Aim
To evaluate differences in probing depth (PPD) with and without a prosthesis in implants without interproximal bone loss (IBL). Secondarily, to assess whether the difference in PPD measured with ...and without the crown was affected by diagnosis or implant location.
Materials and Methods
A cross‐sectional study was conducted in patients with a single screw‐retained implant‐supported crown in the posterior area, without IBL. PPD and was assessed before and after crown removal. A subgroup analysis compared healthy vs. mucositis implants and premolar vs. molar locations.
Results
In the 62 implants analysed (23 healthy and 39 with mucositis), the PPD was 1.15 mm (SD = 1.24 mm) deeper without the prosthesis than with it (p < .001). This difference was independent of the implant location (p > .05) except for buccal sites (p = .048). The mean PPD difference for implants with mucositis was 0.95 mm (SD = 1.19 mm; p < .001) while healthy implants had a mean PPD variation of 1.47 mm (SD = 1.29 mm; p < .001).
Conclusion
The presence of prosthesis in single‐tooth implants in the posterior area without IBL seems to lead to an underestimation of PPD that appears to be significant in implants diagnosed with mucositis, although the difference is even greater in healthy implants. Further studies are needed to confirm these findings.
Objective
To assess the effect of implantoplasty on the fracture resistance, surface roughness, and macroscopic morphology of standard diameter (4.1 mm) external connection dental implants.
Materials ...and methods
An in vitro study was conducted in 20 screw‐shaped titanium dental implants with an external connection. In 10 implants, the threads and surface were removed and polished with high‐speed burs (implantoplasty), while the remaining 10 implants were used as controls. The final implant dimensions were recorded. The newly polished surface quality was assessed by scanning electron microscopy (SEM) and by 3D surface roughness analysis using a confocal laser microscope. Finally, all the implants were subjected to a mechanical pressure resistance test. A descriptive analysis of the data was made. Also, Student's t tests were employed to detect differences regarding the compression tests.
Results
Implantoplasty was carried out for a mean time of 10 min and 48 s (standard deviation (SD) of 1 min 22 s). Macroscopically, the resulting surface had a smooth appearance, although small titanium shavings and silicon debris were present. The final surface roughness (Sa values 0.1 ± 0.02 μm) was significantly lower than that of the original (0.75 ± 0.08 μm Sa) (p = .005). There was minimal reduction in the implant's inner body diameter (0.19 ± 0.03 mm), and no statistically significant differences were found between the test and control implants regarding the maximum resistance force (896 vs 880 N, respectively).
Conclusions
Implantoplasty, although technically demanding and time‐consuming, does not seem to significantly alter fracture resistance of standard diameter external connection implants. A smooth surface with Sa values below 0.1 μm can be obtained through the use of silicon polishers. A larger sample is required to confirm that implantoplasty does not significantly affect the maximum resistance force of standard diameter external connection implants.
Mycobacterium Biofilms Esteban, Jaime; García-Coca, Marta
Frontiers in microbiology,
01/2018, Letnik:
8
Journal Article
Recenzirano
Odprti dostop
The genus
includes human pathogens (
and
) and environmental organisms known as non-tuberculous mycobacteria (NTM) that, when associated with biomaterials and chronic disease, can cause human ...infections. A common pathogenic factor of mycobacteria is the formation of biofilms. Various molecules are involved in this process, including glycopeptidolipids, shorter-chain mycolic acids, and GroEL1 chaperone. Nutrients, ions, and carbon sources influence bacterial behavior and have a regulatory role in biofilm formation. The ultrastructure of mycobacterial biofilms can be studied by confocal laser scanning microscopy, a technique that reveals different phenotypic characteristics. Cording is associated with NTM pathogenicity, and is also considered an important property of
strains. Mycobacterial biofilms are more resistant to environmental aggressions and disinfectants than the planktonic form. Biofilm-forming mycobacteria have been reported in many environmental studies, especially in water systems. NTM cause respiratory disease in patients with underlying diseases, such as old tuberculosis scars, bronchiectasis, and cystic fibrosis. Pathogens can be either slowly growing mycobacteria, such as
complex, or rapidly growing species, such as
. Another important biofilm-related group of infections are those associated with biomaterials, and in this setting the most frequently isolated organisms are rapidly growing mycobacteria.
can develop a biofilm which plays a role in the process of casseous necrosis and cavity formation in lung tissue.
also develops biofilms on clinical biomaterials. Biofilm development is an important factor for antimicrobial resistance, as it affords protection against antibiotics that are normally active against the same bacteria in the planktonic state. This antibiotic resistance of biofilm-forming microorganisms may result in treatment failure, and biofilms have to be physically eradicated to resolve the infection. New strategies with potential antibiofilm molecules that improve treatment efficacy have been developed. A novel antibiofilm approach focuses on
sp. An understanding of biofilm is essential for the appropriate management of patients with many NTM diseases, while the recent discovery of
biofilms opens a new research field.
