Optimized 3D printed zirconia-reinforced leucite with antibacterial coating for dental applications

OBJECTIVES

This study aims to produce by robocasting leucite/zirconia pieces with suitable mechanical and tribological performance, convenient aesthetics, and antibacterial properties to be used in dental crown replacement.

METHODS

Leucite pastes reinforced with 12.5%, 25%, and 37.5% wt. ZrO2 nanoparticles were prepared and used to print samples that after sintering were characterized in terms of density, shrinkage, morphology, porosity, mechanical and tribological properties and translucency. A coating of silver diamine fluoride (SDF) and potassium iodide (KI) was applied over the most promising material. The material's antibacterial activity and cytotoxicity were assessed.

RESULTS

It was found that the increase of ZrO2 reinforcement up to 25% enhanced both microhardness and fracture toughness of the sintered composite. However, for a superior content of ZrO2, the increase of the porosity negatively affected the mechanical behaviour of the composite. Moreover, the composite with 25% ZrO2 exhibited neglectable wear in chewing simulator tests and induced the lowest wear on the antagonist dental cusps. Although this composite exhibited lower translucency than human teeth, it was three times higher than the ZrO2 glazed material. Coating this composite material with SDF+KI conferred antibacterial properties without inducing cytotoxicity.

SIGNIFICANCE

Robocasting of leucite reinforced with 25% ZrO2 led to best results. The obtained material revealed superior optical properties and tribomechanical behaviour compared to glazed ZrO2 (that is a common option in dental practice). Moreover, the application of SDF+KI coating impaired S. aureus proliferation, which anticipates its potential benefit for preventing pathogenic bacterial complications associated with prosthetic crown placement.

Mild periconceptional hyperglycemia: predictor of adverse fetomaternal outcomes in gestational diabetes?

AIM

To clarify whether mild first trimester hyperglycaemia (characteristic of early-onset GDM) is associated with higher incidence of congenital malformations and other adverse fetomaternal outcomes compared to women with second trimester hyperglycaemia (later-onset GDM).

DESIGN AND METHODS

We analyzed the Portuguese National GDM database, containing data collected between 2011 and 2017. Two study groups were defined: Group 1-Women with GDM diagnosed during the first trimester (with fasting glycemia ≥ 92 and < 126 mg/dL); Group 2-Women with GDM diagnosed after the first 12 weeks of gestation, with either fasting glycemia or oral glucose tolerance test, according to the International Association of Pregnancy and Diabetes Study Group criteria. The fetomaternal characteristics of each group were compared.

RESULTS

A total of 18.518 pregnant women diagnosed with GDM were included which 34.4% of them belonged to Group 1. Pregnant women from this group were significantly younger and had a higher median BMI than the women from the other group. Overall, there was no significant differences in maternal morbidity parameters between groups. Non-evolutive pregnancies were significantly more frequent along the present gestation in the group 1 (1.1% vs. 0.1%, p < 0.001), as was fetal death (0.6% vs. 0.2%, p < 0.001). Congenital malformations did not differ significantly between groups (3.2% vs. 2.8%, p = 0.155).

CONCLUSIONS

The mild near conceptional hyperglycaemic state characteristic of an early-onset GDM seems to be associated with an increased prevalence of non-evolutive pregnancies and foetal deaths when compared to later-onset GDM.

The MAPKinase Signaling and the Stimulatory Protein-1 (Sp1) Transcription Factor Are Involved in the Phototherapy Effect on Cytokines Secretion from Human Bronchial Epithelial Cells Stimulated with Cigarette Smoke Extract

