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Abstract Objectives The present study reviews the current literature regarding the utilization of the extended finite element method (XFEM) in clinical and experimental endodontic studies and the suitability of XFEM in the assessment of cyclic fatigue in rotary endodontic nickel–titanium (NiTi) instruments. Material and Methods An electronic literature search was conducted using the appropriate search terms, and the titles and abstracts were screened for relevance. The search yielded 13 hits after duplicates were removed, and four studies met the inclusion criteria for review. Results No studies to date have utilized XFEM to study cyclic fatigue or crack propagation in rotary endodontic NiTi instruments. Challenges such as modelling material inputs and fatigue criteria could explain the lack of utilization of XFEM in the analysis of mechanical behavior in NiTi instruments. Conclusions The review showed that XFEM was seldom employed in endodontic literature. Recent work suggests potential promise in using XFEM for modelling NiTi structures.

Prior research has examined the relationship between ethnic outgroup-size at the neighbourhood level and Brexit support, yet there is a lack of understanding on the factors that moderate these effects. This paper critically extends prior debate by focusing on how personality traits moderate not only the extent to which the levels (2011) of ethnic outgroup-size in individuals' residential neighbourhoods but also the increase thereof (2001-2011) are associated with individuals' preferences about the 2016 Brexit referendum. Using data from Understanding Society, we find that two personality traits, agreeableness and openness, are key moderators affecting the above-mentioned relationship. High-agreeable and high-open individuals are less likely than low-agreeable and low-open individuals to support Brexit. However, while the gap between low and highly agreeable individuals shrinks as ethnic outgroup-size increases, the gap widens between those higher vs. lower in openness. Our findings highlight the multifaceted role of personality traits as a driver of heterogeneous effects on political behaviour. In sum, this paper shows that analysing the complex and intertwined nature of both contextual and individual factors is fundamental for a better understanding, not only of the Brexit referendum but, more broadly, of anti-immigrant sentiment. [ABSTRACT FROM AUTHOR]

Introduction: Diagnostic procedures for pulp vitality assessment are a crucial aspect of routine dental practice. This review aims to provide a comprehensive overview of nontraditional techniques and methodologies for assessing pulp vitality, specifically exploring promising approaches that are currently not used in dental practice. Methods: The study protocol was registered a priori (https://osf.io/3m97z/). An extensive electronic search was conducted across multiple databases, including MEDLINE via PubMed, Scopus, Web of Science, and Embase. Inclusion criteria were guided by the research question based on the PCC model as follows: "What are the potential nontraditional techniques (Concept) for assessing pulp vitality (Population) in the field of endodontics or clinical practice (Context)?" Studies were included that explored possible approaches to pulp vitality assessment, utilizing a range of techniques, whilst any studies using traditional pulp tests (cold, heat, and electric stimulation) or well‐known methods (pulse oximetry and laser Doppler flowmetry) were excluded. Reviewers independently screened articles and extracted data. A patent search was also performed. Results: Of 3062 studies, 65 were included that described nontraditional approaches for assessing pulp vitality. These included a range of optical diagnostic methods, ultrasound Doppler flowmetry (UDF), magnetic resonance imaging (MRI), terahertz imaging, tooth temperature measurements, as well as invasive methodologies, including 133xenon washout, radioisotope‐labelled tracers, hydrogen gas desaturation, intravital microscopy and fluorescent microspheres isotope clearance. The patent search included artificial intelligence and biomarkers methods. Conclusions: This review provides details for potential innovative tests that may directly describe pulp vitality. Importantly, these methods range from clinically impractical through to promising methods that may transform clinical practice. Several nontraditional techniques have the potential to enhance diagnostic accuracy and could provide valuable insights into the assessment of pulp vitality in challenging clinical scenarios. [ABSTRACT FROM AUTHOR]

