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1.
Elife ; 122023 07 05.
Article in English | MEDLINE | ID: mdl-37403921

ABSTRACT

Brazil would benefit from a long-term strategy for science and innovation that improves the standing of both science and scientists in the country.


Subject(s)
Research , Science , Brazil , Research/trends , Inventions
2.
Elife ; 122023 05 16.
Article in English | MEDLINE | ID: mdl-37191660

ABSTRACT

It is quite well documented that the COVID-19 pandemic disrupted cancer screening services in all countries, irrespective of their resources and healthcare settings. While quantitative estimates on reduction in volume of screening tests or diagnostic evaluation are readily available from the high-income countries, very little data are available from the low- and middle-income countries (LMICs). From the CanScreen5 global cancer screening data repository we identified six LMICs through purposive sampling based on the availability of cancer screening data at least for the years 2019 and 2020. These countries represented those in high human development index (HDI) categories (Argentina, Colombia, Sri Lanka, and Thailand) and medium HDI categories (Bangladesh and Morocco). No data were available from low HDI countries to perform similar analysis. The reduction in the volume of tests in 2020 compared to the previous year ranged from 14.1% in Bangladesh to 72.9% in Argentina (regional programme) for cervical screening, from 14.2% in Bangladesh to 49.4% in Morocco for breast cancer screening and 30.7% in Thailand for colorectal cancer screening. Number of colposcopies was reduced in 2020 compared to previous year by 88.9% in Argentina, 38.2% in Colombia, 27.4% in Bangladesh, and 52.2% in Morocco. The reduction in detection rates of CIN 2 or worse lesions ranged from 20.7% in Morocco to 45.4% in Argentina. Reduction of breast cancer detection by 19.1% was reported from Morocco. No association of the impact of pandemic could be seen with HDI categories. Quantifying the impact of service disruptions in screening and diagnostic tests will allow the programmes to strategize how to ramp up services to clear the backlogs in screening and more crucially in further evaluation of screen positives. The data can be used to estimate the impact on stage distribution and avoidable mortality from these common cancers.


Subject(s)
COVID-19 , Uterine Cervical Neoplasms , Female , Humans , Thailand , Early Detection of Cancer , Uterine Cervical Neoplasms/diagnosis , Uterine Cervical Neoplasms/epidemiology , Pandemics , Bangladesh , Sri Lanka , Argentina , Colombia/epidemiology , Morocco/epidemiology , COVID-19/diagnosis , COVID-19/epidemiology , Developing Countries
3.
Elife ; 112022 02 17.
Article in English | MEDLINE | ID: mdl-35175198

ABSTRACT

A method called functional connectivity mapping helps model some of the complex interactions between multiple ecosystem services.


Subject(s)
Conservation of Natural Resources , Ecosystem
4.
Elife ; 102021 08 05.
Article in English | MEDLINE | ID: mdl-34350825

ABSTRACT

Understanding the origin and maintenance of biodiversity is a fundamental problem. Many theoretical approaches have been investigating ecological interactions, such as competition, as potential drivers of diversification. Classical consumer-resource models predict that the number of coexisting species should not exceed the number of distinct resources, a phenomenon known as the competitive exclusion principle. It has recently been argued that including physiological tradeoffs in consumer-resource models can lead to violations of this principle and to ecological coexistence of very high numbers of species. Here, we show that these results crucially depend on the functional form of the tradeoff. We investigate the evolutionary dynamics of resource use constrained by tradeoffs and show that if the tradeoffs are non-linear, the system either does not diversify or diversifies into a number of coexisting species that do not exceed the number of resources. In particular, very high diversity can only be observed for linear tradeoffs.


