RESUMO

INTRODUCTION: Developmental Defects of Enamel (DDEs) comprise qualitative and/or quantitative changes to the enamel during amelogenesis. The aetiology of DDE remains inconclusive. AIM: To determine the association of pre, peri, and postnatal factors with the presence of DDE. DESIGN: Cross-sectional study with 353 children (8 to 11 years-old) in a Brazilian town. METHODS: One calibrated dentist assessed DDE using the Developmental Defects of Enamel Index and a questionnaire collected medical and sociodemographic data. MAIN OUTCOMES: Children with at least one type of DDE were categorized into the DDE group. Subtypes of DDE were also recorded. RESULTS: 63.1% of children had at least one type of DDE. Diffuse opacity was present in 36.7%, demarcated opacity in 14.8%, and hypoplasia in 5.83% of the children. In multivariate analysis, demarcated opacities and hypoplasia were associated with birth weight ⟨ 2500g (OR = 4.82; 95% CI 1.23-1.95). CONCLUSION: Low birth weight predicted DDE.

Assuntos

Hipoplasia do Esmalte Dentário , Brasil/epidemiologia , Criança , Estudos Transversais , Esmalte Dentário , Hipoplasia do Esmalte Dentário/epidemiologia , Humanos , Prevalência , Fatores de Risco

RESUMO

AIM: To evaluate the association between the promoter region of defensin beta 1 (DEFB1) genetic polymorphisms and persistent apical periodontitis (PAP) in Brazilian patients. METHODOLOGY: Seventy-three patients with post-treatment PAP (PAP group) and 89 patients with root filled teeth with healed and healthy periradicular tissues (healed group) were included (all teeth had apical periodontitis lesions at the beginning of the treatment). Patients who had undergone at least 1 year of follow-up after root canal treatment were recalled, and their genomic DNA was extracted from saliva. Two single nucleotide polymorphisms (SNPs) in DEFB1 at the g. -52G>A (rs1799946) and g. -20G>A (rs11362) positions were analysed using real-time polymerase chain reaction. The chi-squared test was performed, and the odds ratios were calculated using Epi Info 3.5.2. Logistic regression analysis in the codominant model, using the time of follow-up as a variable, was used to evaluate the SNP-SNP interaction. All tests were performed with an established alpha of 0.05 (P = 0.05). RESULTS: For the rs11362 polymorphism in the codominant and recessive models, patients who carried two copies of the T allele had a significantly lower risk of developing PAP (P = 0.040 and P = 0.031, respectively). For the rs1799946 polymorphism in DEFB1 in the codominant and recessive models, carrying one copy of the T allele significantly increased the risk of developing PAP (P = 0.007 and P = 0.031, respectively). In the logistic regression, both polymorphisms were associated with PAP as well as the SNP-SNP interaction (P < 0.0001). CONCLUSIONS: Polymorphisms in DEFB1 genes were associated with the development of post-treatment persistent apical periodontitis.

Assuntos

Periodontite Periapical , beta-Defensinas , Brasil , Predisposição Genética para Doença , Genótipo , Humanos , Periodontite Periapical/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , beta-Defensinas/genética

RESUMO

With an increasing number of international journeys occurring daily, there is also an increase in the need for appropriate medical advice for patients who will undertake such travel. In this context, the lupus patient presents a great challenge to the rheumatologist. However, the demand for such information by patients is low, and it has proven difficult for the medical community to adequately provide it. In this article, we carried out a literature review of the medical recommendations made for the lupus patient in order to guide the rheumatologist through the topic of travel medicine.

Assuntos

Lúpus Eritematoso Sistêmico , Reumatologia , Viagem , Vacinação , Humanos , Guias de Prática Clínica como Assunto , Medicina de Viagem/educação

RESUMO

AIM: To investigate the smallest dentine thickness in mesial canals of mandibular molars along the cervical and middle thirds of the root by means of a micro-computed tomographic (micro-CT) technology and digital image analysis. METHODOLOGY: Fifty mesial roots of mandibular molars having two independent canals (mesiobuccal and mesiolingual), in the coronal and middle levels, were selected and scanned in a micro-CT device. After reconstruction procedures, approximately 468 slices per root covering the 7 mm below the furcation area of the mesial root were analysed to measure the smallest dentine thickness (danger zone [DZ]) in each slice from both distal and mesial regions of the mesial canals by an automatic segmentation process. RESULTS: The DZ values in the mesiobuccal canals varied from 0.67 to 1.93 mm, with an average of 1.13 ± 0.21 mm. For the mesiolingual canals, the DZ varied from 0.77 to 1.89 mm with an average of 1.10 ± 0.21 mm. There was no correspondence in the DZ between the mesiobuccal and mesiolingual canals at the same cross-sectional level in 71% of the specimens. Moreover, the smallest dentine thickness was towards the mesial region of the roots in 22% and 18% of the mesiolingual and mesiobuccal canals, respectively. (Figs 1 and 2 CONCLUSIONS: The smallest dentine thickness was on the mesial plane of the roots in about 40% of the canals. The vertical location of the DZ in relation to the furcation area was in the middle third of the root.

