Effects of Reciproc, ProTaper Next and WaveOne Gold on Root Canal Walls: A Stereomicroscope Analysis

Introduction: The aim of this study was to analyse the potential occurrence of dentinal defects after root canal preparation using three engine-driven instruments. Methods and Materials: Eighty permanent mandibular incisors were selected. Twenty teeth did not undergo preparation, and the remaining teeth were divided into three groups (n=20): Reciproc (REC), ProTaper Next (PTN) and WaveOne Gold (WOG). The samples were dyed with methylene blue, sectioned perpendicularly to the long axis in 3-, 6- and 9-mm slices and were finally observed under a stereomicroscope (under 25×). The absence/presence of dentinal defects was documented by two blind observers. The data were analysed using Pearson’s chi-squared test with a confidence level of 95% (P=0.05). The time to prepare the samples was recorded, and the groups were compared using F-test (ANOVA). Results: The control group did not present any defects, and the differences between the control and experimental groups were statistically significant (P<0.05). WOG, PTN and REC caused microcracks on 60%, 33.33% and 18.33% of the samples, respectively. No significant differences between the groups in the 3-mm sections (P=0.126) were observed. There were significant differences in the 6-mm (P=0.042) and 9-mm sections (P<0.001). When WOG and PTN were used to perform root canal preparation, a significant difference was found in the average time (P=0.047). Conclusion: All the used instruments caused dentinal defects in the root dentin. All the instruments were used to perform the preparation with a similar average time.Keywords: Dentinal Defects; Microcracks; Nickel-Titanium Instruments; Root Canal Preparatio

Bacterial Reduction after Gutta-Percha Removal with Single vs. Multiple Instrument Systems

Introduction: The aim of this study was to evaluate the effectiveness of a reciprocating single-instrument system (Reciproc-REC) compared with combined continuously rotating multiple-instrument systems [D-Race (DR) and BioRace (BR)] in reducing Enterococcus faecalis (E.f.) after gutta-percha removal. Methods and Materials: Forty-six extracted human maxillary incisors were prepared and contaminated with E.f. strain (ATCC 29212) for 30 days. The samples were obturated and randomly divided into two experimental groups for gutta-percha removal (n=23): a REC group (R50) and a DR/BR group (DR1, DR2 and BR6). A standardized irrigation with 0.9% saline solution was performed. Root canal samples were taken with paper points before (S1) and after (S2) the removal of gutta-percha to establish bacterial quantification by culture. The time required for gutta-percha removal was also recorded. Positive and negative control groups (n=6) were used to test bacterial viability and control asepsis, respectively. Data were analysed using t-Student and one-way ANOVA tests (5% margin of error). Results: The mean percentage of bacterial reduction was significantly higher in DR/BR group (84.2%) than in REC group (72.3%) (P<0.05). The mean time for obturation removal was 74.00 sec in REC group and 107.53 sec in DR/BR group (P<0.05). Conclusion: The combined continuously rotating multiple-instrument system was more effective in reducing bacteria after the removal of gutta-percha than the single-instrument system. None of the tested systems was able to completely eliminate root canal infection after gutta-percha removal. Thus, additional techniques should be considered.Keywords: Endodontics; Enterococcus faecalis; Instrumentation; Retreatment; Root Canal Instrumentatio

Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion

This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n=20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer’s instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α=5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p<0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p<0.001). Cross section and motion influenced the results, despite tip standardization

Free recall of bound information held in short-term memory is unimpaired by age and education

Objectives: It has been challenging to identify cognitive markers to differentiate healthy brain aging from neurodegeneration due to Alzheimer’s disease (AD) that are not affected by age and education. The Short-Term Memory Binding (STMB) showed not to be affected by age or education when using the change detection paradigm. However, no previous study has tested the effect of age and education using the free recall paradigm of the STMB. Therefore, the objective of this study was to investigate age and education effects on the free recall version of the STMB test under different memory loads. Methods: 126 healthy volunteers completed the free recall STMB test. The sample was divided into five age bands and into five education bands for comparisons. The STMB test assessed free recall of two (or three) common objects and two (or three) primary colors presented as individual features (unbound) or integrated into unified objects (bound). Results: The binding condition and the larger set size generated lower free recall scores. Performance was lower in older and less educated participants. Critically, neither age nor education modified these effects when compared across experimental conditions (unbound versus bound features). Conclusions: Binding in short-term memory carries a cost in performance. Age and education do not affect such a binding cost within a memory recall paradigm. These findings suggest that this paradigm is a suitable cognitive marker to differentiate healthy brain aging from age-related disease such as AD

Validity and Reliability of the Frontotemporal Dementia Rating Scale (FTD-FRS) for the Progression and Staging of Dementia in Brazilian Patients

