Does the choice of the measuring technique affect the comparison of fit between zirconia and cobalt-chromium prostheses?

AIMS: The objectives of the study were to compare the adaptation of presintered zirconia and cobalt- chromium prostheses using microcomputed tomography (µCT), scanning electron microscopy (SEM), and stereomicroscope (SM). MATERIALS AND METHODS: Twenty-four fixed dental prostheses (FDPs) were fabricated on metal abutments, duplicated from maxillary first premolar and first molar prepared on a typodont model. Teeth were reduced to obtain chamfer of 1.2 mm and reduction occlusaly of 2 mm occlusal. Scanning of the abutments was done with random assignment to two groups receiving the FDPs made from soft-milled Co-Cr (n = 12) and zirconia (n = 12). Marginal and internal gaps were assessed using three evaluation techniques (X-ray microcomputer tomography, SEM, and stereomicroscopy). STATISTICAL ANALYSIS USED: Comparison of the results was made using Levene and analysis of variance tests (α =0.05). RESULTS: Irrespective of the material tested, statistical differences were found between the measuring techniques (P = 0.001 overall); the obtained mean gaps were for CT scan (92.60 ± 13.31), for SEM (101.92 ± 23.03), and for SM (113.44 ± 14.68): the multiple comparisons between techniques found a significant difference between CT and SM (P < 0.001), and SEM and SM (P = 0.025). When materials were compared within each measuring technique, Co-Cr showed lower values compared to zirconia in SEM (P < 0.001) and Stereo (P = 0.049); similar results were found in CT. CONCLUSIONS: Results values differed with the chosen measuring technique. Co-Cr prostheses had a better fit than zirconia prostheses in SEM and Stereo. µCT showed comparable results to SEM, smaller than SM results.

Does the Build Orientation Parameter Affect the Fit of Fixed Partial Dentures Fabricated by Additive Manufacturing?

PURPOSE: This in vitro study evaluated the adaptation of cobalt-chromium (Co-Cr) fixed dental prostheses (FDPs) fabricated by selective laser melting (SLM) with different build angles. MATERIALS AND METHODS: Maxillary right first premolars and first molars from a typodont were prepared with 1-mm chamfer, 2-mm occlusal reduction, and total taper of 8 degrees to receive three-unit FDPs. After framework design, data were sent to a laser machine, and 30 specimens were fabricated from Co-Cr metal powder by SLM. Specimens were assigned to three groups (n = 10 per group) with different build angles of 0 (A0), 30 (A30), and 45 (A45) degrees. Marginal and internal fit were evaluated. Results were compared among build orientation groups and abutments. Data were analyzed using the Levene test, t test, and analysis of variance (α = .05). RESULTS: A statistical difference was found between different angle groups (P = .015). At the abutment level, a significant difference was found in the gap values between build orientation groups for the molars (P = .048). Group A0 reported the smallest mean discrepancy values, and group A45 the highest. Statistical differences were found between group A45 and groups A0 (P < .001) and A30 (P < .024). CONCLUSIONS: The fit of printed metal FDPs was affected by the build orientation but remained clinically acceptable.

Assessing the potential of GPT-4 to perpetuate racial and gender biases in health care: a model evaluation study.

BACKGROUND: Large language models (LLMs) such as GPT-4 hold great promise as transformative tools in health care, ranging from automating administrative tasks to augmenting clinical decision making. However, these models also pose a danger of perpetuating biases and delivering incorrect medical diagnoses, which can have a direct, harmful impact on medical care. We aimed to assess whether GPT-4 encodes racial and gender biases that impact its use in health care. METHODS: Using the Azure OpenAI application interface, this model evaluation study tested whether GPT-4 encodes racial and gender biases and examined the impact of such biases on four potential applications of LLMs in the clinical domain-namely, medical education, diagnostic reasoning, clinical plan generation, and subjective patient assessment. We conducted experiments with prompts designed to resemble typical use of GPT-4 within clinical and medical education applications. We used clinical vignettes from NEJM Healer and from published research on implicit bias in health care. GPT-4 estimates of the demographic distribution of medical conditions were compared with true US prevalence estimates. Differential diagnosis and treatment planning were evaluated across demographic groups using standard statistical tests for significance between groups. FINDINGS: We found that GPT-4 did not appropriately model the demographic diversity of medical conditions, consistently producing clinical vignettes that stereotype demographic presentations. The differential diagnoses created by GPT-4 for standardised clinical vignettes were more likely to include diagnoses that stereotype certain races, ethnicities, and genders. Assessment and plans created by the model showed significant association between demographic attributes and recommendations for more expensive procedures as well as differences in patient perception. INTERPRETATION: Our findings highlight the urgent need for comprehensive and transparent bias assessments of LLM tools such as GPT-4 for intended use cases before they are integrated into clinical care. We discuss the potential sources of these biases and potential mitigation strategies before clinical implementation. FUNDING: Priscilla Chan and Mark Zuckerberg.

