Psychosis in Alzheimer's disease is associated with specific changes in brain MRI volume, cognition and neuropathology

Psychosis in Alzheimer's Disease (AD) is prevalent and indicates poor prognosis. However, the neuropathological, cognitive and brain atrophy patterns underlying these symptoms have not been fully elucidated. In this study, we evaluated 178 patients with AD neuropathological change (ADNC) and ante-mortem volumetric brain magnetic resonance imaging (MRI). Presence of psychosis was determined using the Neuropsychiatric Inventory Questionnaire. Clinical Dementia Rating Sum-of-boxes (CDR-SB) was longitudinally compared between groups with a follow-up of 3000 days using mixed-effects multiple linear regression. Neuropsychological tests closest to the time of MRI and brain regional volumes were cross-sectionally compared. Psychosis was associated with lower age of death, higher longitudinal CDR-SB scores, multi-domain cognitive deficits, higher neuritic plaque severity, Braak stage, Lewy Body pathology (LB) and right temporal lobe regional atrophy. Division according to the presence of LB showed differential patterns of AD-typical pathology, cognitive deficits and regional atrophy. In conclusion, psychosis in ADNC with and without LB has clinical value and associates with subgroup patterns of neuropathology, cognition and regional atrophy.

Differential atrophy along the longitudinal hippocampal axis in Alzheimer's disease for the Alzheimer's Disease Neuroimaging Initiative

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that primarily affects the hippocampus. Since hippocampal studies have highlighted a differential subregional regulation along its longitudinal axis, a more detailed analysis addressing subregional changes along the longitudinal hippocampal axis has the potential to provide new relevant biomarkers. This study included structural brain MRI data of 583 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Cognitively normal (CN) subjects, mild cognitively impaired (MCI) subjects and AD patients were conveniently selected considering the age and sex match between clinical groups. Structural MRI acquisitions were pre-processed and analysed with a new longitudinal axis segmentation method, dividing the hippocampus in three subdivisions (anterior, intermediate, and posterior). When normalizing the volume of hippocampal sub-divisions to total hippocampus, the posterior hippocampus negatively correlates with age only in CN subjects (r = -.31). The longitudinal ratio of hippocampal atrophy (anterior sub-division divided by the posterior one) shows a significant increase with age only in CN (r = .25). Overall, in AD, the posterior hippocampus is predominantly atrophied early on. Consequently, the anterior/posterior hippocampal ratio is an AD differentiating metric at early disease stages with potential for diagnostic and prognostic applications.

Redox Regulation of LAT Enhances T Cell-Mediated Inflammation

The positional cloning of single nucleotide polymorphisms (SNPs) of the neutrophil cytosolic factor 1 (Ncf1) gene, advocating that a low oxidative burst drives autoimmune disease, demands an understanding of the underlying molecular causes. A cellular target could be T cells, which have been shown to be regulated by reactive oxygen species (ROS). However, the pathways by which ROS mediate T cell signaling remain unclear. The adaptor molecule linker for activation of T cells (LAT) is essential for coupling T cell receptor-mediated antigen recognition to downstream responses, and it contains several cysteine residues that have previously been suggested to be involved in redox regulation. To address the possibility that ROS regulate T cell-dependent inflammation through LAT, we established a mouse strain with cysteine-to-serine mutations at positions 120 and 172 (LATSS). We found that redox regulation of LAT through C120 and C172 mediate its localization and phosphorylation. LATSS mice had reduced numbers of double-positive thymocytes and naïve peripheral T cells. Importantly, redox insensitivity of LAT enhanced T cell-dependent autoimmune inflammation in collagen-induced arthritis (CIA), a mouse model of rheumatoid arthritis (RA). This effect was reversed on an NCF1-mutated (NCF1m1j), ROS-deficient, background. Overall, our data show that LAT is redox-regulated, acts to repress T cell activation, and is targeted by ROS induced by NCF1 in antigen-presenting cells (APCs).

HR/MS-based lipidome analysis of rat brain modulated by tolcapone

Lipids play key roles in the body, influencing cellular regulation, function, and signalling. Tolcapone, a potent catechol-O-methyltransferase (COMT) inhibitor described to enhance cognitive performance in healthy subjects, was previously shown to impact fatty acid β-oxidation and oxidative phosphorylation. However, its impact on the brain lipidome remains unexplored. Hence, this study aimed to assess how tolcapone affects the lipidome of the rat pre-frontal cortex (PFC), a region of the brain highly relevant to tolcapone therapeutic effect, while evaluating its influence on operant behaviour. Tolcapone at 20 mg/kg was chronically administered to Wistar rats during a behavioural task and an untargeted liquid chromatography high-resolution mass spectrometry (LC-HR/MS) approach was employed to profile lipid species. The untargeted analysis identified 7227 features, of which only 33% underwent statistical analysis following data pre-processing. The results revealed an improved cognitive performance and a lipidome remodelling promoted by tolcapone. The lipidomic analysis showed 32 differentially expressed lipid species in tolcapone-treated animals (FC ≥ 1.2, p-value ≤ 0.1), and among these several triacylglycerols, cardiolipins and N-acylethanolamine (NAE 16:2) were found upregulated whereas fatty acids, hexosylceramides, and several phospholipids including phosphatidylcholines and phosphatidylethanolamines were downregulated. These preliminary findings shed light on tolcapone impact on lipid pathways within the brain. Although tolcapone improved cognitive performance and literature suggests the significance of lipids in cognition, this study did not conclusively establish that lipids directly drove or contributed to this outcome. Nevertheless, it underscores the importance of lipid modulation and encourages further exploration of tolcapone-associated mechanisms in the central nervous system (CNS).

One-year regional brain volume changes as potential predictors of cognitive function in multiple sclerosis: a pilot study

BACKGROUND

The most reliable magnetic resonance imaging (MRI) marker of cognitive dysfunction in multiple sclerosis (MS) is brain atrophy. However, 1-year volumetric changes prior to cognitive assessment were never studied as potential predictors of cognition, which we aim to assess with this pilot work.

METHODS

Twenty-two MS patients were submitted to a baseline measure of 83 regional brain volumes with MRI and re-evaluated 1 year later; they were also tested with the Brief International Cognitive Assessment for MS (BICAMS): sustained attention and processing speed were examined with the Symbol Digit Modalities Test (SDMT), verbal and visuo-spatial learning and memory with the learning trials from the California Verbal Learning Test-II (CVLT) and the Brief Visuo-spatial Memory Test-revised (BVMT), respectively. Controlling for age, sex, and years of education, a multivariate linear regression model was created for each cognitive score at 1-year follow-up in a backward elimination manner, considering cross-sectional regional volumes and 1-year volume changes as potential predictors.