Subject(s)
Biodiversity , Biological Evolution , Metabolism , Biochemical Phenomena , Ecosystem , Models, Biological , Population Dynamics , Species Specificity
5.
Elife ; 102021 06 01.
Article in English | MEDLINE | ID: mdl-34058123

ABSTRACT

Towards the goal of malaria elimination on Hispaniola, the National Malaria Control Program of Haiti and its international partner organisations are conducting a campaign of interventions targeted to high-risk communities prioritised through evidence-based planning. Here we present a key piece of this planning: an up-to-date, fine-scale endemicity map and seasonality profile for Haiti informed by monthly case counts from 771 health facilities reporting from across the country throughout the 6-year period from January 2014 to December 2019. To this end, a novel hierarchical Bayesian modelling framework was developed in which a latent, pixel-level incidence surface with spatio-temporal innovations is linked to the observed case data via a flexible catchment sub-model designed to account for the absence of data on case household locations. These maps have focussed the delivery of indoor residual spraying and focal mass drug administration in the Grand'Anse Department in South-Western Haiti.


Subject(s)
Endemic Diseases , Malaria/epidemiology , Seasons , Antimalarials/therapeutic use , Bayes Theorem , Catchment Area, Health , Endemic Diseases/prevention & control , Haiti/epidemiology , Humans , Incidence , Malaria/diagnosis , Malaria/prevention & control , Models, Statistical , Mosquito Control , Spatio-Temporal Analysis , Time Factors
6.
Elife ; 92020 05 22.
Article in English | MEDLINE | ID: mdl-32441650

ABSTRACT

The pressure for every research article to tell a clear story often leads researchers in the life sciences to exclude experiments that 'did not work' when they write up their results. However, this practice can lead to reporting bias if the decisions about which experiments to exclude are taken after data have been collected and analyzed. Here we discuss how to balance clarity and thoroughness when reporting the results of research, and suggest that predefining the criteria for excluding experiments might help researchers to achieve this balance.


Subject(s)
Publications/standards , Research/standards , Science/standards , Bias , Humans
7.
Elife ; 82019 07 31.
Article in English | MEDLINE | ID: mdl-31364991

ABSTRACT

We analyzed how often and in what ways the Journal Impact Factor (JIF) is currently used in review, promotion, and tenure (RPT) documents of a representative sample of universities from the United States and Canada. 40% of research-intensive institutions and 18% of master's institutions mentioned the JIF, or closely related terms. Of the institutions that mentioned the JIF, 87% supported its use in at least one of their RPT documents, 13% expressed caution about its use, and none heavily criticized it or prohibited its use. Furthermore, 63% of institutions that mentioned the JIF associated the metric with quality, 40% with impact, importance, or significance, and 20% with prestige, reputation, or status. We conclude that use of the JIF is encouraged in RPT evaluations, especially at research-intensive universities, and that there is work to be done to avoid the potential misuse of metrics like the JIF.


Subject(s)
Career Mobility , Journal Impact Factor , Research Personnel , Work Performance , Canada , Humans , United States , Universities
8.
Elife ; 82019 05 23.
Article in English | MEDLINE | ID: mdl-31120419

ABSTRACT

One of the challenges faced by global disease surveillance efforts is the lack of comparability across systems. Reporting commonly focuses on overall incidence, despite differences in surveillance quality between and within countries. For most immunizing infections, the age distribution of incident cases provides a more robust picture of trends in transmission. We present a framework to estimate transmission intensity for dengue virus from age-specific incidence data, and apply it to 359 administrative units in Thailand, Colombia, Brazil and Mexico. Our estimates correlate well with those derived from seroprevalence data (the gold standard), capture the expected spatial heterogeneity in risk, and correlate with known environmental drivers of transmission. We show how this approach could be used to guide the implementation of control strategies such as vaccination. Since age-specific counts are routinely collected by masany surveillance systems, they represent a unique opportunity to further our understanding of disease burden and risk for many diseases.