Randomized Phase 2 Placebo-Controlled Trial of Nintedanib for the Treatment of Radiation Pneumonitis.

PURPOSE: Radiation pneumonitis (RP) is the most common dose-limiting toxicity for thoracic radiation therapy. Nintedanib is used for the treatment of idiopathic pulmonary fibrosis, which shares pathophysiological pathways with the subacute phase of RP. Our goal was to investigate the efficacy and safety of nintedanib added to a prednisone taper compared with a prednisone taper alone in reducing pulmonary exacerbations in patients with grade 2 or higher (G2+) RP. METHODS AND MATERIALS: In this phase 2, randomized, double-blinded, placebo-controlled trial, patients with newly diagnosed G2+ RP were randomized 1:1 to nintedanib or placebo in addition to a standard 8-week prednisone taper. The primary endpoint was freedom from pulmonary exacerbations at 1 year. Secondary endpoints included patient-reported outcomes and pulmonary function tests. Kaplan-Meier analysis was used to estimate the probability of freedom from pulmonary exacerbations. The study was closed early due to slow accrual. RESULTS: Thirty-four patients were enrolled between October 2015 and February 2020. Of 30 evaluable patients, 18 were randomized to the experimental Arm A (nintedanib + prednisone taper) and 12 to the control Arm B (placebo + prednisone taper). Freedom from exacerbation at 1 year was 72% (confidence interval, 54%-96%) in Arm A and 40% (confidence interval, 20%-82%) in Arm B (1-sided, P = .037). In Arm A, there were 16 G2+ adverse events possibly or probably related to treatment compared with 5 in the placebo arm. There were 3 deaths during the study period in Arm A due to cardiac failure, progressive respiratory failure, and pulmonary embolism. CONCLUSIONS: There was an improvement in pulmonary exacerbations by the addition of nintedanib to a prednisone taper. Further investigation is warranted for the use of nintedanib for the treatment of RP.

The Effect of Firing Cycles on the Fit of Cobalt-Chromium Multiunit Prostheses Fabricated by Additive Manufacturing.

PURPOSE: The effect of annealing and firing cycle on the adaptation of cobalt-chromium (CoCr) restorations fabricated by additive manufacturing has been poorly documented. This study compared the marginal and internal fit of CoCr three-unit fixed dental prostheses before and after firing cycles. MATERIAL AND METHODS: The first right maxillary premolar (MP) and molar (MM) on a typodont model, were prepared with a circumferential 1.2 mm chamfer, 2 mm occlusal reduction, and total taper of 8 degrees, to receive 3-unit fixed dental prostheses (FDP). After the framework design, 20 framework specimens were fabricated using CoCr metal powder by selective laser melting. The replica technique was used for marginal and internal fit measurements in mesiodistal and buccolingual planes. The specimens were submitted to an annealing process, and to ceramic firing protocol. Measurements were repeated after each firing cycle. The data were compared by using Levene test, t-test, and analysis of variance (ANOVA) (α = 0.05). RESULTS: A significant difference was found in the total intaglio surface discrepancy between the 3 treatments. The annealing treatment induced a statistical difference in the discrepancy value compared to the as printed state (p = 0.028). A significant difference was detected between the initial manufacturing phase and the ceramic layering firing cycle (p = 0.003). CONCLUSIONS: Firing cycles induced an alteration of the frameworks adaptation.