RESULTS

Decreases in the volumes of the left amygdala and the right lateral orbitofrontal cortex in the year prior to assessment were identified as possible predictors of worse performance in verbal memory (P = 0.009) and visuo-spatial memory (P = 0.001), respectively, independently of cross-sectional brain regional volumes at time of testing.

CONCLUSION

Our work reveals novel 1-year regional brain volume changes as potential predictors of cognitive deficits in MS. This suggests a possible role of these regions in such deficits and might contribute to uncover cognitively deteriorating patients, whose detection is still unsatisfying in clinical practice.

Comparison of in-office and at-home bleaching techniques: An umbrella review of efficacy and post-operative sensitivity

Objectives

The objective of this umbrella review is to evaluate the efficacy and adverse effects of different teeth whitening techniques in-office (IO) and at-home (AH), regarding chromatic changes and teeth sensitivity.

Materials and methods

The search was carried out from several databases. The included studies were all systematic reviews with or without meta-analysis of RCT or quasi-RCT. The participants were patients that underwent external dental bleaching in permanent vital teeth. The interventions were in-office (IO) bleaching techniques and at-home (AT) bleaching techniques with different bleaching agents and concentrations.

Results

The search resulted in a total of 257 articles, and 28 SR were included in the qualitative analysis and nine in the quantitative analysis. There is no difference between in-office and at-home techniques in terms of color change (p = 0.95) and post-treatment sensitivity (p = 0.85). There is similarity risk and intensity of teeth sensitivity between AH and IO bleaching. IO bleaching with light-activated systems with low concentrations of bleaching agent showed similar results to IO bleaching techniques with high concentrated bleaching gels. With the application of the criteria of the AMSTAR 2 tool, the reviews were considered critically low to high.

Conclusions

There are no significant differences in terms of color change between the different bleaching techniques compared. Teeth sensitivity is always present regardless of the technique used. The use of light activation systems did not increase the intensity and risk of post-operative sensitivity.

White matter diffusion estimates in obsessive-compulsive disorder across 1653 individuals: machine learning findings from the ENIGMA OCD Working Group

White matter pathways, typically studied with diffusion tensor imaging (DTI), have been implicated in the neurobiology of obsessive-compulsive disorder (OCD). However, due to limited sample sizes and the predominance of single-site studies, the generalizability of OCD classification based on diffusion white matter estimates remains unclear. Here, we tested classification accuracy using the largest OCD DTI dataset to date, involving 1336 adult participants (690 OCD patients and 646 healthy controls) and 317 pediatric participants (175 OCD patients and 142 healthy controls) from 18 international sites within the ENIGMA OCD Working Group. We used an automatic machine learning pipeline (with feature engineering and selection, and model optimization) and examined the cross-site generalizability of the OCD classification models using leave-one-site-out cross-validation. Our models showed low-to-moderate accuracy in classifying (1) "OCD vs. healthy controls" (Adults, receiver operator characteristic-area under the curve = 57.19 ± 3.47 in the replication set; Children, 59.8 ± 7.39), (2) "unmedicated OCD vs. healthy controls" (Adults, 62.67 ± 3.84; Children, 48.51 ± 10.14), and (3) "medicated OCD vs. unmedicated OCD" (Adults, 76.72 ± 3.97; Children, 72.45 ± 8.87). There was significant site variability in model performance (cross-validated ROC AUC ranges 51.6-79.1 in adults; 35.9-63.2 in children). Machine learning interpretation showed that diffusivity measures of the corpus callosum, internal capsule, and posterior thalamic radiation contributed to the classification of OCD from HC. The classification performance appeared greater than the model trained on grey matter morphometry in the prior ENIGMA OCD study (our study includes subsamples from the morphometry study). Taken together, this study points to the meaningful multivariate patterns of white matter features relevant to the neurobiology of OCD, but with low-to-moderate classification accuracy. The OCD classification performance may be constrained by site variability and medication effects on the white matter integrity, indicating room for improvement for future research.

Noradrenergic Pathways Involved in Micturition in an Animal Model of Hydrocephalus-Implications for Urinary Dysfunction

Hydrocephalus is characterized by enlargement of the cerebral ventricles, accompanied by distortion of the periventricular tissue. Patients with hydrocephalus usually experience urinary impairments. Although the underlying etiology is not fully described, the effects of hydrocephalus in the neuronal network responsible for the control of urination, which involves periventricular areas, including the periaqueductal gray (PAG) and the noradrenergic locus coeruleus (LC). In this study, we aimed to investigate the mechanisms behind urinary dysfunction in rats with kaolin-induced hydrocephalus. For that purpose, we used a validated model of hydrocephalus-the rat injected with kaolin in the cisterna magna-also presents urinary impairments in order to investigate the putative involvement of noradrenergic control from the brain to the spinal cord Onuf's nucleus, a key area in the motor control of micturition. We first evaluated bladder contraction capacity using cystometry. Since our previous characterization of the LC in hydrocephalic animals showed increased levels of noradrenaline, we then evaluated the noradrenergic innervation of the spinal cord's Onuf's nucleus by measuring levels of dopamine β-hydroxylase (DBH). We also evaluated the expression of the c-Fos protooncogene, the most widely used marker of neuronal activation, in the ventrolateral PAG (vlPAG), an area that plays a major role in the control of urination by its indirect control of the LC via pontine micturition center. Hydrocephalic rats showed an increased frequency of bladder contractions and lower minimum pressure. These animals also presented increased DBH levels at the Onuf´s nucleus, along with decreased c-Fos expression in the vlPAG. The present findings suggest that impairments in urinary function during hydrocephalus may be due to alterations in descending noradrenergic modulation. We propose that the effects of hydrocephalus in the decrease of vlPAG neuronal activation lead to a decrease in the control over the LC. The increased availability of noradrenaline production at the LC probably causes an exaggerated micturition reflex due to the increased innervation of the Onuf´s nucleus, accounting for the urinary impairments detected in hydrocephalic animals. The results of the study provide new insights into the neuronal underlying mechanisms of urinary dysfunction in hydrocephalus. Further research is needed to fully evaluate the translational perspectives of the current findings.

[Translated article] Risk factors for infection of tibial plateau fractures

INTRODUCTION

Tibial plateau fractures are injuries prone to postoperative infection, with its reported incidence being higher than that of other fractures, between 5% and 12%. The primary objectives of this study were to quantify the postoperative infection rate of internal fixation of tibial plateau fractures (TPFs) and to identify the risk factors for this.