Aim
The aim of this study was to assess the accuracy of periapical radiography in measuring peri‐implant bone levels.
Materials and Methods
Twenty‐five subjects with 46 implants in need of surgical ...treatment for peri‐implantitis were included in this cross‐sectional study. Prior to surgery, periapical radiographs were taken, a prediction of type of defect was made and radiographic peri‐implant bone levels (RxBL) were determined at the mesial and distal aspects. Intra‐operatively, the peri‐implant bone level (SurgBL) was assessed mesially, distally, buccally and orally and the type of defect was recorded. A paired t‐test was applied to detect differences between inter‐proximal RxBL and SurgBL. ANOVA was used to compare SurgBL at different circumferential positions.
Results
The mean inter‐proximal RxBL was 4.0 ± 2.2 mm and the mean inter‐proximal SurgBL was 5.3 ± 2.3 mm. The difference between RxBL and SurgBL was statistically significant (p = 0.014). There were no significant differences in SurgBL at the mesial, distal, buccal and oral aspects (p > 0.05).
Conclusions
The intra‐operatively measured peri‐implant bone levels were more apical than the radiographic bone levels. The intra‐operatively assessed peri‐implant bone levels (SurgBL) were similar at all the circumferential positions around the implant.
This article reviews the most important advances in the enzymatic synthesis of polyesters. In first place, the different processes of polyester enzymatic synthesis, i.e., polycondensation, ring ...opening, and chemoenzymatic polymerizations, and the key parameters affecting these reactions, such as enzyme, concentration, solvent, or temperature, are analyzed. Then, the latest articles on the preparation of polyesters either by direct synthesis or via modification are commented. Finally, the main bioapplications of enzymatically obtained polyesters, i.e., antimicrobial, drug delivery, or tissue engineering, are described. It is intended to point out the great advantages that enzymatic polymerization present to obtain polymers and the disadvantages found to develop applied materials.
This article reviews recent studies in the development of polyesters obtained via enzymatic synthesis and their possible applications in the field of biomedicine, such as in scaffolds, drug delivery, gene therapy, or antimicrobial systems.
Our study aims to assess the prevalence of CAPA (COVID-19-associated pulmonary aspergillosis) and describe the associated risk factors and their impact on mortality. A prospective study was ...conducted. We included patients with COVID-19 disease who were admitted to the ICU with a diagnosis of respiratory failur. Mycological culture and other biomarkers (calcofluor staining, LFD, LFA, PCR, GM, and B-D-glucan) were performed. A total of 300 patients were included in the study. Thirty-five patients were diagnosed with CAPA (prevalence 11.7%). During admission, 57 patients died (19%), and, in the group of CAPA patients, mortality was 31.4%. In multivariate analysis, independent risk factors associated with CAPA diagnosis were age (OR: 1.05; 95% CI 1.01-1.09;
= 0.037), chronic lung disease (OR: 3.85; 95% CI 1.02-14.9;
= 0.049) and treatment with tocilizumab during admission (OR: 14.5; 95% 6.1-34.9;
= 0.001). Factors independently associated with mortality were age (OR: 1.06; 95% CI 1.01-1.11;
= 0.014) and CAPA diagnosis during admission (OR: 3.34; 95% CI 1.38-8.08;
= 0.007). CAPA is an infection that appears in many patients with COVID-19 disease. CAPA is associated with high mortality rates, which may be reduced by early diagnosis and initiation of appropriate antifungal therapy, so screening of COVID-19 ARDS (acute respiratory distress syndrome) patients for CAPA is essential.