Evaluation of ceramic adherence to cobalt-chromium alloys fabricated by different manufacturing techniques.

STATEMENT OF PROBLEM: Selective laser melting has been increasingly used in the fabrication of metal-ceramic prostheses. The longevity of the prostheses depends on the strength of the metal-ceramic bond, which may differ with the framework manufacturing technique. PURPOSE: The purpose of this in vitro study was to compare the bond strength of ceramic to cobalt-chromium (Co-Cr) alloys fabricated by different manufacturing methods. MATERIAL AND METHODS: Sixty Ø15×2-mm disk-shaped specimens were prepared and assigned to 3 groups (n=20) with different manufacturing methods: milled Co-Cr (M), selective laser melted Co-Cr (SLM), and cast Co-Cr (C). The disks were ceramic layered with a 2-mm thickness. Half of the specimens from each group were thermocycled. The shear bond strength (SBS) test was applied to all specimens. The microstructure changes after ceramic layering were evaluated by X-ray diffraction (XRD). The specimens' surface morphology was analyzed by using scanning electron microscopy (SEM). RESULTS: Thermocycling had a significant effect on SBS values in the SLM group (P=.017). Considering the registered Fmax (force inducing bonding failure), a significant difference was found between SLM and both M and C groups (P<.001). No significant difference was found between milled and cast Co-Cr (P=.885). The failure types were mostly mixed failures. Ceramic layering induced a crystallization increase in groups C and SLM. CONCLUSIONS: The adhesion strength of ceramic to Co-Cr differed with alloy composition and manufacturing technique. The aging process influenced the results in the SLM group.

Does the Build Orientation Parameter Affect the Fit of Fixed Partial Dentures Fabricated by Additive Manufacturing?

PURPOSE: To evaluate the adaptation of cobalt-chromium (Co-Cr) fixed dental prostheses (FDPs) fabricated using selective laser melting (SLM) with different build angles. MATERIALS AND METHODS: The maxillary right first premolar and molar from a typodont were prepared with a 1-mm chamfer, a 2-mm occlusal reduction, and a total taper of 8 degrees to receive three-unit FDPs. After framework design, the data were sent to a laser machine, and 30 specimens were fabricated from Co-Cr metal powder by SLM. Specimens were assigned to three groups (n = 10 each) with different build angles of 0 (A0), 30 (A30), and 45 (A45) degrees. The marginal and internal fit were evaluated, and the results were compared among the build orientation groups and abutments. Data were analyzed by using Levene test, t test, and analysis of variance (ANOVA; α = .05). RESULTS: A statistical difference was found between the different angle groups (P = .015). At the abutment level, a significant difference was found in the gap values between the build orientation groups for the molars (P = .048). Group A0 reported the smallest mean discrepancy values and group A45 the highest; statistical differences were found between groups A45 and A0 (P < .001) and A45 and A30 (P < .024). CONCLUSION: The fit of printed metal FDPs was affected by the build orientation but remained clinically acceptable.

Mouse phospholipid phosphatase 6 regulates dendritic cell cholesterol, macropinocytosis, and allergen sensitization.

Lipid phosphate phosphatases are a family of enzymes with diverse cellular metabolic functions. Phospholipid phosphatase 6 (PLPP6) is a regulator of cellular polyisoprenyl phosphates; however, its in vivo functions remain to be determined. Here, mouse PLPP6 was characterized to possess similar catalytic properties as the human enzyme. Plpp6 knockout mice (Plpp6 -/- ) were generated and displayed decreased airway allergen sensitization, pointing to a role for PLPP6 in the early events of lung allergic responses. Dendritic cell (DC) responses were investigated and endocytosis of allergen via macropinocytosis was decreased in Plpp6 -/- DCs that had lower cholesterol content. When reversed by cholesterol loading, the DC macropinocytosis defect is corrected. Adoptive transfer of Plpp6 -/- DCs to wild-type mice during sensitization was sufficient to decrease allergen-induced responses. Together, our findings have identified PLPP6 as a pivotal regulator of DC cholesterol content and macropinocytosis, cellular mechanisms that are important for pathologic responses in allergen-induced lung inflammation.