MATERIAL AND METHODS

Retrospective cohort study including patients who underwent TPF osteosynthesis between 2015 and 2020, in the same center. The study population was divided into two groups, according to the presence or absence of postoperative infection. Demographic variables related to the fracture, surgical parameters, as well as the need for reoperation were collected. Finally, in the case of debridement, the number of positive cultures and the pathogen responsible for the infection were collected, as well as the treatment applied.

RESULTS

One hundred and twenty-four patients were included, with a total of 14 infections (global infection rate of 11.3%). Risk factors for developing infection were open fractures (p=.002), Schatzker V and VI type fractures (p=.002) and the use of external fixation (p<.001). Regarding the surgical variables, only the longest ischemia time (p=.032) was identified as a risk factor. Staphylococcus aureus was the most frequently identified microorganism (43%), followed by Enterobacter cloacae (35.7%).

CONCLUSION

The overall infection rate after osteosynthesis of tibial plateau fractures was 11.3%. Different factors are associated with a higher risk of infection, including diabetes mellitus, open fractures, the use of external fixation, a higher grade in the Schatzker classification or a longer intraoperative ischemia time.

Risk factors for infection of tibial plateau fractures

INTRODUCTION

Tibial plateau fractures are injuries prone to postoperative infection, with its reported incidence being higher than that of other fractures, between 5% and 12%. The primary objectives of this study were to quantify the postoperative infection rate of internal fixation of tibial plateau fractures (TPF) and to identify the risk factors for this.

MATERIAL AND METHODS

Retrospective cohort study including patients who underwent TPF osteosynthesis between 2015 and 2020, in the same center. The study population was divided into two groups, according to the presence or absence of postoperative infection. Demographic variables related to the fracture, surgical parameters, as well as the need for reoperation were collected. Finally, in the case of debridement, the number of positive cultures and the pathogen responsible for the infection were collected, as well as the treatment applied.

RESULTS

One hundred and twenty-four patients were included, with a total of 14 infections (global infection rate of 11.3%). Risk factors for developing infection were open fractures (P=.002), Schatzker V and VI type fractures (P=.002) and the use of external fixation (P<.001). Regarding the surgical variables, only the longest ischemia time (P=.032) was identified as a risk factor. S. aureus was the most frequently identified microorganism (43%), followed by E. cloacae (35.7%).

CONCLUSION

The overall infection rate after osteosynthesis of tibial plateau fractures was 11.3%. Different factors are associated with a higher risk of infection, including diabetes mellitus, open fractures, the use of external fixation, a higher grade in the Schatzker classification or a longer intraoperative ischemia time.

Antigen-presenting autoreactive B cells activate regulatory T cells and suppress autoimmune arthritis in mice

B cells undergo several rounds of selection to eliminate potentially pathogenic autoreactive clones, but in contrast to T cells, evidence of positive selection of autoreactive B cells remains moot. Using unique tetramers, we traced natural autoreactive B cells (C1-B) specific for a defined triple-helical epitope on collagen type-II (COL2), constituting a sizeable fraction of the physiological B cell repertoire in mice, rats, and humans. Adoptive transfer of C1-B suppressed arthritis independently of IL10, separating them from IL10-secreting regulatory B cells. Single-cell sequencing revealed an antigen processing and presentation signature, including induced expression of CD72 and CCR7 as surface markers. C1-B presented COL2 to T cells and induced the expansion of regulatory T cells in a contact-dependent manner. CD72 blockade impeded this effect suggesting a new downstream suppressor mechanism that regulates antigen-specific T cell tolerization. Thus, our results indicate that autoreactive antigen-specific naïve B cells tolerize infiltrating T cells against self-antigens to impede the development of tissue-specific autoimmune inflammation.

Genome-wide identification of core components of ABA signaling and transcriptome analysis reveals gene circuits involved in castor bean (Ricinus communis L.) response to drought

Castor bean (Ricinus communis L.) can withstand long periods of water deficit and high temperatures, and therefore has been recognized as a drought-resistant plant species, allowing the study of gene networks involved in drought response and tolerance. The identification of genes networks related to drought response in this plant may yield important information in the characterization of molecular mechanisms correlating changes in the gene expression with the physiological adaptation processes. In this context, gene families related to abscisic acid (ABA) signaling play a crucial role in developmental and environmental adaptation processes of plants to drought stress. However, the families that function as the core components of ABA signaling, as well as genes networks related to drought response, are not well understood in castor bean. In this study 7 RcPYL, 63 RcPP2C, and 6 RcSnRK2 genes were identified in castor bean genome, which was further supported by chromosomal distribution, gene structure, evolutionary relationships, and conserved motif analyses. The castor bean general expression profile was investigated by RNAseq in root and leaf tissues in response to drought stress. These analyses allowed the identification of genes differentially expressed, including genes from the ABA signaling core, genes related to photosynthesis, cell wall, energy transduction, antioxidant response, and transcription factors. These analyses provide new insights into the core components of ABA signaling in castor bean, allow the identification of several molecular responses associated with the high physiological adaptation of castor bean to drought stress, and contribute to the identification of candidate genes for genetic improvement.

Tuberculosis medicines for children in Europe: an unmet medical need

The availability of first-line medicines for the treatment of drug-susceptible tuberculosis (TB) is inconsistent across European countries. This is particularly worrisome for child-friendly medicines. There are reported examples of physicians being forced to adapt and/or combine formulations intended for adults to treat children with TB. Reduced compliance, unknown effects on treatment outcomes and unpredictable toxicity are potential consequences of resorting to these suboptimal treatment options. Furthermore, the use of these alternatives may increase the risk of drug-resistant TB. This study analysed the availability and use of TB medicines in the European Union (EU)/European Economic Area, with a particular focus on child-friendly formulations. We sought to carry out a full review of the situation by means of a survey involving the EU regulatory network. Countries were asked to confirm marketing status of anti-drug-susceptible-TB medicines, ways used to overcome their absence in their territory and the general difficulties they face to treat children with TB. Results confirmed that rifampicin suspension is the only child-friendly formulation available in Europe, approved in just 10 member states. Overall, 24 countries out of 30 considered the lack of adequate drug-susceptible TB medicines an unmet medical need. To overcome this, countries confirmed that they resort to importation or use adapted formulations. The joint forces of European institutions and pharmaceutical industry are crucial for the development of paediatric formulations and contribute to better compliance and health outcomes.