Subject(s)
Dengue/epidemiology , Epidemiological Monitoring , Age Distribution , Brazil/epidemiology , Colombia/epidemiology , Dengue/transmission , Humans , Incidence , Mexico/epidemiology , Prevalence , Thailand/epidemiology
9.
Elife ; 62017 12 05.
Article in English | MEDLINE | ID: mdl-29206105

ABSTRACT

TRPV1 channels support the detection of noxious and nociceptive input. Currently available functional and structural data suggest that TRPV1 channels have two gates within their permeation pathway: one formed by a 'bundle-crossing' at the intracellular entrance and a second constriction at the selectivity filter. To describe conformational changes associated with channel gating, the fluorescent non-canonical amino acid coumarin-tyrosine was genetically encoded at Y671, a residue proximal to the selectivity filter. Total internal reflection fluorescence microscopy was performed to image the conformational dynamics of the channels in live cells. Photon counts and optical fluctuations from coumarin encoded within TRPV1 tetramers correlates with channel activation by capsaicin, providing an optical marker of conformational dynamics at the selectivity filter. In agreement with the fluorescence data, molecular dynamics simulations display alternating solvent exposure of Y671 in the closed and open states. Overall, the data point to a dynamic selectivity filter that may serve as a gate for permeation.


Cells use proteins on their surface as sensors to help them to assess and explore their environments and adapt to external conditions. The transient receptor potential (TRP) ion channels form one such family of proteins. Sodium, potassium and calcium ions can move through TRP channels to enter and exit cells, and by doing so trigger changes in the cell that help it respond to an external stimulus. The channels have physical "gates" that can open and close to control the flow of the ions. When the TRP channel detects a stimulus ­ which could take the form of specific chemicals, or a change in temperature, pressure or voltage ­ it changes shape, causing the gate to open. Researchers have a number of unanswered questions about how TRP channels work. Where in the channels are gates located? How do the channels control the flow of ions, and how do they communicate with each other? And which regions of the protein sense environmental cues? As a result, new technologies are being developed to make it easier to study the types of rearrangements that TRP channels experience when they activate. Steinberg, Kasimova et al. have used total internal reflection microscopy ­ a method that images fluorescent molecules ­ to measure the conformational change of a single TRP channel in a living cell. This channel, called TRPV1, senses external heat and plays an important role in pain perception. Its gate can also be opened by the pungent compound of chili pepper, capsaicin. The results of the experiments suggest that a selectivity filter region in TRPV1 channels changes its shape when the channel opens in response to capsaicin. Then, this selectivity filter appears to do double duty ­ it controls which types of ions pass through the channels as well as controlling their flow rate. Because of its role in pain perception, having a better understanding of how TRPV1 works will be valuable for researchers who are trying to develop new pain relief treatments. The so-called 'seeing is believing' method used by Steinberg, Kasimova et al. could also be used to study other membrane proteins, both to guide drug development and to improve our understanding of how cells interact with their environment.


Subject(s)
Coumarins/analysis , TRPV Cation Channels/chemistry , TRPV Cation Channels/metabolism , Tyrosine/analysis , Capsaicin/metabolism , HEK293 Cells , Humans , Intravital Microscopy , Microscopy, Fluorescence , Models, Molecular , Molecular Dynamics Simulation , Protein Conformation , Staining and Labeling , TRPV Cation Channels/genetics
10.
Elife ; 52016 07 07.
Article in English | MEDLINE | ID: mdl-27387362

ABSTRACT

Open access, open data, open source and other open scholarship practices are growing in popularity and necessity. However, widespread adoption of these practices has not yet been achieved. One reason is that researchers are uncertain about how sharing their work will affect their careers. We review literature demonstrating that open research is associated with increases in citations, media attention, potential collaborators, job opportunities and funding opportunities. These findings are evidence that open research practices bring significant benefits to researchers relative to more traditional closed practices.