Analytical frameworks in colorectal cancer guidelines: development of methods for systematic reviews, their application and practical guidance for their use.

OBJECTIVES: Analytical frameworks are graphical representation of the key questions answered by a systematic review and can support the development of guideline recommendations. Our objectives were to a) conduct a systematic review to identify, describe and compare all analytical frameworks published as part of a systematic and guideline development process related to colorectal cancer (CRC), and b) to use this case study to develop guidance on how to conduct systematic reviews of analytical frameworks. METHODS: We developed a search strategy to identify eligible studies in Medline and Embase from 1996 until December 2020. We also manually searched guideline databases and websites to identify all guidelines and systematic reviews in CRC that used an analytical framework. We assessed the quality of the guidelines using the Appraisal of Guidelines for Research and Evaluation II tool. The systematic review was registered in International Prospective Register of Systematic Reviews, registration CRD42020172117. RESULTS: We screened 34,505 records and identified 1,166 guidelines and 3,127 systematic reviews on CRC of which five met our inclusion criteria. These five publications included four analytical frameworks in colorectal cancer (one update). We also describe our methodological approach to systematic reviews for analytical frameworks and underlying concepts for developing analytical framework using a bottom-up or top-down approach. CONCLUSION: Few guidelines and systematic reviews are utilizing analytical frameworks in the development of recommendations. Development of analytical frameworks should begin with a systematic search for existing analytical frameworks and follow a structured conceptual approach for their development to support guideline recommendations. Our methods may be helpful in achieving these objectives.

Effect of lamination layer thickness and abutment preparation on the fit of Co-Cr multi-unit prostheses fabricated by additive manufacturing: An in vitro study.

STATEMENT OF PROBLEM: Selective laser melting has been increasingly used in the fabrication of metal-ceramic prostheses. The lamination layer thickness may influence the fit of the restoration. However, data regarding its impact remain scarce. PURPOSE: The purpose of this in vitro study was to evaluate the marginal and internal fit of cobalt-chromium (Co-Cr) 3-unit frameworks fabricated by additive manufacturing with different melting layer thicknesses on different abutments. MATERIAL AND METHODS: The first right maxillary premolar and molar from a typodont were prepared with a circumferential 1.2-mm chamfer, 2-mm occlusal reduction, and total taper of 8 degrees to receive 3-unit fixed partial dentures. After framework design, the data were sent to a laser machine, and 30 specimens were fabricated from Co-Cr metal powder (Mediloy S-Co) by selective laser melting. Specimens were assigned to 3 groups (n=10) with different lamination layer thicknesses of 25 (L25), 50 (L50), and 100 (L100) µm. Marginal fit and internal fit were evaluated. Results were compared among layer thickness groups and abutments. Data were compared by using the Levene test, t test, and ANOVA (α=.05). RESULTS: A statistical difference was found between different layer thickness groups (P=.016), but not between abutments (P=.429). On the abutment level, significant difference was found in the gap values for the molars (P=.049) between layer thickness groups, but not for the premolars (P=.126). Group L25 reported the smallest mean discrepancy values, and group L100 reported the highest, with statistical difference found between group L100 and groups L25 (P<.001) and L50 (P<.025), but not between groups L25 and L50 (P=.094). CONCLUSIONS: The lamination layer thickness affected the adaptation of the metal frameworks. Framework fit did not significantly differ between abutments.

Nasolacrimal Duct Obstruction: An Unusual Presentation of Sarcoidosis.

Lacrimal drainage system disorders leading to epiphora are a common ophthalmologic complaint. When such a patient is identified, the ophthalmologist frequently collaborates with the otolaryngologist to perform a dacryocystorhinostomy (DCR). In rare cases, sinonasal sarcoidosis may lead to nasolacrimal duct obstruction (NLD) and dacryocystitis. A 48-year-old Caucasian female was referred to the Otolaryngology clinic for evaluation of a 6-month history of persistent right-sided nasal obstruction and epiphora. After physical examination and computerized tomography (CT) scan, she was diagnosed with right NLD with dacryocystitis. The patient underwent right endoscopic DCR. Pathology from the lacrimal bone and nasal tissue demonstrated noncaseating granulomas suggestive of sarcoidosis. Postoperative evaluation including lung CT scan confirmed systemic sarcoidosis. Nasolacrimal duct obstruction very rarely is the presenting symptom in patients with sarcoidosis. Imaging is necessary to rule out other causes of NLD, and histopathology is essential for diagnosis. Noncaseating granulomas are found along the nasal tissue and lacrimal sac, specifically in the subepithelial layer. Treatment consists of DCR, either endoscopic or external. Both approaches achieve long-lasting resolution of symptoms but may require revision from inflammation and scarring. There is no consensus on the use of intraoperative or postoperative steroids.