Coffee consumption decreases the connectivity of the posterior Default Mode Network (DMN) at rest

Habitual coffee consumers justify their life choices by arguing that they become more alert and increase motor and cognitive performance and efficiency; however, these subjective impressions still do not have a neurobiological correlation. Using functional connectivity approaches to study resting-state fMRI data in a group of habitual coffee drinkers, we herein show that coffee consumption decreased connectivity of the posterior default mode network (DMN) and between the somatosensory/motor networks and the prefrontal cortex, while the connectivity in nodes of the higher visual and the right executive control network (RECN) is increased after drinking coffee; data also show that caffeine intake only replicated the impact of coffee on the posterior DMN, thus disentangling the neurochemical effects of caffeine from the experience of having a coffee.

Bulk-Fill Resins versus Conventional Resins: An Umbrella Review

Currently, composite resins have become the material of choice for the restoration of posterior teeth. Although bulk-fill resins represent a tempting alternative due to their lower complexity and faster use, some dentists are reluctant to use this material. The objective is to compare the performance of bulk-fill resins and conventional resins in direct restorations of posterior teeth based on the literature. The databases that were used to carry out the research were PubMed/MEDLINE, Embase, the Cochrane Library and the WOS. This umbrella literature review complies with PRISMA standards and assesses the quality of studies using the AMSTAR 2 tool. With the application of the criteria of the AMSTAR 2 tool, the reviews were considered low to moderate. The overall meta-analysis, although without statistical significance, favours mostly the use of conventional resin, as it is about five times more likely to obtain a favourable result than bulk-fill resin. Bulk-fill resins result in a simplification of the clinical process of posterior direct restorations, which is an advantage. The performance in terms of several properties of bulk-fill resins and conventional resins showed that they present similar behaviour.

Perceived stress modulates the activity between the amygdala and the cortex

The significant link between stress and psychiatric disorders has prompted research on stress's impact on the brain. Interestingly, previous studies on healthy subjects have demonstrated an association between perceived stress and amygdala volume, although the mechanisms by which perceived stress can affect brain function remain unknown. To better understand what this association entails at a functional level, herein, we explore the association of perceived stress, measured by the PSS10 questionnaire, with disseminated functional connectivity between brain areas. Using resting-state fMRI from 252 healthy subjects spanning a broad age range, we performed both a seed-based amygdala connectivity analysis (static connectivity, with spatial resolution but no temporal definition) and a whole-brain data-driven approach to detect altered patterns of phase interactions between brain areas (dynamic connectivity with spatiotemporal information). Results show that increased perceived stress is directly associated with increased amygdala connectivity with frontal cortical regions, which is driven by a reduced occurrence of an activity pattern where the signals in the amygdala and the hippocampus evolve in opposite directions with respect to the rest of the brain. Overall, these results not only reinforce the pathological effect of in-phase synchronicity between subcortical and cortical brain areas but also demonstrate the protective effect of counterbalanced (i.e., phase-shifted) activity between brain subsystems, which are otherwise missed with correlation-based functional connectivity analysis.

Evaluation of the Sealing Ability and Bond Strength of Two Endodontic Root Canal Sealers: An In Vitro Study

BACKGROUND

Obturation represents a critical step in endodontic treatment, which relies on a core material and a sealer. This study aims to evaluate the sealing ability and bond strength to the root canal walls of an epoxy resin-based sealer (AH-Plus®, Dentsply Sirona, Johnson City, TN, USA) and a bioceramic sealer (GuttaFlow Bioseal®, Coltène/Whaledent, GmbH + Co. KG, Langenau, Germany).

METHODS

Thirty-eight maxillary anterior teeth with single roots and identical round sections were separated into two experimental groups according to the root canal sealers used, namely, G1 = AH-Plus® and G2 = GuttaFlow Bioseal®, and two control groups, specifically, G3 = the negative control and G4 = the positive control. The sealing capacity was measured by the penetration of the radioactive isotope 99mTc. For the push-out test, the compressive force test was performed in a universal machine and the force was applied by exerting pressure on the surface of the material to be tested in the apical to the coronal direction and using three test points with different diameters.

RESULTS

GuttaFlow Bioseal® exhibited superior sealing ability compared to AH-Plus® (p = 0.003). Regarding the bond strength, AH-Plus® provided higher adhesion values than GuttaFlow Bioseal® in the three sections of the tooth root (p = 0.001).

CONCLUSIONS

GuttaFlow Bioseal® had significantly better sealing ability than AH-Plus® but lower adhesion values in the three zones of the root canal, with statistically significant differences between the groups. However, it is important to note that for the action of endodontic sealers to be maximized, the root-filling technique must be most appropriate.

Association of amygdala size with stress perception: Findings of a transversal study across the lifespan

Daily routines are getting increasingly stressful. Interestingly, associations between stress perception and amygdala volume, a brain region implicated in emotional behaviour, have been observed in both younger and older adults. Life stress, on the other hand, has become pervasive and is no longer restricted to a specific age group or life stage. As a result, it is vital to consider stress as a continuum across the lifespan. In this study, we investigated the relationship between perceived stress and amygdala size in 272 healthy participants with a broad age range. Participants were submitted to a structural magnetic resonance imaging (MRI) to extract amygdala volume, and the Perceived Stress Scale (PSS) scores were used as the independent variable in volumetric regressions. We found that perceived stress is positively associated with the right amygdala volume throughout life.

NCF4 dependent intracellular reactive oxygen species regulate plasma cell formation

Defective reactive oxygen species (ROS) production by genetically determined variants of the NADPH oxidase 2 (NOX2) complex component, NCF4, leads to enhanced production of autoantibodies to collagen type II (COL2) and severe collagen-induced arthritis (CIA) in mice. To further understand this process, we used mice harboring a mutation in the lipid endosomal membrane binding site (R58A) of NCF4 subunit. This mutation did not affect the extracellular ROS responses but showed instead decreased intracellular responses following B cell stimulation. Immunization with COL2 led to severe arthritis with increased antibody levels in Ncf4^58A mutated animals without significant effects on antigen presentation, autoreactive T cell activation and germinal center formation. Instead, plasma cell formation was enhanced and had altered CXCR3/CXCR4 expression. This B cell intrinsic effect was further confirmed with chimeric B cell transfer experiments and in vitro LPS or CD40L with anti-IgM stimulation. We conclude that NCF4 regulates the terminal differentiation of B cells to plasma cells through intracellular ROS.

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Ncf4^R58A selectively affects intracellular ROS production after stimulation.

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Decreased intracellular ROS in B cell promotes plasma cell formation intrinsically.

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BCR stimulation induced NOX2 complex-ROS regulates CXCR3 expression on plasma cell.