Introduction: Few studies on instruments for staging frontotemporal dementia (FTD) have been conducted.  Objective: The objective of this study was to analyze the factor structure, internal consistency, reliability, and convergent validity of the Brazilian version of the Frontotemporal Dementia Rating Scale (FTD-FRS).  Methods: A total of 97 individuals aged 40 years and above with >2 years’ education took part in the study, 31 patients diagnosed with behavioral variant FTD (bvFTD), 8 patients with primary progressive aphasia, 28 with Alzheimer disease, 8 with mild cognitive impairment, and a control group of 22 healthy subjects. The FTD-FRS was completed by family members or caregivers, and Neurologists completed the 8-item Clinical Dementia Rating for Frontotemporal Lobar Degeneration (CDR-FTLD) scale (6 original domains plus Language and Behavior). The Alzheimer disease and FTD patients had equivalent disease severity level.  Results: The internal consistency of the FTD-FRS, estimated by Cronbach α, was 0.975 whereas test-retest reliability was 0.977. Scree plot and exploratory factor (Varimax rotation) analyses revealed the existence of 4 factors, with eigenvalues >1, which together explained 77.13% of the total variance with values of 1.28 to 17.52. The domains of the Brazilian version of the FTD-FRS scale correlated with the domains of the CDR-FTLD.  Conclusions: The present study is the first to document the factorial structure of the FTD-FRS and its convergent validity with the CDR-FTLD. These tools are key to determine dementia severity in FTD. The Brazilian FTD-FRS demonstrated adequate psychometric properties for use in Brazil. This instrument may contribute to disease staging in FTD and may help to document intervention-related changes

Profiles of cognitive impairment in the continuum from normal cognition to Alzheimer's Clinical Syndrome:Contributions of the Short-term Memory Binding tests

Background: Short-term memory binding (STMB) tests assess conjunctive binding, in which participants should remember the integration of features, such as shapes (or objects) and colors, forming a unique representation in memory. In this study, we investigated two STMB paradigms: change detection (CD) and free recall (FR). Objective: To investigate the cognitive profile in the CD and FR tasks of three diagnostic groups: cognitively unimpaired (CU), mild cognitive impairment (MCI), and Alzheimer's clinical syndrome (ACS). In addition, we aimed to calculate and compare the accuracy of the CD and FR tasks to identify MCI and ACS. Methods: Participants were 24 CU, 24 MCI, and 37 ACS. The cognitive scores of the clinical groups were compared using analysis of variance (ANOVA) and receiver-operating characteristic (ROC) analyses were carried out to verify the accuracy of the STMB tasks. Results: In the CD task, CU was different from MCI and ACS (CU > MCI = ACS), while in the FR task all groups were different (CU > MCI > ACS). The ROC analyses showed an area under the curve (AUC) of 0.855 comparing CU with MCI for the CD task and 0.975 for the FR. The AUC comparing CU and ACS was 0.924 for the CD and 0.973 for the FR task. The FR task showed better accuracy to identify MCI patients, and the same accuracy to detect ACS. Conclusion: The present findings indicate that impairments in CD and FR of bound representations are features of the cognitive profiles of MCI and ACS patients

Disease progression in frontotemporal dementia and Alzheimer disease: the contribution of staging scales

Introduction: There is a shortage of validated instruments to estimate disease progression in frontotemporal dementia (FTD). Objectives: To evaluate the ability of the FTD Rating Scale (FTD-FRS) to detect functional and behavioral changes in patients diagnosed with the behavioral variant of FTD (bvFTD), primary progressive aphasia (PPA) and Alzheimer disease (AD) after 12 months of the initial evaluation, compared to the Clinical Dementia Rating scale - frontotemporal lobar degeneration (CDR-FTLD) and the original Clinical Dementia Rating scale (CDR). Methods: The sample consisted of 70 individuals, aged 40+ years, with at least two years of schooling, 31 with the diagnosis of bvFTD, 12 with PPA (8 with semantic variant and 4 with non-fluent variant) and 27 with AD. The FTD-FRS, the CDR and the two additional CDR-FTLD items were completed by a clinician, based on the information provided by the caregiver with frequent contact with the patient. The Addenbrooke’s Cognitive Examination-Revised (ACE-R) was completed by patients. After 12 months, the same protocol was applied. Results: The FTD-FRS, CDR-FTLD and CDR detected significant decline after 12 months in the three clinical groups (exception: FTD-FRS for PPA). The CDR was less sensitive to severe disease stages. Conclusions: The FTD-FRS and the CDR-FTLD are especially useful tools for dementia staging in AD and in the FTD spectrum

The impact of culture on neuropsychological performance: A global social cognition study across 12 countries