Background: To evaluate the cyclic fatigue resistance of rotary endodontic nickel-titanium instruments using both experimental and finite element methods. Methodology: Four different proprietary rotary endodontic instruments (PTG, PTU, VB, and TRN) were subjected to cyclic fatigue tests through a custom-built fixture (n = 30 for each group) and tested until failure according to the manufacturer’s recommended settings, and the number of cycles to failure (NCF) was measured. Separated fragments were measured to determine the location of the fracture event. Finite element modeling replicated this experiment in silico via a two-step method, modeling the dynamic motion via an initial insertion step, then followed by rotation. Results: TRN showed the highest NCF (2027.94 ± 452.50) with the lowest values for strain (4.49% ± 0.23%) and fragment lengths (3.26 mm ± 0.47 mm), whereas PTU showed the lowest NCF (600.90 ± 80.86) and highest values for strain (6.29% ± 0.47%) and fragment lengths (5.36 mm ± 0.79 mm). All instruments showed an increase in von Mises and maximum principal stress during the insertion step but showed no changes to the maximum stress values during the rotational step. Conclusions: The finite element analysis approach used provided useful insights into the stress evolution and stress distribution of instruments during cyclic fatigue but lacked the ability with existing inputs to predict failure from cyclic fatigue.

Objectives: This study aimed to assess dentists' attitudes toward providing dental care for older adults with disabilities in Singapore and the factors influencing their willingness to provide care. Background: Dentists face a rapidly ageing patient demographic. Practitioner unwillingness to circumvent the attending challenges of care provision prevents older adults from accessing the dental care necessary for better oral and systemic health. Previous studies have reported on dentists' attitudes toward caring for older adults with disabilities; however, these are mostly limited to dependent older adults and exclude frail, community‐dwelling older persons. Methods: A cross‐sectional study was conducted in 2020 using a self‐administered questionnaire. Quantitative data analysis was presented in the form of descriptive statistics, followed by bivariate analyses. Results: There were 193 respondents, a response rate of under 9%. Dentists were less willing, confident and involved in the care of older adults with disabilities as the individual's severity of impairments increased. Less than half of respondents were willing to treat individuals with severe disabilities in cooperation (23.3%), swallowing (30.6%), mobility (33.7%) and communication (45.1%). Dentists with training in geriatric dentistry were more willing to provide care. However, younger dentists, general dental practitioners, private practitioners and public sector dentists had specific restraining and driving forces, which further modulated their willingness to provide care. Conclusions: The current areas of training needs among Singapore dentists are in severe impairments of swallowing, communication, cooperation and mobility. Further geriatric dentistry training may effectively increase dentists' willingness to provide care; however, additional specific targeted interventions are also needed. [ABSTRACT FROM AUTHOR]

Purpose. This in vitro study compared root canal preparation in curved mesiobuccal canals of molar teeth using either the One Shape™ or the Neoniti (Neolix) rotary NiTi single-file systems, assessing canal transportation, instrument separation and time required for preparation. Methods. Extracted maxillary and mandibular human molar teeth with mesiobuccal canals having apical angles of curvature between 25 and 35o were selected and embedded in acrylic resin blocks, and an initial CBCT was taken. The teeth were divided into two equal groups (n = 20), and the canals were cleaned and shaped using either Neoniti™ or One Shape™ engine-driven NiTi rotary files. Each individual instrument was used to prepare 5 canals. The time required for the preparation of each canal was recorded. Postpreparation CBCT scans were taken and used to determine the extent of canal transportation at levels of 2, 4, 6, and 8 mm from the apex. The Kolmogorov–Smirnov test for normality was applied, and then, datasets were compared using independent t-tests, with a threshold of P

The COVID-19 pandemic has wrought acute harm to global mental health, especially among vulnerable populations. We explore what factors in people's lives buffered the impact of the pandemic on depression; in particular, the role of social resources, economic resources, religiosity, and quality of their local environment. Drawing on three waves of longitudinal cohort data (two pre-pandemic waves and one pandemic-period wave) from primary caregivers of school-aged children in Ireland, we demonstrate that symptoms of depression increased sharply during the pandemic. However, depression symptomology increased less steeply among caregivers who, pre-pandemic, had greater economic resources and lived in higher quality environments, but especially among those with greater social resources and those who exhibited greater religiosity. Path analysis suggests that different sources of buffering might mitigate harm via different pathways. While most buffering factors appear to cushion mental well-being by reducing stresses from increased care work, improving familial relations, and helping caregivers manage the closure of/return to schools, other drivers appear to cushion mental well-being by reducing health anxieties around COVID-19, increasing opportunities for outdoor exercise, and protecting household incomes. This study highlights how crisis-preparedness should invest in social infrastructure alongside medical infrastructure to protect societies from future pandemics. [ABSTRACT FROM AUTHOR]