Early results of a distance learning paediatric surgery programme in Mozambique

INTRODUCTION

A pre-graduate training programme in paediatric surgery was applied to students in four medical schools of Mozambique. In this paper, we evaluate the early results of the programme.

MATERIALS AND METHODS

A pre-graduate training programme was developed and applied in two stages, theoretical education available at an online platform and a face-to-face session. To evaluate the programme, a diagnostic test was applied to all participants before the face-to-face session and, the same test, was applied again at the end of the session.

RESULTS

A total of 236 students participated in the programme. Forty-four per cent had a negative score on the diagnostic test. When the test was repeated, 91.9% had a positive score, and the difference between the scores in both tests reached statistical significance (P < 0.05). The participants who completed the first phase of the programme presented a higher median score in both tests (P < 0.05).

CONCLUSIONS

: The diagnostic tests allowed us to verify there was an increase in knowledge before and after the face-to-face session. There was also a significant difference between those participants who completed the online phase of the programme and those who did only the face-to-face session, which allows us to conclude that the online teaching programme was effective.

CAMBRA Protocol Efficacy: A Systematic Review and Critical Appraisal

The Caries Management by Risk Assessment (CAMBRA) protocol consists of analyzing the patient’s profile by assessing the risk and protective factors and assigning a risk level to the patient to allow an individualized treatment plan, which combines restorative treatments with a preventive chemical therapy. This systematic review and critical appraisal aim to evaluate the effectiveness of the CAMBRA protocol in reducing the incidence of caries lesions and oral bacterial load. An electronic search was carried out in the Cochrane Library, PubMed, Web of Science, Scopus, and Embase databases. Clinical studies evaluating the incidence of dental caries lesions and/or the reduction of cariogenic bacterial load (Streptococcus mutans and/or Lactobacilli spp.), with at least an intervention group that follows the CAMBRA protocol and a control group published up until January 2022, were included. The methodological quality assessment of the included clinical studies was assessed through the Revised Cochrane risk-of-bias tool for randomized trials (RoB 2). The quality of the case-control study was evaluated according to the Methodological Index for Non-Randomized Studies (ROBINS-I). There is currently no scientific evidence to recommend the integration of the CAMBRA protocol into clinical practice. The results reported by the studies included in the systematic review do not suggest a decrease in the incidence of dental caries lesions and/or bacterial load. There is a clear need for the development of new clinical studies with an adequate methodology and follow-up, both for the CAMBRA protocol and for its components individually.

Magnetic resonance elastography of the ageing brain in normal and demented populations: A systematic review

The aim of this systematic review was to evaluate the ability of magnetic resonance elastography (MRE) to identify significant changes in brain mechanical properties during normal and pathological aging. PubMed, Web of Science and Scopus were searched for human studies using MRE to assess brain mechanical properties in cognitively healthy individuals, individuals at risk of dementia or patients diagnosed with dementia. Study characteristics, sample demographics, clinical characterization and main MRE outcomes were summarized in a table. A total of 19 studies (nine aging, 10 dementia), comprising 700 participants, were included. The main findings were decreased cerebral stiffness along aging, with rates of annual change ranging from −0.008 to −0.025 kPa per year. Also, there were regional differences in the age effect on brain stiffness. Concerning demented patients, differential patterns of stiffness were found for distinct dementia subtypes. Alzheimer's disease and frontotemporal dementia exhibited decreased brain stiffness in comparison to cognitively healthy controls and significant declines were found in regions known to be affected by the disease. In normal pressure hydrocephalus, the results were not consistent across studies, and in dementia with Lewy bodies no significant differences in brain stiffness were found. In conclusion, aging is characterized by the softening of brain tissue and this event is even more pronounced in pathological aging, such as dementia. MRE technique could be applied as a sensible diagnostic tool to identify deviations from normal aging and develop new brain biomarkers of cognitive decline/dementia that would help promote healthier cognitive aging.

A novel method for estimating connectivity-based parcellation of the human brain from diffusion MRI: Application to an aging cohort

Connectivity‐based parcellation (CBP) methods are used to define homogenous and biologically meaningful parcels or nodes—the foundations of brain network fingerprinting—by grouping voxels with similar patterns of brain connectivity. However, we still lack a gold standard method and the use of CBPs to study the aging brain remains scarce. Our study proposes a novel CBP method from diffusion MRI data and shows its potential to produce a more accurate characterization of the longitudinal alterations in brain network topology occurring in aging. For this, we constructed whole‐brain connectivity maps from diffusion MRI data of two datasets: an aging cohort evaluated at two timepoints (mean interval time: 52.8 ± 7.24 months) and a normative adult cohort—MGH‐HCP. State‐of‐the‐art clustering techniques were used to identify the best performing technique. Furthermore, we developed a new metric (connectivity homogeneity fingerprint [CHF]) to evaluate the success of the final CBP in improving regional/global structural connectivity homogeneity. Our results show that our method successfully generates highly homogeneous parcels, as described by the significantly larger CHF score of the resulting parcellation, when compared to the original. Additionally, we demonstrated that the developed parcellation provides a robust anatomical framework to assess longitudinal changes in the aging brain. Our results reveal that aging is characterized by a reorganization of the brain's structural network involving the decrease of intra‐hemispheric, increase of inter‐hemispheric connectivity, and topological rearrangement. Overall, this study proposes a new methodology to perform accurate and robust evaluations of CBP of the human brain.

The Mediating Role of Resilience and Life Satisfaction in the Relationship between Stress and Burnout in Medical Students during the COVID-19 Pandemic

Following the WHO's declaration of a public health emergency due to the COVID-19 outbreak, the subsequent quarantine and confinement measures that were adopted, including distance learning measures, were shown to have caused a significant deterioration in the mental health of medical students. The goal of this study was to explore the mediating role of resilience and life satisfaction in the relationship between perceived stress and burnout among medical students in the context of COVID-19. A transversal assessment was performed using an online questionnaire, to which 462 students responded. The instruments applied were the Perceived Stress Scale-10, the Resilience Scale-25 items, the Satisfaction with Life Scale (SWLS), and the Burnout Scale (Oldenburg Inventory). A regression model was estimated for each dimension of burnout. The results revealed that resilience and life satisfaction play a mediating role in the association between stress and the dimensions of burnout. This suggests that measures of promoting mental health based on resilience and improving perceptions of life should be implemented.