The present study was aimed to investigate the phototherapy effect with low-level laser on human bronchial epithelial cells activated by cigarette smoke extract (CSE). Phototherapy has been reported to actuate positively for controlling the generation/release of anti-inflammatory and pro-inflammatory mediators from different cellular type activated by distinct stimuli. It is not known whether the IL-8 and IL-10 release from CSE-stimulated human bronchial epithelium (BEAS) cells can be influenced by phototherapy. Human bronchial epithelial cell (BEAS) line was cultured in a medium with CSE and irradiated (660 nm) at 9 J. Apoptosis index was standardized with Annexin V and the cellular viability was evaluated by MTT. IL-8, IL-10, cAMP, and NF-κB were measured by ELISA as well as the Sp1, JNK, ERK1/2, and p38MAPK. Phototherapy effect was studied in the presence of mithramycin or the inhibitors of JNK or ERK. The IL-8, cAMP, NF-κB, JNK, p38, and ERK1/2 were downregulated by phototherapy. Both the JNK and the ERK inhibitors potentiated the phototherapy effect on IL-8 as well as on cAMP secretion from BEAS. On the contrary, IL-10 and Sp1 were upregulated by phototherapy. The mithramycin blocked the phototherapy effect on IL-10. The results suggest that phototherapy has a dual effect on BEAS cells because it downregulates the IL-8 secretion by interfering with CSE-mediated signaling pathways, and oppositely upregulates the IL-10 secretion through of Sp1 transcription factor. The manuscript provides evidence that the phototherapy can interfere with MAPK signaling via cAMP in order to attenuate the IL-8 secretion from CSE-stimulated BEAS. In addition, the present study showed that phototherapy effect is driven to downregulation of the both the IL-8 and the ROS secretion and at the same time the upregulation of IL-10 secretion. Besides it, the increase of Sp-1 transcription factor was crucial for laser effect in upregulating the IL-10 secretion. The dexamethasone corticoid produces a significant inhibitory effect on IL-8 as well as ROS secretion, but on the other hand, the corticoid blocked the IL-10 secretion. Taking it into consideration, it is reasonable to suggest that the beneficial effect of laser therapy on lung diseases involves its action on unbalance between pro-inflammatory and anti-inflammatory mediators secreted by human bronchial epithelial cells through different signaling pathway.

Simulation of huntington’s disease in forensic psychiatry: Case report

Introduction

Huntington Disease (HD) is an autosomal-dominant, neurodegenerative disorder, with a progressive course, that typically involves a triad of cognitive, motor and psychiatric disorders. Its pathogenic mechanisms are not fully understood, although a faultily encoded version of the protein huntingtin—resulting from a cytosine-adenine-guanine (CAG) trinucleotide expansion in the HTT gene—has been shown to cause intracellular toxicity in neural tissue. Patients usually presents with prodromic psychiatric perturbances, such as depression, delusions or personality changes. Occasionally HD gives rise to criminal behavior.

Objectives

To understand HD clinical presentation and underlines the differencial diagnosis. We present a case of a 31-year-old male offender, whose mother was diagnosed with HD, and during his forensic-psychiatric evaluation, HD was considered, but not confirmed.

Methods

Case report.

Results

A 31-year-old male offender was under a forensic-psychiatric evaluation due to a crime of domestic violence, after he discovers that his wife had an affair. He reports previous personality changes and depression, and compares himself with his mother, stating she was diagnosed with HD due to psychiatric prodromic disturbances. He shows concern about having a disease, and was waiting for genetic test result. After a clinical evaluation, and despite a family history of HD and genetic suspicion, it was important to consider differential diagnosis. The case refers to a passionate crime, which attempted to simulate a HD, considering his genetic background.

Conclusions

Psychometrically identifiable features in HD appear to be important in the context of analyzing circumstances occasioning criminal acts, but the medical history is the most important part of the examination.

Disclosure

No significant relationships.

Integrated efforts to promote mental health care during the SARS-CoV-2 pandemic: Reflecting on the experience of a university helpline

Introduction

The SARS-CoV-2 pandemic is affecting numerous dimensions of our society since the beginning of the outbreak. A significant increase in emotional distress was expected in the general population, particularly among the high-risk groups such as the oldest, chronic patients, healthcare professionals, and psychopathology vulnerable people. There was an urgent need to adapt and create solutions to promote mental health. Given the recommendations to minimize face-to-face interactions, several helplines were widely developed.

Objectives

In this work, we aim to reflect on the experience of a university helpline, that integrated efforts with the regional mental health care services.

Methods

A University helpline was created to give support to the regional community outside academia. The team was created on an online teamwork platform, to communicate through the chat, carry videoconference meetings, and store useful files. A Manchester screening decision tree was adopted, to define a set of guidelines to provide support to the callers, based mainly on the guidelines defined by the Order of Portuguese Psychologists. Liaison with the mental health care services, including other specific helplines, was established.

Results

Notwithstanding all the efforts, the number of received calls was scarce, similarly to helplines created by other national universities and by other entities.

Conclusions

A new approach to psychological intervention in crisis is needed, maintaining integrated efforts, and taking advantage of the opportunity to foster personalized mental health care in the digital era. It is important to continuously assess the value of integrated efforts in patient care and to the healthcare system.