Introduction: Oral health therapists (OHTs) are a valuable resource for increasing access to dental care for the frail elderly in nursing homes (NHs). However, OHTs face several barriers and their skill‐set continues to be under‐utilized. Aims: To evaluate the perceptions of OHTs regarding the barriers towards oral care provision for the elderly residents in NHs. Methodology: Semi‐structured interviews were conducted with 11 OHTs to discuss the factors that may hinder them from providing oral health services in NHs. An inductive thematic analysis directed by the grounded theory approach was performed. Results: Four major themes emerged: (i) lack of opportunity, (ii) lack of adequate education and training, (iii) limited work scope and registration status, and (iv) lack of adequate financial remuneration and adequate equipment. OHTs also raised the lack of awareness among OHTs and the various stakeholders, of how the skill‐set of OHTs may be relevant for oral care provision in NHs. Conclusion: Findings revealed underlying educational and regulatory barriers which need to be addressed in tandem. Addressing these barriers can be impactful in informing future strategies for the greater utilization of the skill‐set of OHTs in Singapore. [ABSTRACT FROM AUTHOR]

Objectives: To assess the effects on curing conditions (dry versus submerged curing) and particle size on the compressive strength (CS) and flexural strength (FS) of set MTA cement. Materials and methods: Two different Portland cements were created, P1 and P2, with P1

Objective The current standard used to measure setting time for Mineral Trioxide Aggregate (MTA) involves indentation testing with arbitrary weights. This study compared indentation testing against rheological measurements and assessed the influences of particle size and the inclusion of bismuth oxide on the setting time of experimental MTA and Portland cement (PC). Material and methods Two PCs (P1 and P2) of different particle sizes were produced using the same clinker. From these two PCs, two experimental MTAs (M1 and M2) were created with the addition of bismuth oxide. Particle size distributions were assessed using laser diffraction analysis. Indentation setting time tests were performed in accordance to the Gillmore needle test. Elastic modulus was assessed using a strain-controlled rheometer at 1 rad s−1 and an applied strain of 0.01%. Results P1, P2, M1 and M2 cements had median particle sizes of 6.1, 12.5, 6.5 and 13.0 μm, respectively. Using indentation testing, final setting times were ranked P1

Objective Mineral trioxide aggregate (MTA) cements contain two types of particles, namely Portland cement (PC) (nominally 80% w/w) and bismuth oxide (BO) (20%). This study aims to determine the particle size distribution (PSD) of PC and BO found in MTA. Materials and methods The PSDs of ProRoot MTA (MTA-P) and MTA Angelus (MTA-A) powder were determined using laser diffraction, and compared to samples of PC (at three different particle sizes) and BO. The non-linear least squares method was used to deconvolute the PSDs into the constituents. MTA-P and MTA-A powders were also assessed with scanning electron microscopy. Results BO showed a near Gaussian distribution for particle size, with a mode distribution peak at 10.48 μm. PC samples milled to differing degrees of fineness had mode distribution peaks from 19.31 down to 4.88 μm. MTA-P had a complex PSD composed of both fine and large PC particles, with BO at an intermediate size, whereas MTA-A had only small BO particles and large PC particles. Conclusions The PSD of MTA cement products is bimodal or more complex, which has implications for understanding how particle size influences the overall properties of the material. Smaller particles may be reactive PC or unreactive radiopaque agent. Manufacturers should disclose particle size information for PC and radiopaque agents to prevent simplistic conclusions being drawn from statements of average particle size for MTA materials.