AbstractBackgroundDecades of researches aiming to unveil truths about human neuropsychology may have instead unveil facts appropriate to only a fraction of the world's population: those living in western educated rich democratic nations (Muthukrishna et al., 2020 Psych Sci). So far, most studies were conducted as if education and cultural assumptions on which neuropsychology is based were universals and applied everywhere in the world. The importance given to sociological or cultural factors is thus still relatively ignored. With the growth of international clinical studies on dementia, we believe that documenting the potential inter‐cultural differences at stake in a common neuropsychological assessment is an essential topic. This study thus aimed to explore these potential variations in two classical tasks used in neuropsychology that are composing the mini‐SEA (Bertoux et al., 2012 JNNP), i.e. a reduced version of the well‐known Ekman faces (FER), where one has to recognize facial emotions, and a modified version of the Faux Pas test (mFP), where one has to detect and explain social faux.MethodThe data of 573 control participants were collected through the Social Cognition & FTLD Network, an international consortium investigating social cognitive changes in dementia covering 3 continents (18 research centres in 12 countries). Impact of demographic factors and the effect of countries on performance (mini‐SEA, FER, mFP) were explored through linear mixed‐effects models.ResultAge, education and gender were found to significantly impact the performance of the mini‐SEA subtests. Significant and important variations across the countries were also retrieved, with England having the highest performance for all scores. When controlling for demographical factors, differences within countries explained between 14% (mFP) and 24% (FER) of the variance at the mini‐SEA. These variations were not explained by any economical or sociological metrics.ConclusionImportant variations of performance were observed across the 12 countries of the consortium, showing how cultural differences may critically impact neuropsychological performance in international studies

Does Culture Shape Our Understanding of Others’ Thoughts and Emotions? An Investigation Across 12 Countries

Q2Q2Measures of social cognition have now become central in neuropsychology, being essential for early and differential diagnoses, follow-up, and rehabilitation in a wide range of conditions. With the scientific world becoming increasingly interconnected, international neuropsychological and medical collaborations are burgeoning to tackle the global challenges that are mental health conditions. These initiatives commonly merge data across a diversity of populations and countries, while ignoring their specificity. Objective: In this context, we aimed to estimate the influence of participants’ nationality on social cognition evaluation. This issue is of particular importance as most cognitive tasks are developed in highly specific contexts, not representative of that encountered by the world’s population. Method: Through a large international study across 18 sites, neuropsychologists assessed core aspects of social cognition in 587 participants from 12 countries using traditional and widely used tasks. Results: Age, gender, and education were found to impact measures of mentalizing and emotion recognition. After controlling for these factors, differences between countries accounted for more than 20% of the variance on both measures. Importantly, it was possible to isolate participants’ nationality from potential translation issues, which classically constitute a major limitation. Conclusions: Overall, these findings highlight the need for important methodological shifts to better represent social cognition in both fundamental research and clinical practice, especially within emerging international networks and consortia.https://orcid.org/0000-0001-9422-3579https://orcid.org/0000-0001-6529-7077Revista Internacional - IndexadaA2N

Estratégias de aquisição da casa própria: a trajetória de algumas famílias negras paulistanas nas décadas de 1920 a 1940

In Brazil, there is a cultural belief that property acquisition is the wisest attitude to ensure a safe and stable economy. For generations, the "dream of property ownership" has been cultivated as a horizon to be achieved. Confirming this tendency, since the 1920s, "casa propria" (home ownership) became a notion mobilized in the black press periodicals, circulating as a desirable aspiration and an orientation to the journals public. Between 1924 and 1937, two of the main newspapers of São Paulo black press, O Clarim da Alvorada and A Voz da Raça, carried out a campaign in favor of property ownership, spreading among paulista black families the importance of property acquisition. These campaigns are an important sign for the relevance of buying a property for black families at that time. In this paper, we seek to analyze it as an intergenerational social security strategy, through the presentation of three cases of black families that accomplished this goal between 1920s and 1940s. The black families testimonies reported here indicate precocity, specificities and strategies that represent new challenges for the formulation of property ownership problem, from a racial point of view.No Brasil, há uma crença cultural de que a atitude mais sábia para garantir uma economia doméstica segura e estável é a aquisição da casa própria. Por gerações, o “sonho da casa própria” tem sido cultivado como um horizonte a se atingir. Confirmando essa tendência, desde a década de 1920, a “casa própria” torna-se uma noção mobilizada nos periódicos da imprensa negra, circulando em diversos artigos como uma aspiração desejável e uma orientação ao público dos jornais. Entre 1924 e 1937, dois dos principais jornais da imprensa negra paulista, O Clarim da Alvorada e A Voz da Raça, realizaram uma campanha em favor da casa própria, difundindo entre as famílias negras paulistanas a ideia da importância da aquisição imobiliária. Essas campanhas constituem um indício importante da relevância da aquisição residencial para as famílias negras do período. Neste trabalho, procuramos analisar essa importância como estratégia de seguridade social intergeracional, por meio da apresentação de três casos de famílias negras que realizaram esse objetivo entre as décadas de 1920 e 1940. Os depoimentos das famílias negras aqui reportados indicamprecocidade, especificidades e estratégias que representam novos desafios para a reflexão sobre a formulação do problema da casa própria, a partir do ponto de vista racial