Subject(s)
Access to Information , Open Access Publishing , Research Personnel/psychology , Research/trends
11.
J Contemp Dent Pract ; 17(1): 27-31, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-27084859

ABSTRACT

OBJECTIVE: The aim of this study is to evaluate the correlation between hepatitis C virus (HCV) infection and oral lichen planus (OLP), and further examine the relationship between age, sex, systemic diseases and drugs with the presence of HCV infection or OLP. MATERIAL AND METHODS: A longitudinal clinical study was carried out from March 2010 to December 2013 with 51 individuals, of whom 33 had been presented with HCV (HCV-positive group) and 18 had OLP (OLP-positive group), in Passo Fundo, RS, Brazil. Hepatitis C virus-positive individuals who presented lesions compatible with OLP were subjected to an intraoral biopsy for histopathological diagnosis, while OLP-positive individuals underwent anti-HCV serological test for diagnosis of HCV infection. Data on age, sex, systemic diseases and drugs used were recorded for later analysis. The data were analyzed using descriptive statistics of frequency and by Pearson's Chi-square test, with a 5% significance level (p < 0.05). RESULTS: Out of the 33 HCV-positive individuals, only one was clinically and pathologically positive for OLP, demonstrating a significant relationship between the presence of HCV infection and the manifestation of OLP (Chi-square test -46.852, p = 7.65 × 10(-12)). None of the individuals in OLP-positive group had HCV infection. The most common systemic diseases were hypertension and diabetes, and the most commonly used drugs were antihypertensives. However, there was no significant relationship between these factors and the presence of OLP or HCV infection (p > 0.05). CONCLUSION: There was a significant relationship between HCV infection and manifestation of OLP. Age, sex, systemic diseases and drugs were not identified as risk factors for the development of these diseases. CLINICAL SIGNIFICANCE: The OLP could serve as an indicative of HCV infection in asymptomatic patients, thus enabling early diagnosis and treatment of hepatitis and hence, a better prognosis.


Subject(s)
Hepatitis C/epidemiology , Lichen Planus, Oral/epidemiology , Adult , Aged , Brazil/epidemiology , Case-Control Studies , Female , Humans , Longitudinal Studies , Male , Middle Aged , Risk Factors
12.
J Contemp Dent Pract ; 17(1): 63-9, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-27084865

ABSTRACT

AIM: The purpose of this study was to evaluate the dentoskeletal and soft tissue effects resulting from treatment with Klammt's elastic open activator (EOA) functional orthopedic appliance in patients with Class II malocclusion characterized by mandibular deficiency. MATERIALS AND METHODS: Teleradiographs were evaluated in the lateral aspect of the initial (T1) and final (T2) orthopedic phases for 16 patients with Class II, Division 1 malocclusion. The age range was from 9 to 11.2 years, with a mean age of 9.9 years. The cephalometric points were demarcated, and cephalometric measurements were obtained by the same investigator to avoid interobserver variability. RESULTS: The EOA promoted increased lower anterior facial height (LAFH), increased effective mandibular length, clockwise rotation of the mandible, retrusion and verticalization of the upper incisors, proclination and protrusion of the lower incisors, extrusion of the upper molars, mesial movement of the lower molars and anterior projection of the lower lip. CONCLUSION: Skeletal changes characterized by an increase in mandibular length and dentoalveolar changes with an emphasis on the verticalization and retrusion of the upper incisors, proclination of the lower incisors and mesial positioning of the lower molars were key to improving the occlusal relationship and esthetic facial factors. CLINICAL SIGNIFICANCE: The EOA is well indicated in patients with Class II malocclusion due to mandibular deficiency with increased overbite, proclined upper incisors and verticalized lower incisors.


Subject(s)
Activator Appliances , Malocclusion, Angle Class II/therapy , Cephalometry , Child , Female , Humans , Male , Malocclusion , Mandible
13.
Elife ; 5: e16207, 2016 04 19.
Article in English | MEDLINE | ID: mdl-27090085

ABSTRACT

The discovery of perfectly preserved 113-119 million year old fossilised hearts in a Brazilian fish Rhacolepis has significant implications for palaeontology and comparative anatomy.


