Radiopacity and flow of different endodontic sealers

The present study evaluated the radiopacity and flow of different endodontic sealers: AH Plus, Endo CPM, MTA Fillapex, Sealapex, Epiphany, and Epiphany SE. For the radiopacity test, six specimens measuring 10mm in diameter and 1mm in thickness were fabricated from each material. They were radiographed on an occlusal film alongside an aluminum step wedge. Radiographs were digitized to determine the radiopacity equivalence in millimeters of aluminum. To evaluate the flow, a 120 g load was placed on top of a glass slab containing 0.05 } 0.005ml of sealer. The diameters of each material were measured (mm) with a caliper and samples were photographed. Digitized images were analyzed using the UTHSCSA Image Tool for Windows software, to determine the sealer area (mm2). Data were submitted to ANOVA and Tukey's test at 5% significance. AH Plus and Epiphany SE presented the greatest radiopacity (12.5 mm Al and 12.0 mm Al, respectively) (p>0.05), followed by Epiphany (9.6 mm Al) and Fillapex (8.9 mm Al). Endo CPM (5.46 mm Al) and Sealapex (5.51 mm Al) presented lower radiopacity. MTA Fillapex presented significantly higher values of flow than other sealers (33.11 mm and 844.9 mm2). AH Plus, Epiphany, and Epiphany SE had similar values. Endo CPM (21.05 mm and 342.8 mm2) and Sealapex (19.98 mm and 352.5 mm2) presented the lowest flow values (p>0.05). All sealers presented radiopacity and flow values according to ISO and ANSI/ADA recommendations.

Push-out bond strength of calcium hydroxide and mineral trioxide aggregate based sealers

The adhesiveness of six root canal sealers: Acroseal, Endo CPM, Epiphany, White MTA, Sealapex and Sealer 26 to dentin, was evaluated in a push-out test design. Methods: Twenty eight roots of freshly extracted teeth were gauged with a size 5 Largo drill. With a cutting machine slices of 2 mm were prepared, rinsed with 5.25% NaOCl and a final rinse with 17% EDTA, dried and filled with one of the sealers. After setting their bond strength was measured in a mechanical testing machine. The data were statistically analyzed by using a One Way ANOVA and post hoc Tukey test. Results: The mean and standard deviation from values of bond strength was: Sealapex 2.2±0.4; Endo CPM 3.8±1.3; White MTA 6.0±1.4; Epiphany 10.9±2.6; Sealer 26 12.3±2.3; and Acroseal 12.2±1.4. Acroseal, Sealer 26 and Epiphany presented a significantly (P<0.01) greater bond strength compared with the other sealers. Also White MTA showed higher adhesiveness compared with Endo CPM and Sealapex (P<0.01). Conclusion: The bond strength between endodontic sealers and root dentin was maximal when Acroseal, Sealer 26 and Epiphany were used; Sealapex e Endo CPM, in turn, presented the lowest bond strength mean values.

Nano-displacement measurements of a new piezoelectric flextensional actuator by using a high dynamic range interferometry homodyne method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Atividade antimicrobiana de cimentos endodônticos

The antimicrobial activity is a fundamental property of root-canal sealers due to persistence of residual microorganisms in the root canal system, even after the chemo-mechanical preparation and using of intracanal dressing. The aim of this study is to review the literature about the antimicrobial properties of some of the main root-canal sealers. Although there is controversy regarding this property, probably due to differences in the methodologies used in the studies, it was concluded that the sealers with the best antimicrobial activity were (in ascending order): Endofill, Ketac Endo, Sealapex, AH Plus, Endo CPM Sealer, Sealer 26 and Epiphany. Activ GP still needs scientific research to evaluate this property.

