diseases ...and complications have become an important topic.
Purpose
The aim of the review article is to summarize the current available evidence on the potential risk factors/indicators for peri‐implant disease development and then focus on the preventive strategies for peri‐implant diseases and conditions.
Materials and Methods
After reviewing the diagnostic criteria and the etiology of peri‐implant diseases and conditions, evidence on the possible associated risk factors/indicators for peri‐implant diseases were searched and identified. Recent studies were also surveyed to explore the preventive measures for peri‐implant diseases.
Results
The possible associated risk factors of peri‐implant diseases can be divided into the following categories: patient‐specific factors, implant‐specific factors, and long‐term factors. Patient‐specific factors such as history of periodontitis and smoking have been conclusively associated with peri‐implant diseases, whereas findings on others, such as diabetes and genetic factors, remain inconclusive. It has been suggested that both implant‐specific factors, such as implant position, soft tissue characteristics, and the type of connection used, and long‐term factors, such as poor plaque control and a lack of maintenance program, have a strong impact on maintaining the health of a dental implant. Assessment tool for evaluating the risk factors can be a potential preventive measure for peri‐implant disease prediction, and it is needed to be properly validated.
Conclusion
Proper maintenance program for early intervention to control peri‐implant diseases at the initial stage and pretreatment assessment of the potential risk factors is the best strategy to prevent implant diseases.
Blood–brain barrier (BBB) characteristics are induced and maintained by crosstalk between brain microvascular endothelial cells and neighboring cells. Using in vitro cell models, we previously found ...that a bystander effect was a cause for Japanese encephalitis‐associated endothelial barrier disruption. Brain astrocytes, which neighbor BBB endothelial cells, play roles in the maintenance of BBB integrity. By extending the scope of relevant studies, a potential mechanism has been shown that the activation of neighboring astrocytes could be a cause of disruption of endothelial barrier integrity during the course of Japanese encephalitis viral (JEV) infection. JEV‐infected astrocytes were found to release biologically active molecules that activated ubiquitin proteasome, degraded zonula occludens‐1 (ZO‐1) and claudin‐5, and disrupted endothelial barrier integrity in cultured brain microvascular endothelial cells. JEV infection caused astrocytes to release vascular endothelial growth factor (VEGF), interleukin‐6 (IL‐6), and matrix metalloproteinases (MMP‐2/MMP‐9). Our data demonstrated that VEGF and IL‐6 released by JEV‐infected astrocytes were critical for the proteasomal degradation of ZO‐1 and the accompanying disruption of endothelial barrier integrity through the activation of Janus kinase‐2 (Jak2)/signal transducer and activator of transcription‐3 (STAT3) signaling as well as the induction of ubiquitin–protein ligase E3 component, n‐recognin‐1 (Ubr 1) in endothelial cells. MMP‐induced endothelial barrier disruption was accompanied by MMP‐mediated proteolytic degradation of claudin‐5 and ubiquitin proteasome‐mediated degradation of ZO‐1 via extracellular VEGF release. Collectively, these data suggest that JEV infection could activate astrocytes and cause release of VEGF, IL‐6, and MMP‐2/MMP‐9, thereby contributing, in a concerted action, to the induction of Japanese encephalitis‐associated BBB breakdown. GLIA 2015;63:1915–1932
Main Points
JEV‐infected astrocytes disrupted endothelial barrier integrity.
JEV infection caused astrocytes to release MMP‐2/MMP‐9, IL‐6, and VEGF.
IL‐6 and VEGF activated Jak2/STAT3/Ubr 1 leading to ZO‐1 degradation and endothelial barrier disruption.
Gastric cancer is the second leading cause of cancer-related death worldwide. The correlation of Helicobacter pylori and the etiology of gastric cancer was substantially certain. Cholesterol-rich ...microdomains (also called lipid rafts), which provide platforms for signaling, are associated with H. pylori-induced pathogenesis leading to gastric cancer. Patients who have been prescribed statins, inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase, have exhibited a reduced risk of several types of cancer. However, no studies have addressed the effect of statins on H. pylori-associated gastric cancer from the antineoplastic perspective. In this study, we showed that treatment of gastric epithelial cells with simvastatin reduced the level of cellular cholesterol and led to attenuation of translocation and phosphorylation of H. pylori cytotoxin-associated gene A (CagA), which is recognized as a major determinant of gastric cancer development. Additionally, a nationwide case-control study based on data from the Taiwanese National Health Insurance Research Database (NHIRD) was conducted. A population-based case-control study revealed that patients who used simvastatin exhibited a significantly reduced risk of gastric cancer (adjusted odds ratio (OR) = 0.76, 95% confidence interval (CI) = 0.70-0.83). In patients exhibiting H. pylori infection who were prescribed simvastatin, the adjusted OR for gastric cancer was 0.25 (95% CI = 0.12-0.50). Our results combined an in vitro study with a nationwide population analysis reveal that statin use might be a feasible approach to prevent H. pylori-associated gastric cancer.
There are limited therapeutic options for patients with Dravet syndrome (DS). The equilibrative nucleoside transporters 1 (ENT1) mediate both the influx and efflux of adenosine across the cell ...membrane exerted beneficial effects in the treatment of epilepsy. This study aimed to evaluate the anticonvulsant effect of the ENT1 inhibitor in an animal model of DS (Scn1aE1099X/+ mice). J7 (5 mg/kg) treatment was efficacious in elevating seizure threshold in Scn1aE1099X/+ mice after hyperthermia exposure. Moreover, the J7 treatment significantly reduced the frequency of spontaneous excitatory post‐synaptic currents (sEPSCs, ~35% reduction) without affecting the amplitude in dentate gyrus (DG) granule cells. Pretreatment with the adenosine A1 receptor (A1R) antagonist, DPCPX, abolished the J7 effects on sEPSCs. These observations suggest that the J7 shows an anticonvulsant effect in hyperthermia‐induced seizures in Scn1aE1099X/+ mice. This effect possibly acts on presynaptic A1R‐mediated signaling modulation in granule cells.
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