Subject(s)
Biological Evolution , Fossils , Animals , Brazil , Fishes/anatomy & histology , Heart , Humans , Phylogeny
14.
Elife ; 5: e14698, 2016 Apr 19.
Article in English | MEDLINE | ID: mdl-27090087

ABSTRACT

Elucidating cardiac evolution has been frustrated by lack of fossils. One celebrated enigma in cardiac evolution involves the transition from a cardiac outflow tract dominated by a multi-valved conus arteriosus in basal actinopterygians, to an outflow tract commanded by the non-valved, elastic, bulbus arteriosus in higher actinopterygians. We demonstrate that cardiac preservation is possible in the extinct fish Rhacolepis buccalis from the Brazilian Cretaceous. Using X-ray synchrotron microtomography, we show that Rhacolepis fossils display hearts with a conus arteriosus containing at least five valve rows. This represents a transitional morphology between the primitive, multivalvar, conal condition and the derived, monovalvar, bulbar state of the outflow tract in modern actinopterygians. Our data rescue a long-lost cardiac phenotype (119-113 Ma) and suggest that outflow tract simplification in actinopterygians is compatible with a gradual, rather than a drastic saltation event. Overall, our results demonstrate the feasibility of studying cardiac evolution in fossils.


Subject(s)
Fishes/anatomy & histology , Fossils , Heart/anatomy & histology , Animals , Biological Evolution , X-Ray Microtomography
15.
Elife ; 52016 Feb 24.
Article in English | MEDLINE | ID: mdl-26910315

ABSTRACT

Recently, a prototype dengue early warning system was developed to produce probabilistic forecasts of dengue risk three months ahead of the 2014 World Cup in Brazil. Here, we evaluate the categorical dengue forecasts across all microregions in Brazil, using dengue cases reported in June 2014 to validate the model. We also compare the forecast model framework to a null model, based on seasonal averages of previously observed dengue incidence. When considering the ability of the two models to predict high dengue risk across Brazil, the forecast model produced more hits and fewer missed events than the null model, with a hit rate of 57% for the forecast model compared to 33% for the null model. This early warning model framework may be useful to public health services, not only ahead of mass gatherings, but also before the peak dengue season each year, to control potentially explosive dengue epidemics.


Subject(s)
Dengue/epidemiology , Epidemiologic Methods , Brazil/epidemiology , Communicable Disease Control/methods , Dengue/prevention & control , Disease Transmission, Infectious/prevention & control , Forecasting , Models, Statistical
16.
Elife ; 5: e12852, 2016 Jan 18.
Article in English | MEDLINE | ID: mdl-26780669

ABSTRACT

A model based on shoaling fish suggests how a group can show decision-making properties beyond those of any one individual.


Subject(s)
Behavior, Animal , Decision Making , Fishes/physiology , Social Behavior , Animals , Models, Biological
17.
J Contemp Dent Pract ; 15(6): 699-704, 2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25825093

ABSTRACT

OBJECTIVE: The purpose of this study was to evaluate the effect of occlusal contact area for loading on the cuspal defection and stress distribution in a first premolar restored with a high elastic modulus restorative material. MATERIALS AND METHODS: The Rhinoceros 4.0 software was used for modeling the three-dimensional geometries of dental and periodontal structures and the inlay restoration. Thus, two different models, intact and restored teeth with three occlusal contact areas, 0.1, 0.5 and 0.75 mm(2), on enamel at the occlusal surface of buccal and lingual cusps. Finite element analysis (FEA) was performed with the program ANSYS (Workbench 13.0), which generated a mesh with tetrahedral elements with greater refinement in the regions of interest, and was constrained at the bases of cortical and trabecular bone in all axis and loaded with 100 N normal to each contact area. RESULTS: To analysis of maximum principal stress, the smaller occlusal contact area showed greater compressive stress in region of load application for both the intact and inlay restored tooth. However, tensile stresses at the occlusal isthmus were similar for all three tested occlusal contact areas (60 MPa). To displacement of the cusps was higher for teeth with inlay (0.46-0.48 mm). For intact teeth, the smaller contact area showed greater displacement (0.10 mm). For teeth with inlays, the displacement of the cusps were similar in all types of occlusal area. CONCLUSION: Cuspal displacement was higher in the restored tooth when compared to the intact tooth, but there were no significant variations even with changes in the occlusal contact area. RELEVANCE CLINICAL: Occlusal contacts have a great influence on the positioning of teeth being able to maintain the position and stability of the mandible. Axial loads would be able to generate more uniform stress at the root presenting a greater concentration of load application in the point and the occlusal surface. Thus, is necessary to analyze the relationship between these occlusal contacts as dental wear and subsequent occlusal interferences.