Suicidal Ideation Is Associated With Reduced Functional Connectivity and White Matter Integrity in Drug-Naïve Patients With Major Depression

Depression is a highly prevalent psychiatric disorder affecting millions of people worldwide. Depression is characterized by decreased mood or loss of interest in daily activities, changes in feeding and circadian rhythms and significant impairments in cognitive and executive function. In addition, the occurrence of recurrent thoughts of death and suicidal ideation confers depressed patients a higher risk of suicide than the general population. With this study, we aimed to explore the neural correlates of suicidal ideation in drug-naïve patients diagnosed with depression. Twenty-five patients were scanned using two-different magnetic resonance imaging (MRI) modalities, resting state functional MRI (fMRI) and diffusion tensor imaging (DTI). Resting state allowed the exploration of connectivity patterns in the absence of a specific stimulus and DTI allowed a detailed analysis of structural white matter integrity with measures like fractional anisotropy (FA). Probabilistic independent component analysis (PICA), network-based statistics and tract-based spatial statistics (TBSS) were applied to analyze resting-state fMRI and DTI data, respectively. Our results showed that, in our sample of drug-naïve patients, suicidal ideation was negatively associated with resting-state functional connectivity in the visual networks and with FA in the genu of corpus callosum and in the right anterior corona radiata. In addition, a significant association was identified between suicidal ideation and a functional connectivity network that included connections between regions in the superior and orbitofrontal cortex, the cerebellum, the cingulate gyrus as well as temporal and occipital regions. In conclusion, this work has expanded our knowledge about the possible functional and structural neuronal correlates of suicidal ideation in drug-naïve patients with depression, paving the way for future personalized therapeutic approaches.

An integrative proteomics method identifies a regulator of translation during stem cell maintenance and differentiation

Detailed characterization of cell type transitions is essential for cell biology in general and particularly for the development of stem cell-based therapies in regenerative medicine. To systematically study such transitions, we introduce a method that simultaneously measures protein expression and thermal stability changes in cells and provide the web-based visualization tool ProteoTracker. We apply our method to study differences between human pluripotent stem cells and several cell types including their parental cell line and differentiated progeny. We detect alterations of protein properties in numerous cellular pathways and components including ribosome biogenesis and demonstrate that modulation of ribosome maturation through SBDS protein can be helpful for manipulating cell stemness in vitro. Using our integrative proteomics approach and the web-based tool, we uncover a molecular basis for the uncoupling of robust transcription from parsimonious translation in stem cells and propose a method for maintaining pluripotency in vitro.

Habitual coffee drinkers display a distinct pattern of brain functional connectivity

Coffee is the most widely consumed source of caffeine worldwide, partly due to the psychoactive effects of this methylxanthine. Interestingly, the effects of its chronic consumption on the brain's intrinsic functional networks are still largely unknown. This study provides the first extended characterization of the effects of chronic coffee consumption on human brain networks. Subjects were recruited and divided into two groups: habitual coffee drinkers (CD) and non-coffee drinkers (NCD). Resting-state functional magnetic resonance imaging (fMRI) was acquired in these volunteers who were also assessed regarding stress, anxiety, and depression scores. In the neuroimaging evaluation, the CD group showed decreased functional connectivity in the somatosensory and limbic networks during resting state as assessed with independent component analysis. The CD group also showed decreased functional connectivity in a network comprising subcortical and posterior brain regions associated with somatosensory, motor, and emotional processing as assessed with network-based statistics; moreover, CD displayed longer lifetime of a functional network involving subcortical regions, the visual network and the cerebellum. Importantly, all these differences were dependent on the frequency of caffeine consumption, and were reproduced after NCD drank coffee. CD showed higher stress levels than NCD, and although no other group effects were observed in this psychological assessment, increased frequency of caffeine consumption was also associated with increased anxiety in males. In conclusion, higher consumption of coffee and caffeinated products has an impact in brain functional connectivity at rest with implications in emotionality, alertness, and readiness to action.

Effects of Adper™ Scotchbond™ 1 XT, Clearfil™ SE Bond 2 and Scotchbond™ Universal in Odontoblasts

This study aimed to assess the cytotoxicity of commercially available adhesive strategies-etch-and-rinse (Adper™ Scotchbond™ 1 XT, 3M ESPE, St. Paul, MN, USA, SB1), self-etch (Clearfil™ SE Bond 2, Kuraray Noritake Dental Inc., Tokyo, Japan, CSE), and universal (Scotchbond™ Universal, 3M Deutschland GmbH, Neuss, Germany, SBU). MDPC-23 cells were exposed to adhesives extracts in different concentrations and exposure times. To access cell metabolic activity, viability, types of cell death, and cell cycle, the MTT assay, SRB assay, double labeling with annexin V and propidium iodide, and labeling with propidium iodide/RNAse were performed, respectively. Cultures were stained with May-Grünwald Giemsa for qualitative cytotoxicity assessment. The SB1, CSE, and SBU extracts determined a significant reduction in cell metabolism and viability. This reduction was higher for prolonged exposures, even for less concentrated extracts. CSE extracts significantly reduced the cell's metabolic activity at higher concentrations (50% and 100%) from 2 h of exposure. After 24 and 96 h, a metabolic activity reduction was verified for all adhesives, even at lower concentrations. These changes were dependent on the adhesive, its concentration, and the incubation time. Regarding cell viability, SBU extracts were the least cytotoxic, and CSE was significantly more cytotoxic than SB1 and SBU. The adhesives determined a reduction in viable cells and an increase in apoptotic, late apoptosis/necrosis, and necrotic cells. Moreover, on cultures exposed to SB1 and CSE extracts, a decrease in the cells in S and G2/M phases and an increase in the cells in G0/G1 phase was observed. Exposure to SBU led to an increase of cells in the S phase. In general, all adhesives determined cytotoxicity. CSE extracts were the most cytotoxic and were classified as having a higher degree of reactivity, leading to more significant inhibition of cell growth and destruction of the cell's layers.

Pilot study on the effectiveness of Reminiscence Therapy on cognition, depressive symptoms, and quality of life in nursing home residents

Aim

This study aimed to assess the effectiveness of the group Reminiscence Therapy (RT) on cognition, depressive symptoms, and quality of life (QOL) in older adults recruited in nursing homes.

Methods

A pilot study with a one-group pretest-posttest design was conducted between September 2017 and March 2018 in five nursing homes from central Portugal. A comprehensive RT program (Core program followed by a Follow-up program) was provided to clinically stable volunteers aged 65 years or more, who did not have severe cognitive impairment.