Tribological performance of the pair human teeth vs 3D printed zirconia: An in vitro chewing simulation study

This study aims to evaluate the tribological performance of the pair human teeth/robocasted zirconia, with a special focus on the enamel wear mechanisms. Zirconia pieces produced by robocasting (RC) and unidirectional compression (UC) were compared in terms of crystalline structure, density, porosity, hardness and toughness. Chewing simulation tests were performed against human dental cusps. The cusps wear was quantified and the wear mechanisms identified. Although most of the properties of UC and RC samples are similar, differences were observed for surface roughness and porosity. Although the samples did not suffer wear, the antagonist cusps worn in a similar way. In conclusion, robocasting seems a promising technique to produce customized zirconia dental pieces, namely in what concerns the overall tribological behaviour.

Continuing Education in Health: interprofessional practices in the field of Collective Health

Family Health Support Centres (NASFs, in Portuguese) aim to develop interprofessional practices anchored in the assumptions of Primary Health Care, guided by the criteria of shared care specific professional interventions, management processes, interdisciplinarity, intersectoriality, Continuing Education in Health and health promotion. This health management methodology (Matrix Support) still represents a challenge to workers and managers, as it switches the logic of clinical thought from individual-centred, ambulatory and disciplinary care to collective, territory and interdisciplinary care. This study might illustrate and allow sharing of experiences about a work management format for multidisciplinary teams in Primary Health Care. A partnership between the University and the state health department was established in order to elaborate a collaborative, educational and supportive action. We formed a group of workers in the target area (24 municipalities and 18 teams) who had a focus on Continuing Education in Health using Institutional Analysis as theoretical reference. The main goal of the action was to provide spaces to share experiences and learning in the perspective of Continuing Education in Health. How does Continuing Education in Health support interprofessional practices in the field of Collective Health? Among the main results, we list: reflection about organisation practices of multiprofessional work, reflection about care practices and clinic management in the technical-assistance and pedagogic perspectives of Matrix Support; encouragement to improve the services offered in this level of care and their relationship with other points of the network. This experience showed us the importance of three main aspects: Continuing Education in Health, as a strategy of critical analysis about work and workers; the partnership and integration between teaching and service; and interprofessional formation processes (necessary to NASF and Collective Health).

Key messages

Continuing Education in Health is a strategy to deal with challenges and possibilities of interprofessional practices in the field of Collective Health. Enabling experiences and providing spaces for health professionals to share experience and learning.

Suitability of 3D printed pieces of nanocrystalline zirconia for dental applications

OBJECTIVES

The main goal of this work is to evaluate the suitability of nanostructured zirconia pieces obtained by robocasting additive manufacturing (AM), for dental applications.

METHODS

The density, crystalline structure, morphology/porosity, surface roughness, hardness, toughness, wettability and biocompatibility of the produced samples were compared with those of samples obtained by conventional subtractive manufacturing (SM) of a similar commercial zirconia material. Chewing simulation studies were carried out against dental human cusps in artificial saliva. The wear of the material was quantified and the wear mechanisms investigated, as well as the influence of glaze coating.

RESULTS

AM samples, that revealed to be biocompatible, are slightly less dense and more porous than SM samples, showing lower hardness, toughness and wettability than SM samples. After chewing tests, no wear was found both on AM and SM samples. However, the dental wear was significantly lower when AM samples were used as counterbody. Concerning the glazed samples, both coated surfaces and dental cusps suffered wear, being the cusps' wear higher than that found for unglazed samples. More, cusps tested against AM coated samples suffered less wear comparatively to those opposed to SM coated samples.

SIGNIFICANCE

Overall, the results presented in this paper show that AM processed nanostructured zirconia can be used in dental restorations, with important advantages from the point of view of processing and tribological performance. Moreover, the option for glaze finishing should be carefully considered both in SM and AM processed specimens.

Health literacy and physical activity as buffers to counter act work related stress

Background

Stress health problems affect 47.8% of the work force in Portugal. It is predicted that, in the next decade, these problems will overcome musculoskeletal disorders, the first cause of employee’s withdrawal from work. Research indicates connections between stress and dimensions of the work place (like job satisfaction). Nevertheless the conceptual understanding of these relationships is sparse. In order to better understand these relationships, this research focus on the use of job–specific models of stress, associating them with health literacy (HL) - in the context of the European Health Literacy Survey framework (HLS-EU) - and physical exercise.

Methods

A total of 748 participants from the different offices of a company in the financial sector (Portugal, main land and autonomous territories) participated in a cross sectional survey (CAWI). Age ranged from 25 to 65 years and HL was measured using the HLS-EU instrument validated to Portuguese (HLS-EU-PT). Each participant was allocated to one of the groups, either of satisfactory HL (when scores ≥30) or insufficient HL (when scores &lt;30).