Subject(s)
Bicuspid/anatomy & histology , Bite Force , Dental Occlusion , Dental Porcelain/chemistry , Tooth Crown/anatomy & histology , Aluminum Silicates/chemistry , Biomechanical Phenomena , Computer Simulation , Computer-Aided Design , Dental Enamel/anatomy & histology , Elastic Modulus , Finite Element Analysis , Humans , Imaging, Three-Dimensional/methods , Inlays , Materials Testing , Models, Biological , Potassium Compounds/chemistry , Stress, Mechanical , Surface Properties
18.
J Contemp Dent Pract ; 15(6): 735-9, 2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25825099

ABSTRACT

BACKGROUND: Given the benefits of radiographic cephalometric studies in determining patterns of dental-skeletal-facial normality in orthodontics, the aim of this study was to investigate the association between mandibular dental arch shape and cross-sectional and vertical facial measurements. MATERIALS AND METHODS: It was analyzed plaster casts and teleradiographs in frontal and lateral norm belonging to 50 individuals, aged between 15 and 19 years, with no previous history of orthodontic treatment and falling into four of the six Andrews's occlusion keys. The plaster models were scanned (3D) and the images of the dental arches were classified subjectively as oval, triangular and quadrangular by three calibrated examiners, with moderate inter-examiner agreement (Kappa = 0.50). After evaluation of the method error by paired t test (p > 0.05), it was carried out the analysis of cross-sectional and vertical facial measurements to be compared to the shape of the dental arch. Data were subjected to one-way analysis of variance with a significance level of 5%. RESULTS: When the VERT index was compared with the three arch shapes, no measurement showed statistically significant differences (p > 0.05): triangular (0.54); oval (0.43); and quadrangular (0.73); as well as there were no differences (p > 0.05) in the widths of the face (141.20; 141.26; 143.27); maxilla (77.27; 77.57; 78.59) and mandible (105.13; 103.96; 104.28). CONCLUSION: It can be concluded that there was no correlation between different shapes of the mandibular dental arch and the cross-sectional and vertical facial measurements investigated.


Subject(s)
Anatomy, Cross-Sectional/methods , Cephalometry/methods , Dental Arch/anatomy & histology , Face/anatomy & histology , Mandible/anatomy & histology , Vertical Dimension , Adolescent , Chin/anatomy & histology , Chin/diagnostic imaging , Dental Arch/diagnostic imaging , Ear Canal/anatomy & histology , Ear Canal/diagnostic imaging , Face/diagnostic imaging , Female , Humans , Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Male , Mandible/diagnostic imaging , Mandibular Condyle/anatomy & histology , Mandibular Condyle/diagnostic imaging , Maxilla/anatomy & histology , Maxilla/diagnostic imaging , Models, Dental , Nasal Bone/anatomy & histology , Nasal Bone/diagnostic imaging , Nose/anatomy & histology , Nose/diagnostic imaging , Orbit/anatomy & histology , Orbit/diagnostic imaging , Pterygopalatine Fossa/anatomy & histology , Pterygopalatine Fossa/diagnostic imaging , Radiography , Skull Base/anatomy & histology , Skull Base/diagnostic imaging , Young Adult
19.
J Contemp Dent Pract ; 15(6): 761-5, 2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25825104