X-ray microtomographic evaluation of the absolute marginal fit of fixed prostheses made from soft Co-Cr and zirconia.

STATEMENT OF PROBLEM: The absolute marginal fit of CAD-CAM presintered fixed partial dentures has been poorly documented. PURPOSE: The purpose of this in vitro study was to evaluate the marginal fit of presintered cobalt-chromium (Co-Cr) and zirconia 3-unit fixed partial dentures by using X-ray microcomputed tomography (µCT). MATERIAL AND METHODS: A metal model was prepared from a typodont to receive fixed partial dentures (N=12). The maxillary first premolar and first molar were prepared with a circumferential 1.2-mm chamfer and 2-mm occlusal reduction. The dies were scanned and assigned to 1 of 2 groups to receive the prostheses made of presintered Co-Cr or presintered zirconia (n=6). Each framework was seated on its model without load application. The abutments were scanned by using µCT. A circle with 10 diameters, with a step of 18 degrees, was projected at the center of the obtained image. Absolute marginal discrepancy and marginal gap mean values were measured, and overextended and underextended margins determined. The data were analyzed by using the Levene t test and ANOVA (α=.05). RESULTS: No statistically significant difference was found in the marginal fit between the materials tested (P=.939). The mean values were 66 ±14 µm for Co-Cr and 61 ±12 µm for zirconia. The absolute marginal discrepancy mean value for the premolar was 69 ±12 µm and 41 ±9 µm for the molar (P<.001). Overextension was predominant for both materials tested, with a higher percentage reported for the zirconia group. CONCLUSIONS: Presintered alloys presented clinically acceptable adaptation with a predominance of marginal overextensions.

Inflammation resolution circuits are uncoupled in acute sepsis and correlate with clinical severity.

Sepsis is a critical illness characterized by dysregulated inflammatory responses lacking counter-regulation. Specialized proresolving mediators are agonists for antiinflammation and for promoting resolution, and they are protective in preclinical sepsis models. Here, in human sepsis, we mapped resolution circuits for the specialized proresolving mediators resolvin D1 and resolvin D2 in peripheral blood neutrophils and monocytes, their regulation of leukocyte activation and function ex vivo, and their relationships to measures of clinical severity. Neutrophils and monocytes were isolated from healthy subjects and patients with sepsis by inertial microfluidics and resolvin D1 and resolvin D2 receptor expression determined by flow cytometry. The impact of these resolvins on leukocyte activation was determined by isodielectric separation and leukocyte function by stimulated phagolysosome formation. Leukocyte proresolving receptor expression was significantly higher in sepsis. In nanomolar concentrations, resolvin D1 and resolvin D2 partially reversed sepsis-induced changes in leukocyte activation and function. Principal component analyses of leukocyte resolvin receptor expression and responses differentiated sepsis from health and were associated with measures of sepsis severity. These findings indicate that resolvin D1 and resolvin D2 signaling for antiinflammation and resolution are uncoupled from leukocyte activation in early sepsis and suggest that indicators of diminished resolution signaling correlate with clinical disease severity.

Effect of ceramic layering on the fit of cobalt-chromium alloy 3-unit fixed dental prostheses fabricated by additive, soft milling, and casting technologies.