Results

Out of the 748 participants (58.7% males, average age of 39 years), 80.4% sometimes and very often experience stress and tension in the workplace. Less than one in every two (44.4%) practice physical activity several times a week. Of the participants, 7.1% have inadequate, 39.0% problematic, 36.6% sufficient and 17.3% excellent HL (HLS-EU-PT). Employees that are more active are those who experience lower levels of stress.

Conclusions

The research of the effects of HL combined with physical exercise, as buffer variables to problems related to the effects of work stress, is a new area of research that may help understand patterns of adherence to activities that can help workers deal with everyday working conditions. More research is needed to integrate HL strategies in the work place.

Key messages

Stress health problems affect 47.8% of the work force in Portugal. Employees that are more active are those who experience lower levels of stress.

Synthesis of thermoelectric magnesium-silicide pastes for 3D printing, electrospinning and low-pressure spray

In this work, eco-friendly magnesium-silicide (Mg₂Si) semiconducting (n-type) thermoelectric pastes for building components concerning energy-harvesting devices through 3D printing, spray and electrospinning were synthetized and tested for the first time. The Mg₂Si fine powders were obtained through the combination of ball milling and thermal annealing under Ar atmosphere. While the latter process was crucial for obtaining the desired Mg₂Si phase, the ball milling was indispensable for homogenizing and reducing the grain size of the powders. The synthetized Mg₂Si powders exhibited a large Seebeck coefficient of ~ 487 µV/K and were blended with a polymeric solution in different mass ratios to adjust the paste viscosity to the different requirements of 3D printing, electrospinning and low-pressure spray. The materials produced in every single stage of the paste synthesis were characterized by a variety of techniques that unequivocally prove their viability for producing thermoelectric parts and components. These can certainly trigger further research and development in green thermoelectric generators (TEGs) capable of adopting any form or shape with enhanced thermoelectric properties. These green TEGs are meant to compete with common toxic materials such as Bi₂Te₃, PbTe and CoSb that have Seebeck coefficients in the range of ~ 290-700 μV/K, similar to that of the produced Mg₂Si powders and lower than that of 3D printed bulk Mg₂Si pieces, measured to be ~ 4866 μV/K. Also, their measured thermal conductivities proved to be significantly lower (~ 0.2 W/mK) than that reported for Mg₂Si (≥ 4 W/mK). However, it is herein demonstrated that such thermoelectric properties are not stable over time. Pressureless sintering proved to be indispensable, but difficultly achievable by long thermal annealing (even above 32 h) in inert atmosphere at 400 °C, at least for bulk Mg₂Si pieces constituted by a mean grain size of 2-3 μm. Hence, for overcoming this sintering challenge and become the silicide's extrusion viable in the production of bulk thermoelectric parts, alternative pressureless sintering methods will have to be further explored.

Characterization of CCDC103 expression profiles: further insights in primary ciliary dyskinesia and in human reproduction

PROPOSE

To study CCDC103 expression profiles and understand how pathogenic variants in CCDC103 affect its expression profile at mRNA and protein level.

METHODS

To increase the knowledge about the CCDC103, we attempted genotype-phenotype correlations in two patients carrying novel homozygous (missense and frameshift) CCDC103 variants. Whole-exome sequencing, quantitative PCR, Western blot, electron microscopy, immunohistochemistry, immunocytochemistry, and immunogold labelling were performed to characterize CCDC103 expression profiles in reproductive and somatic cells.

RESULTS

Our data demonstrate that pathogenic variants in CCDC103 gene negatively affect gene and protein expression in both patients who presented absence of DA on their axonemes. Further, we firstly report that CCDC103 is expressed at different levels in reproductive tissues and somatic cells and described that CCDC103 protein forms oligomers with tissue-specific sizes, which suggests that CCDC103 possibly undergoes post-translational modifications. Moreover, we reported that CCDC103 was restricted to the midpiece of sperm and is present at the cytoplasm of the other cells.

CONCLUSIONS

Overall, our data support the CCDC103 involvement in PCD and suggest that CCDC103 may have different assemblies and roles in cilia and sperm flagella biology that are still unexplored.

1-Deoxysphingolipids

Sphingolipids (SLs) are fundamental components of eukaryotic cells. 1-Deoxysphingolipids differ structurally from canonical SLs as they lack the essential C1-OH group. Consequently, 1-deoxysphingolipids cannot be converted to complex sphingolipids and are not degraded over the canonical catabolic pathways. Pathologically elevated 1-deoxySLs are involved in several disease conditions. Within this review, we will provide an up-to-date overview on the metabolic, physiological and pathophysiological aspects of this enigmatic class of "headless" sphingolipids.