ABSTRACT

AIM: To evaluate the proliferative potential and the cell proliferation rate of odontogenic epithelial cells. MATERIALS AND METHODS: Forty-two cases of pericoronal follicles of impacted third molars were submitted to silver impregnation technique for quantification of argyrophilic nucleolar organizer regions (AgNOR) and immunohistochemical staining for EGFR and Ki-67. For AgNOR quantification, the mean number of active nucleolar organizer regions per nucleus (mAgNOR) and the percentage of cells with 1, 2, 3 and 4 or more AgNORs per nucleus (pAgNOR) were quantified. Ki-67 immunolabeling was quantified, whereas for EGFR, a descriptive analysis of staining patterns (membrane, cytoplasm or membrane + cytoplasm positivity) was performed. We evaluated the reduced epithelium of the enamel organ and/or islands of odontogenic epithelium present in the entire connective tissue. RESULTS: mAgNOR were 1.43 (1.0-2.42) and were significantly different among pericoronary follicles from upper and lower teeth (p = 0.041). Immunostaining of Ki-67 was negative in all cases. EGFR immunolabeling was found mainly in the cytoplasm and was more intense in islands and cords when compared to reduced epithelium of the enamel organ. CONCLUSION: Odontogenic epithelial cells of some pericoronal follicles have proliferative potential, suggesting their association with the development of odontogenic lesions. CLINICAL SIGNIFICANCE: The authors suggest that nonerupted, especially of the lower teeth, should be monitored and if necessary removed.


Subject(s)
Dental Sac/cytology , Odontogenesis/physiology , Adolescent , Adult , Antigens, Nuclear/analysis , Cell Membrane/ultrastructure , Cell Nucleus/ultrastructure , Cell Proliferation , Cytoplasm/ultrastructure , Dental Sac/ultrastructure , Enamel Organ/cytology , Enamel Organ/ultrastructure , Epithelial Cells/physiology , Epithelial Cells/ultrastructure , ErbB Receptors/analysis , Female , Humans , Immunohistochemistry , Ki-67 Antigen/analysis , Male , Nucleolus Organizer Region/ultrastructure , Young Adult
20.
J Contemp Dent Pract ; 15(6): 770-4, 2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25825106

ABSTRACT

AIM: This clinical report presents a new method for retrieving separated instruments from the root canal with minimally invasive procedures. BACKGROUND: The presence of separated instrument in root canal may interfere in the endodontic treatment prognosis. There are several recommended methods to retrieve separated instruments, but some are difficult in clinically practice. CASE REPORT: This study describes two cases of separated instrument removal from the root canal using a stainless-steel prepared needle associated with a K-file. Case 1 presented a fractured gutta-percha condenser within the mandibular second premolar, it was separated during incorrect intracanal medication calcium hydroxide placement. Case 2 had a fractured sewing needle within the upper central incisor that the patient used to remove food debris from the root canal. After cervical preparation, the fractured instruments were fitted inside a prepared needle and then an endodontic instrument (#25 K-file) was adapted with clockwise turning motion between the needle inner wall and the fragment. CONCLUSION: The endodontic or atypical nonendodontic separated instrument may be easily pull on of the root canal using a single and low cost device. CLINICAL SIGNIFICANCE: The methods for retrieving separated instruments from root canal are difficult and destructive procedures. The present case describes a simple method to solve this problem.


Subject(s)
Dental Pulp Cavity/pathology , Foreign Bodies/therapy , Root Canal Preparation/instrumentation , Calcium Hydroxide/administration & dosage , Child , Equipment Failure , Humans , Male , Middle Aged , Needles , Retreatment , Root Canal Irrigants/administration & dosage , Stainless Steel/chemistry
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