Proteostasis mechanisms mediated by macroautophagy/autophagy are altered in neurodegenerative diseases such as Alzheimer disease (AD) and their recovery/enhancement has been proposed as a therapeutic ...approach. From the two central nodes in the anabolism–catabolism balance, it is generally accepted that mechanistic target of rapamycin kinase complex 1 (MTORC1)_ activation leads to the inhibition of autophagy, whereas adenosine 5′‐monophosphate (AMP)‐activated protein kinase (AMPK) has the opposite role. In AD, amyloid beta (Aβ) production disturbs the optimal neuronal/glial proteostasis. As astrocytes are essential for brain homeostasis, the purpose of this work was to analyze if the upregulation of autophagy in this cell type, either by MTORC1 inhibition or AMPK activation, could modulate the generation/degradation of β‐amyloid. By using primary astrocytes from amyloid beta precursor protein (APP)/Presenilin 1 (PSEN1) mouse model of AD, we confirmed that MTORC1 inhibition reduced Aβ secretion through moderate autophagy induction. Surprisingly, pharmacologically increased activity of AMPK did not enhance autophagy but had different effects on Aβ secretion. Conversely, AMPK inhibition did not affect autophagy but reduced Aβ secretion. These puzzling data were confirmed through the overexpression of different mutant AMPK isoforms: while only the constitutively active AMPK increased autophagy, all versions augmented Aβ secretion. We conclude that AMPK has a significantly different role in primary astrocytes than in other reported cells, similar to our previous findings in neurons. Our data support that perhaps only a basal AMPK activity is needed to maintain autophagy whereas the increased activity, either physiologically or pharmacologically, has no direct effect on autophagy‐dependent amyloidosis. These results shed light on the controversy about the therapeutic effect of AMPK activation on autophagy induction.
Main Points
MTORC1 pathway activity is reduced in primary APP/PSEN1 astrocytes and its inhibition reduces amyloid secretion through moderate macroautophagy induction.
AMPK activation in APP/PSEN1 astrocytes does not trigger macroautophagy or enhance β‐amyloid clearance.
We conclude that mTORC1 plays a similar role to what we had previously reported in neurons, whereas AMPK has a significantly different function in primary astrocytes than in other reported cells.
La aspiración de esta investigación es la simplificación y la digitalización del derecho de las sociedades mercantiles no cotizadas. Se apuesta por un derecho societario simplificado y digitalizado ...como derecho facilitador de la iniciativa empresarial para la reconstrucción de un entorno emprendedor innovador, inclusivo y sostenible. Para la facilitación y la potenciación abogamos por la simplificación, la flexibilización y la innovación de la legislación. Se diseña una hoja de ruta para la configuración, la constitución y la organización de un sociedad mercantil simplificada y digitalizada. El propósito es adecuar el derecho mercantil de las sociedades no cotizadas a un entorno económico en constante mutación por las tecnologías, también por las emergentes y disruptivas, y por las incertidumbres, incrementadas en estos momentos de crisis sanitaria y económica.
Rheumatoid arthritis (RA) is a systemic autoimmune disease whose main extra-articular organ affected is the lung, sometimes in the form of diffuse interstitial lung disease (ILD) and conditions the ...prognosis. A multicenter, observational, descriptive and cross-sectional study of consecutive patients diagnosed with RA-ILD. Demographic, analytical, respiratory functional and evolution characteristics were analyzed to evaluate the predictors of progression and mortality. 106 patients were included. The multivariate analysis showed that the diagnostic delay was an independent predictor of mortality (HR 1.11, CI 1.01-1.23, p = 0.035). Also, age (HR 1.33, 95% CI 1.09-1.62, p = 0.0045), DLCO (%) (HR 0.85, 95% CI 0.73-0.98, p = 0.0246), and final SatO2 (%) in the 6MWT (HR 0.62, 95% CI 0.39-0.99, p = 0.0465) were independent predictor variables of mortality, as well as GAP index (HR 4.65, 95% CI 1.59-13.54, p = 0.0051) and CPI index (HR 1.12, 95% CI 1.03-1.22, p = 0.0092). The withdrawal of MTX or LFN after ILD diagnosis was associated with disease progression in the COX analysis (HR 2.18, 95% CI 1.14-4.18, p = 0.019). This is the first study that highlights the diagnostic delay in RA-ILD is associated with an increased mortality just like happens in IPF.
Oxidative Stability of Vegetal Oil-Based Lubricants Murru, Clarissa; Badía-Laíño, Rosana; Díaz-García, Marta E
ACS sustainable chemistry & engineering,
02/2021, Letnik:
9, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Lipids are widely distributed in nature and are one of the most important components of natural foods, synthetic compounds, and emulsions. To date, there is a strong social demand in the industrial ...sector for the use of sustainable products with a minimal environmental impact. Depending on their origin and composition, lipids can be employed as a plausible alternative as biodegradable lubricants in order to reduce the use of conventional mineral oil lubricants and mitigate their environmental impact. This perspective provides an overview of the advantages and constrains of vegetal oils under different lubrication regimes and the tribochemical reactions that can take place. Also, the different factors and pathways that influence their oxidation, the key role of moisture, and the changes of physical properties under pressure and temperature are reviewed. Special emphasis is devoted to the oxidation instability of fatty acids and vegetal oils and the physical and chemical approaches to improve oxidative and thermal stability are described in detail.
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