STATEMENT OF PROBLEM: The change in fit after ceramic layering of additively manufactured cobalt-chromium alloy frameworks has not been evaluated extensively. PURPOSE: The purpose of this in vitro study was to compare the fit of cobalt-chromium alloy fixed dental prostheses fabricated by different techniques before and after ceramic layering. MATERIAL AND METHODS: A cobalt-chromium alloy master model was prepared to receive a 3-unit fixed dental prosthesis. Sixty cobalt-chromium alloy frameworks (N=60) were manufactured by using 3 manufacturing techniques (n=20): selective laser melting (Mediloy S-Co), soft milling (Ceramill Sintron), and conventional casting as the control group (Girobond NB). The replica technique was used to measure the marginal and internal discrepancies. The frameworks were then layered with ceramic, and the same fit measuring procedure was repeated. The results were compared before and after ceramic layering within each group. The data were analyzed using the Levene, ANOVA, and paired-samples t tests (α=.05). RESULTS: A significant difference was found within groups before and after ceramic layering for selective laser melting (P=.006) and soft milling (P=.009) but not for conventional casting (P>.05). No statistical difference was reported in the marginal region for conventional casting group (P=.155) in contrast with the soft milling and selective laser melting groups (P=.003). Soft milling showed increased gap values in the marginal (P=.006) and occlusal regions (P=.004). CONCLUSIONS: Ceramic layering increased the discrepancy of the laser-sintered and milled frameworks, increasing the marginal discrepancy.

Comparison of fit accuracy of three-unit fixed ceramic-CoCr dental prostheses fabricated by three different techniques.

PURPOSE: To compare the precision of adaptation of cobalt-chromium (Co-Cr) three-unit fixed dental prostheses (FDPs) fabricated using different techniques. MATERIALS AND METHODS: A master model was prepared to receive a three-unit FDP. This model was duplicated 60 times from a silicone mold. The dies (N = 60) were scanned and divided into three groups (n = 20 each) to receive the FDPs made of pre-sintered Co-Cr (CS), laser-sintered Co-Cr (LS), or cast Co-Cr (Gi). Frameworks were layered with ceramic, and each framework was seated on its specific model. The replica technique was used to measure the marginal and internal discrepancies in the mesiodistal and buccolingual planes. Prepared silicone samples were examined with scanning electron microscopy. Obtained data were analyzed using Levene test, t test, and analysis of variance (α = .05). RESULTS: When overall mean discrepancy values were compared, in mesiodistal planes, LS showed better adaptation than Gi (P = .025). Similar adaptation was found for CS and Gi, and for CS and LS (P = .169 and P = 1.000, respectively). In buccolingual planes, the difference in fit was not significant among the three tested groups (P > .05). In a pairwise comparison between materials, a net increase in values between points 1 and 5 was noted (P = .57). Difference in discrepancy values within points was significant. This was confirmed at abutment level on some measurement points. Within each material, at abutment level, differences were significant at several measurement locations in both the mesiodistal and buccolingual planes. CONCLUSION: Within the limitations of this study, three-unit Co-Cr FDPs showed similar marginal and internal discrepancy values. Presintered and laser-sintered Co-Cr alloys can be considered for three-unit FDP fabrication.

FcεR1-expressing nociceptors trigger allergic airway inflammation.

BACKGROUND: Lung nociceptor neurons amplify immune cell activity and mucus metaplasia in response to an inhaled allergen challenge in sensitized mice. OBJECTIVE: We sought to identify the cellular mechanisms by which these sensory neurons are activated subsequent to allergen exposure. METHODS: We used calcium microscopy and electrophysiologic recording to assess whether vagal neurons directly respond to the model allergen ovalbumin (OVA). Next, we generated the first nociceptor-specific FcεR1γ knockdown (TRPV1Cre::FcεR1γfl/fl) mice to assess whether this targeted invalidation would affect the severity of allergic inflammation in response to allergen challenges. RESULTS: Lung-innervating jugular nodose complex ganglion neurons express the high-affinity IgE receptor FcεR1, the levels of which increase in OVA-sensitized mice. FcεR1γ-expressing vagal nociceptor neurons respond directly to OVA complexed with IgE with depolarization, action potential firing, calcium influx, and neuropeptide release. Activation of vagal neurons by IgE-allergen immune complexes, through the release of substance P from their peripheral terminals, directly amplifies TH2 cell influx and polarization in the airways. Allergic airway inflammation is decreased in TRPV1Cre::FcεR1γfl/fl mice and in FcεR1α-/- mice into which bone marrow has been transplanted. Finally, increased in vivo circulating levels of IgE following allergen sensitization enhances the responsiveness of FcεR1 to immune complexes in both mouse jugular nodose complex ganglion neurons and human induced pluripotent stem cell-derived nociceptors. CONCLUSIONS: Allergen sensitization triggers a feedforward inflammatory loop between IgE-producing plasma cells, FcεR1-expressing vagal sensory neurons, and TH2 cells, which helps to both initiate and amplify allergic airway inflammation. These data highlight a novel target for reducing allergy, namely, FcεR1γ expressed by nociceptors.