Results

From the 50 older adults (32 women and 18 men, with mean age of 83.32±7.76, and mean education level of 5.48±4.05) considered eligible to participate in the study, 35 (mean age: 84.17±7.46, mean education level of 6.14±4.49) completed the Core Program and 28 completed the Follow-up Program (mean age: 84.25±7.66, mean education level of 6.18±4.57). Based on the Wilcoxon Test, it was observed that the participants' cognitive performance did not change during the two RT programs. No significant changes were confirmed in relation to depressive symptomatology and QOL.

Conclusion

Although no statistically significant improvements of the older adults' cognitive function, depressive symptomatology, and quality of life were found, the stabilization of such outcomes are relevant from a clinical viewpoint. Further studies are necessary to confirm these findings.

The Association of Metabolic Dysfunction and Mood Across Lifespan Interacts With the Default Mode Network Functional Connectivity

Background: Numerous studies suggest a relationship between depression and metabolic syndrome, which is likely influenced by age. Interestingly, functional imaging analysis has shown an association between functional connectivity in the default mode network (DMN-FC) and components of metabolic syndrome, which is explored in this study.

Methods: From a larger longitudinal cohort study on healthy aging, 943 individuals were extensively characterized for mood and cognition. Among these, 120 individuals who were selected for displaying extreme cognitive performance within the normal range (good and poor performers) were further studied. Here, in a cross-sectional design, using confirmatory factor analysis (CFA), the association between metabolic dysfunction and depressive mood as a function of age and its relationship with DMN-FC was studied.

Results: Metabolic dysfunction was modeled as a second-order latent variable using CFA. First-order latent variables were obesity, glucose dysmetabolism, lipids imbalance, and blood pressure. Using multiple linear regression models, this study observed that metabolic dysfunction, glucose dysmetabolism, and lipids imbalance were linearly associated with depressive mood, and the association with obesity was U-shaped. The association of metabolic dysfunction, obesity, and glucose dysmetabolism with depressive mood is positive for the younger individuals in our sample and vanishes with aging. The FC of the right superior temporal gyrus with the DMN correlated with both obesity and depressive mood. In participants with higher obesity scores, FC increased with higher GDS scores, while in those with lower GDS scores, FC decreased. Age and blood pressure were associated with a more complex pattern of association between FC of the right supramarginal gyrus and GDS score.

Conclusion: The association of metabolic dysfunction with depressive mood is influenced by age and relates with differential patterns of DMN-FC. The combination of the effects of age, mood, and metabolic dysfunction is likely to explain the heterogeneity of DMN-FC, which deserves further investigation with larger and longitudinal studies.

Aesthetic restoration of posterior teeth using different occlusal matrix techniques

The occlusal matrix technique appears as an alternative to the conventional restorative technique. The aim of this study is to present treatment options for the decayed occlusal surface of posterior teeth by means of an occlusal matrix made with different materials, for an accurate reproduction of the tooth surface. This paper presents five clinical cases using five different materials, such as Bite-Perf, flowable composite, self-curing acrylic resin, silicone and thermoforming foil. Before light-curing, the last layer of composite resin, the matrix, is repositioned and firmly pressed so the replication of the original occlusal anatomy can be achieved. When using an occlusal matrix, minimal or no finishing and polishing procedures are needed and the offered aesthetics are clearly an advantage. Moreover, this technique makes up for the additional chairside work time. The occlusal matrix technique is demonstrated to be effective for direct composite resin restorations in posterior teeth, allowing a reliable and predictable reproduction of the occlusal anatomy and clinical adjustment. For this purpose, a clear material is preferable since it allows light transmission.

White Matter Microstructure Alterations Associated With Paroxetine Treatment Response in Major Depression

More than one-third of depressive patients do not achieve remission after the first antidepressant treatment. The "watch and wait" approach used to find the most effective antidepressant leads to an increased personal, social, and economic burden in society. In order to overcome this challenge, there has been a focus on studying neural biomarkers associated with antidepressant response. Diffusion tensor imaging measures have shown a promising role as predictors of antidepressant response by pointing to pretreatment differences in the white matter microstructural integrity between future responders and non-responders to different pharmacotherapies. Therefore, the aim of the present study was to explore whether response to paroxetine treatment was associated with differences in the white matter microstructure at baseline. Twenty drug-naive patients diagnosed with major depressive disorder followed a 6- to 12-week treatment with paroxetine. All patients completed magnetic resonance brain imaging and a clinical assessment at baseline and 6-12 weeks after treatment. Whole-brain tract-based spatial statistics was used to explore differences in white matter microstructural properties estimated from diffusion magnetic resonance imaging. Voxel-wise statistical analysis revealed a significant increase in fractional anisotropy and a decrease in radial diffusivity in forceps minor and superior longitudinal fasciculus in responders compared to non-responders. Thus, alterations in white matter integrity, specifically in forceps minor and the superior longitudinal fasciculus, are associated with paroxetine treatment response. These findings pave the way for personalized treatment strategies in major depression.

Association between Visceral and Bone Marrow Adipose Tissue and Bone Quality in Sedentary and Physically Active Ovariectomized Wistar Rats

Background: Obesity is considered protective for bone mass, but this view has been progressively challenged. Menopause is characterized by low bone mass and increased adiposity. Our aim was to determine how visceral and bone marrow adiposity change following ovariectomy (OVX), how they correlate with bone quality and if they are influenced by physical activity. Methods: Five-month-old Wistar rats were OVX or sham-operated and maintained in sedentary or physically active conditions for 9 months. Visceral and bone marrow adiposity as well as bone turnover, femur bone quality and biomechanical properties were assessed. Results: OVX resulted in higher weight, visceral and bone marrow adiposity. Visceral adiposity correlated inversely with femur Ct.Th (r = −0.63, p < 0.001), BV/TV (r = −0.67, p < 0.001), Tb.N (r = −0.69, p < 0.001) and positively with Tb.Sp (r = 0.58, p < 0.001). Bone marrow adiposity also correlated with bone resorption (r = 0.47, p < 0.01), bone formation rate (r = −0.63, p < 0.01), BV/TV (r = −0.85, p < 0.001), Ct.Th (r = −0.51, p < 0.0.01), and with higher empty osteocyte lacunae (r = 0.39, p < 0.05), higher percentage of osteocytes with oxidative stress (r = 0.64, p < 0.0.01) and lower femur maximal stress (r = −0.58, p < 0.001). Physical activity correlated inversely with both visceral (r = −0.74, p < 0.01) and bone marrow adiposity (r = −0.92, p < 0.001). Conclusions: OVX increases visceral and bone marrow adiposity which are associated with inferior bone quality and biomechanical properties. Physical activity could contribute to reduce adipose tissue and thereby improve bone quality.