Assuntos

Mandíbula , Dente Molar , Estudos Transversais , Cavidade Pulpar , Dentina , Raiz Dentária , Microtomografia por Raio-X

RESUMO

AIM: To compare the efficiency of M-Wire Reciproc and Reciproc Blue instruments in the removal of root filling material and in their ability to regain apical patency through micro-computed tomographic (micro-CT) analysis. METHODOLOGY: Ten anatomically matched pairs of teeth, with a single oval-shaped straight canal, were selected and scanned in a micro-CT device. The root canals were prepared with M-Wire Reciproc R25 instruments and filled with gutta-percha and AH Plus sealer. The root canals were then randomly allocated into two groups (n = 10), according to the instrument used: M-Wire Reciproc and Reciproc Blue. The canals were retreated up to instrument sizes 25 and then 40 in both groups. The surface area and volume of residual filling material were assessed using micro-CT imaging after the retreatment procedures. The time required to remove the root fillings was recorded. Data were analysed statistically using t-test with a significance level of 5%. RESULTS: No significant difference (P > 0.05) was observed between the instruments in terms of the volume of residual root filling material. Apical enlargement from size 25 to 40 significantly improved the removal of filling materials (P < 0.05). It was possible to regain apical patency in all specimens from both M-Wire Reciproc and Reciproc Blue groups. No difference was observed in the time required to perform the retreatment between the instruments. CONCLUSIONS: Both M-Wire Reciproc and Reciproc Blue instruments were effective in removing filling materials from oval-shaped straight canals. Apical patency was reestablished in all specimens.

Assuntos

Instrumentos Odontológicos , Materiais Restauradores do Canal Radicular/química , Obturação do Canal Radicular/instrumentação , Obturação do Canal Radicular/métodos , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Anatomia Transversal , Ligas Dentárias/química , Cavidade Pulpar/diagnóstico por imagem , Desenho de Equipamento , Guta-Percha/química , Humanos , Incisivo/anatomia & histologia , Incisivo/diagnóstico por imagem , Incisivo/cirurgia , Mandíbula , Teste de Materiais , Níquel/química , Retratamento , Irrigantes do Canal Radicular , Hipoclorito de Sódio/química , Propriedades de Superfície , Titânio , Ápice Dentário/anatomia & histologia , Microtomografia por Raio-X/métodos

RESUMO

The number of substances nominally listed in the prohibited list of the World Anti-Doping Agency increases each year. Moreover, many of these substances do not have a single analytical target and must be monitored through different metabolites, artifacts, degradation products, or biomarkers. A new analytical method was developed and validated for the simultaneous analysis of peptides and organic molecules using a single sample preparation and LC-Q-HRMS detection. The simultaneous analysis of 450 target molecules was performed after cleanup on a mixed-mode solid-phase extraction cartridge, combined with untreated urine. The cleanup solvent and reconstitution solvent were the most important parameters for achieving a comprehensive sample preparation approach. A fast chromatographic run based on a multistep gradient was optimized under different flows; the detection of all substances without isomeric coelution was achieved in 11 minutes, and the chromatographic resolution was considered a critical parameter, even in high-resolution mass spectrometry detection. The mass spectrometer was set to operate by switching between positive and negative ionization mode for FULL-MS, all-ion fragmentation, and FULL-MS/MS2 . The suitable parameters for the curved linear trap (c-trap) conditions were determined and found to be the most important factors for the development of the method. Only FULL-MS/MS2 enables the detection of steroids and peptides at concentrations lower than the minimum required performance levels set by World Anti-Doping Agency (1 ng mL-1 ). The combination of the maximum injection time of the ions into the c-trap, multiplexing experiments, and loop count under optimized conditions enabled the method to be applied to over 10 000 samples in only 2 months during the 2016 Rio Summer Olympic and Paralympic Games. The procedure details all aspects, from sample preparation to mass spectrometry detection. FULL-MS data acquisition is performed in positive and negative ion mode simultaneously and can be applied to untargeted approaches.