Fit Alteration of Presintered Co-Cr and Zirconia Multiple-Unit Prostheses After Ceramic Layering.

PURPOSE: The fit alteration after ceramic layering of soft Cobalt-Chromium (Co-Cr) and zirconia is poorly documented. This study compared the marginal and internal fit of presintered Co-Cr and zirconia three-unit fixed dental prostheses before and after ceramic veneering. MATERIALS AND METHODS: Co-Cr master model was prepared and duplicated 60 times to receive three-unit fixed dental prostheses (FDPs). Sixty dies were prepared, scanned and assigned to 3 groups (n = 20/group), to receive the FDPs made of presintered Co-Cr (CS), presintered zirconia (CZ) and cast Ni-Cr (Wi). Each framework was seated on its specific cast. A replica technique was used for marginal and internal discrepancy measurements in mesiodistal and buccolingual planes. Frameworks were ceramic veneered. Results were compared before and after ceramic layering within each group. Data were analyzed using the Levene, t test, and ANOVA (α = 0.05). RESULTS: Significant difference was found when gaps were compared within groups for CS and CZ but not for Wi. At the abutments level, significant difference was found for both premolars and molars in the buccolingual planes (p < 0.001). A multiple comparison between materials tested showed significant differences between presintered and cast Ni-Cr. No significant difference was detected between CS and CZ (p = 1.000). CONCLUSIONS: Although ceramic layering increased the discrepancy for presintered Co-Cr and zirconia, the marginal adaptation remained clinically acceptable.

Plasma Levels of Proresolving and Prophlogistic Lipid Mediators: Association With Severity of Respiratory Failure and Mortality in Acute Respiratory Distress Syndrome.

OBJECTIVES: Acute respiratory distress syndrome is characterized by an overly exuberant inflammatory state in the lung. Specialized proresolving mediators are endogenous agonists for the resolution of lung inflammation and injury in health, yet their association with acute respiratory distress syndrome severity and outcomes remains to be defined. In the current study, we investigate associations between plasma levels of specialized proresolving mediators and acute respiratory distress syndrome severity and mortality. DESIGN: Translational pilot study nested within a large prospective cohort of patients with risk factors for acute respiratory distress syndrome. SETTING: ICU from a large medical center. PATIENTS: Twenty-six Caucasian patients with acute respiratory distress syndrome and available plasma from early in critical illness. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Here, in samples from 26 acute respiratory distress syndrome patients, we examined plasma levels of select specialized proresolving mediators that promote lung injury resolution in preclinical systems, namely lipoxin A4 and maresin 1, and select prophlogistic lipid mediators linked to acute respiratory distress syndrome pathogenesis, namely cysteinyl leukotrienes and thromboxane B2. These mediators were detected by sensitive enzyme-linked immunosorbent assay: lipoxin A4 (assay range) (8.2-5,000 pg/mL), maresin 1 (7.8-1,000 pg/mL), cysteinyl leukotrienes (7.8-1,000 pg/mL), and thromboxane B2 (15.6-2,000 pg/mL). Lower plasma levels of specialized proresolving mediators were associated with increased duration of ventilatory support and ICU length of stay. Even in this small sample size, trends were evident for increased cysteinyl leukotrienes to specialized proresolving mediator ratios (cysteinyl leukotrienes/maresin 1 and cysteinyl leukotrienes/lipoxin A4) in acute respiratory distress syndrome nonsurvivors. CONCLUSIONS: Lower specialized proresolving mediator levels in acute respiratory distress syndrome patients may disrupt timely resolution of lung inflammation and/or injury and contribute to clinical severity and mortality.