Impairment of the angiogenic process may contribute to lower success rate of root canal treatments in diabetes mellitus

AIM

To investigate the association between root canal treatment outcome, diabetes mellitus, and alterations of the angiogenic process.

METHODOLOGY

A retrospective observational study was conducted in healthy (control group, CG) and diabetic (type II diabetes mellitus group, DG) patients after root canal treatment. The follow-up appointments were performed to clinically and radiographically observe symptoms, the healing of periapical lesions and the quality of root fillings. In the animal model study, diabetic Goto-Kakizaki (GK) rats and control Wistar rats were used. After 21 days of pulp exposure and the development of apical periodontitis (AP), the mandibles were removed for scintigraphic, radiographic, histopathological and molecular analyses. Chi-square tests were performed to examine the variables related to endodontic outcome and differences between animal groups were assessed using the Student's t-test.

RESULTS

The group of patients with diabetes had a significantly lower rate of success following root canal treatment than the CG (p < .001). Logistic regression suggested that diabetes is a risk factor for success of root canal treatment. In the animal study, GK rats had significantly higher fasting glycaemia at t0 and t21 (p < .001) and triglycerides levels (p < .05) and area under the curve (AUC) during the insulin tolerance test at t21 (p < .001). AP area was significantly greater in GK rats (p < .05). Histologically, diabetic rats had increased signs of periodontal ligament inflammation 21 days after the induction of apical periodontitis, with fibro-hyaline matrix filling and vessel with undefined walls. Wistar rats had significantly increased vascular endothelial growth factor (VEGF) levels and VEGF/Ang-2 ratio 21 days after AP induction (p < .08; p < .07). GK rats had intrinsically lower levels of VEGF than control rats (p < .05), which did not change after AP.

CONCLUSION

Diabetes mellitus should be considered as an important factor in the prognosis of root canal treatment and its outcomes over time. Future strategies to improve angiogenesis and tissue repair should be pursued to achieve better root canal treatment outcomes in diabetic patients.

Reorganization of brain structural networks in aging: A longitudinal study

Normal aging is characterized by structural and functional changes in the brain contributing to cognitive decline. Structural connectivity (SC) describes the anatomical backbone linking distinct functional subunits of the brain and disruption of this communication is thought to be one of the potential contributors for the age-related deterioration observed in cognition. Several studies already explored brain network's reorganization during aging, but most focused on average connectivity of the whole-brain or in specific networks, such as the resting-state networks. Here, we aimed to characterize longitudinal changes of white matter (WM) structural brain networks, through the identification of sub-networks with significantly altered connectivity along time. Then, we tested associations between longitudinal changes in network connectivity and cognition. We also assessed longitudinal changes in topological properties of the networks. For this, older adults were evaluated at two timepoints, with a mean interval time of 52.8 months (SD = 7.24). WM structural networks were derived from diffusion magnetic resonance imaging, and cognitive status from neurocognitive testing. Our results show age-related changes in brain SC, characterized by both decreases and increases in connectivity weight. Interestingly, decreases occur in intra-hemispheric connections formed mainly by association fibers, while increases occur mostly in inter-hemispheric connections and involve association, commissural, and projection fibers, supporting the last-in-first-out hypothesis. Regarding topology, two hubs were lost, alongside with a decrease in connector-hub inter-modular connectivity, reflecting reduced integration. Simultaneously, there was an increase in the number of provincial hubs, suggesting increased segregation. Overall, these results confirm that aging triggers a reorganization of the brain structural network.

Amygdala size varies with stress perception

Stress is inevitably linked to life. It has many and complex facets. Notably, perception of stressful stimuli is an important factor when mounting stress responses and measuring its impact. Indeed, moved by the increasing number of stress-triggered pathologies, several groups drew on advanced neuroimaging techniques to explore stress effects on the brain. From that, several regions and circuits have been linked to stress, and a comprehensive integration of the distinct findings applied to common individuals is being pursued, but with conflicting results. Herein, we performed a volumetric regression analysis using participants’ perceived stress as a variable of interest. Data shows that increased levels of perceived stress positively associate with the right amygdala and anterior hippocampal volumes.

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Discrepant stress effects on morphology are reported in the literature.

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Stress definition and analysis software are the main causes of conflicting findings.

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Psychological measures and multi-technique analysis are highly recommended.

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We found that perceived stress positively associates with right amygdala volumes.

Effect of Cavity Disinfectants on Adhesion to Primary Teeth-A Systematic Review

Some authors have been proposing the use of cavity disinfectants in order to reduce, or even eliminate, the effect of the microorganisms present in a dental cavity before a restoration is placed. The aim of this study was to evaluate the effect of different cavity disinfectants on bond strength and clinical success of composite and glass ionomer restorations on primary teeth. The research was conducted using Cochrane Library, PubMed/MEDLINE, SCOPUS, and Web of Science for articles published up to February 2021. The search was performed according to the PICO strategy. The evaluation of the methodological quality of each in vitro study was assessed using the CONSORT checklist for reporting in vitro studies on dental materials. Sixteen in vitro studies and one in situ study fulfilled the inclusion criteria and were analyzed. Chlorhexidine was the most studied cavity disinfectant, and its use does not compromise dentin bonding. Sodium hypochlorite is a promising alternative, but more research on its use is required to clearly state that it can safely be used as a cavity disinfectant for primary teeth. Although other disinfectants were studied, there is a low-level evidence attesting their effects on adhesion, therefore their use should be avoided.

The Influence of Irrigation during the Finishing and Polishing of Composite Resin Restorations-A Systematic Review of In Vitro Studies

The surface smoothness of composite restorations affects not only their esthetic appearance but also other properties. Thus, rough surfaces can lead to staining, plaque accumulation, gingival irritation, recurrent caries, abrasiveness, wear kinetics, and tactile perception by the patient. The aim of this study was to evaluate the influence of irrigation during the finishing and polishing of composite resin restorations. A systematic search of the PubMed, Cochrane Library, EMBASE, Web of Science, and Clinical Trials databases was conducted. Papers published up to 11 February 2021 were considered. The quality of each study was assessed using the modified Consolidated Standards of Reporting Trials checklist for reporting in vitro studies on dental materials. No clinical studies were identified. Six in vitro studies were included, reporting changes in physical and esthetic properties. After performing a methodological quality assessment of the studies, some limitations were identified, the main limitation being the heterogeneous methodology across studies. The evidence resulting from this systematic review did not favor either wet or dry finishing/polishing procedures. There is a clear need for well-designed studies focusing on the comparison of dry/wet finishing/polishing with standard protocols to evaluate the differences among different materials and methods.