Assuntos

Peptídeos/análise , Esteroides/análise , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Dopagem Esportivo/prevenção & controle , Humanos , Limite de Detecção , Peptídeos/urina , Extração em Fase Sólida/métodos , Esteroides/urina

RESUMO

We report on the existence of two different regimes in one-step Ag-seeded InP nanowire growth. The vapor-liquid-solid-mechanism is present at larger In precursor flows and temperatures, ∼500 °C, yielding high aspect ratio and pure wurtzite InP nanowires with a semi-spherical metal particle at the thin apex. Periodic diameter oscillations can be achieved under extreme In supersaturations at this temperature range, showing the presence of a liquid catalyst. However, under lower temperatures and In precursor flows, large diameter InP nanowires with mixed wurtzite/zincblende segments are obtained, similarly to In-assisted growth. Chemical composition analysis suggest that In-rich droplet formation is catalyzed at the substrate surface via Ag nanoparticles; this process might be facilitated by the sulfur contamination detected in these nanoparticles. Furthermore, part of the original Ag nanoparticle remains solid and is embedded inside the actual catalyst, providing an in situ method to switch growth mechanisms upon changing In precursor flow. Nevertheless, our Ag-seeded InP nanowires exhibit overall optical emission spectra consistent with the observed structural properties and similar to Au-catalyzed InP nanowires. We thus show that Ag nanoparticles may be a suitable replacement for Au in InP nanowire growth.

RESUMO

InAs nanowires grown by vapor-liquid-solid (VLS) method are investigated by photoluminescence. We observe that the Fermi energy of all samples is reduced by ∼20 meV when the size of the Au nanoparticle used for catalysis is increased from 5 to 20 nm. Additional capping with a thin InP shell enhances the optical emission and does not affect the Fermi energy. The unexpected behavior of the Fermi energy is attributed to the differences in the residual donor (likely carbon) incorporation in the axial (low) and lateral (high incorporation) growth in the VLS and vapor-solid (VS) methods, respectively. The different impurity incorporation rate in these two regions leads to a core/shell InAs homostructure. In this case, the minority carriers (holes) diffuse to the core due to the built-in electric field created by the radial impurity distribution. As a result, the optical emission is dominated by the core region rather than by the more heavily doped InAs shell. Thus, the photoluminescence spectra and the Fermi energy become sensitive to the core diameter. These results are corroborated by a theoretical model using a self-consistent method to calculate the radial carrier distribution and Fermi energy for distinct diameters of Au nanoparticles.

RESUMO

AIM: To evaluate and compare the push-out bond strength of MTA Fillapex (Angelus, Londrina, Brazil) and iRoot SP (Innovative BioCeramix Inc., Vancouver, Canada) to the dentine walls of root canals. AH Plus (Dentsply DeTrey, Konstaz, Germany) and MTA (Angelus, Londrina, Brazil) were used as reference materials. METHODOLOGY: Sixty extracted human single-rooted teeth were selected. After standardized canal preparation and irrigation, the canals were dried with paper points and filled with one of four sealers: AH Plus, iRoot SP, MTA and MTA Fillapex. Roots were sectioned, and push-out tests were performed. The values of bond strength were analysed using the Kruskal-Wallis test. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05 for the analyses. RESULTS: All specimens had measurable adhesion to root dentine and no premature failure occurred. There were significant differences amongst materials (P = 0.000). MTA-filled specimens had higher push-out bond strength values (P = 0.000). AH Plus had significantly higher bond strength than both Fillapex and iRoot SP (P = 0.000). Both Fillapex and iRoot SP had the lowest push-out bond strength amongst all experimental groups (P = 0.000). No difference occurred between the two calcium silicate-based root canal sealers (P = 0.265). CONCLUSION: The adhesion to root dentine associated with newer calcium silicate-based sealers was compromised even when well-monitored laboratory conditions were used.

Assuntos

Compostos de Alumínio/química , Compostos de Cálcio/química , Colagem Dentária , Dentina , Óxidos/química , Materiais Restauradores do Canal Radicular/química , Silicatos/química , Cavidade Pulpar , Análise do Estresse Dentário , Combinação de Medicamentos , Humanos , Teste de Materiais

RESUMO

Semiconductor nanowires oriented along the [211] direction usually present twins parallel to their axis. For group IV nanowires this kind of twin allows the formation of a catalyst-nanowire interface composed of two equivalent {111} facets. For III-V nanowires, however, the twin will generate two facets with different polarities. In order to keep the <211> orientation stable, a balance in growth rates for these different facets must be reached. We report here the observation of stable, micron-long <211>-oriented InGaP nanowires with a spontaneous core-shell structure. We show that stacking fault formation in the crystal region corresponding to the {111}A facet termination provides a stable NW/NP interface for growth along the <211> direction. During sample cool down, however, the catalyst migrates to a lateral {111}B facet, allowing the growth of branches perpendicular to the initial orientation. In addition to that, we show that the core-shell structure is non-concentric, most likely due to the asymmetry between the facets formed in the NW sidewall; this effect generates stress along the nanowire, which can be relieved through bending.