Efeito do cimento Portland modificado e MTA na viabilidade de fibroblastos e produção de ciocinas

Objetivo: o objetivo desse estudo foi investigar os efeitos da nova formulação do Cimento Portland (CPM) comparando-o ao MTA Angelus na viabilidade celular e liberação de IL-1b e IL-6 em fibroblastos de rato. Métodos: tubos de polietileno preenchidos com os materiais estudados foram colocados em placas de cultura celular de 24 poços com fibroblastos de rato. Tubos vazios foram utilizados como controle. Após 24 horas, ensaio MTT foi utilizado para avaliar a viabilidade celular. Para o ensaio de citocinas, fibroblastos de ratos foram incubados em placas de fundo plano de 24 poços com discos dos materiais no fundo, ou sem material, como controle. Após 24 horas, o meio de cultura foi coletado para a avaliação das citocinas pelo ELISA. Resultados: o CPM e MTA Angelus não inibiram a viabilidade celular. Ambos os materiais induziram liberação de IL-6 e IL-1b e a quantidade foi estatisticamente significativa se comparada ao grupo controle. Conclusão: ambos os materiais não foram citotóxicos em cultura de fibroblastos e induziram a liberação de IL-6 e IL-1b.

Characterization of atmospheric aerosols in the city of So Paulo, Brazil: comparisons between polluted and unpolluted periods

The objective of this study was to determine the size and composition of atmospheric aerosols in the downtown area of the city of So Paulo, Brazil, for a polluted and an unpolluted period. Aerosols were sampled with a portable air sampler (PAS), Micro-Orifice Uniform Deposit Impactor (MOUDI), and Scanning Mobility Particle Sizer. At the study site, air quality is poor, especially during the winter, high concentrations of pollutants being emitted primarily by the light- and heavy-duty vehicle fleet. We analyzed mass, black carbon (BC), Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sn, Zr, and Pb. During the polluted period, diurnal PM(10) was higher than nocturnal PM(10), whereas the inverse was true during the unpolluted period. The FPM was rich in BC, S, and Pb, whereas CPM was rich in Al, Si, Ca, Ti, and Fe. Mass balance was performed by category: ammonium sulfate, sodium chloride, crustal material, BC, and other. The PAS-determined FPM was mainly BC. The MOUDI-determined FPM crustal material explained more mass than did ammonium sulfate and BC during the polluted period, whereas ammonium sulfate had the largest mass during the unpolluted period. Crustal material was the major CPM component, followed by ammonium sulfate and BC. During the unpolluted period, FPM concentrations were lower, whereas those of ammonium sulfate were relatively higher, especially at night, and particle number was inversely proportional to particle size. Aerosol growth was more intense during the polluted period.

Vitamin C and Vitamin E in Prevention of Nonalcoholic Fatty Liver Disease (NAFLD) in Choline Deficient Diet Fed Rats

Abstract Aim Oxidative stress has been implicated in the pathogenesis of Nonalcoholic Fatty Liver Disease (NAFLD). Vitamin C and vitamin E are known to react with reactive oxygen species (ROS) blocking the propagation of radical reactions in a wide range of oxidative stress situations. The potential therapeutic efficacy of antioxidants in NAFLD is unknown. The aim of this study was to evaluate the role of antioxidant drugs (vitamin C or vitamin E) in its prevention. Methods Fatty liver disease was induced in Wistar rats by choline-deficient diet for four weeks. The rats were randomly assigned to receive vitamin E (n = 6) – (200 mg/day), vitamin C (n = 6) (30 mg/Kg/day) or vehicle orally. Results In the vehicle and vitamin E-treated rats, there were moderate macro and microvesicular fatty changes in periportal area without inflammatory infiltrate or fibrosis. Scharlach stain that used for a more precise identification of fatty change was strong positive. With vitamin C, there was marked decrease in histological alterations. Essentially, there was no liver steatosis, only hepatocellular ballooning. Scharlach stain was negative. The lucigenin-enhanced luminescence was reduced with vitamin C (1080 ± 330 cpm/mg/minx103) as compared to those Vitamin E and control (2247 ± 790; 2020 ± 407 cpm/mg/minx103, respectively) (p < 0.05). Serum levels of aminotransferases were unaltered by vitamin C or vitamin E. Conclusions 1) Vitamin C reduced oxidative stress and markedly inhibited the development of experimental liver steatosis induced by choline-deficient diet ; 2)Vitamin E neither prevented the development of fatty liver nor reduced the oxidative stress in this model.

Do Central Hypersensitivity and Altered Pain Modulation Predict the Course of Chronic Low Back and Neck Pain?

OBJECTIVES:: Widespread central hypersensitivity and altered conditioned pain modulation (CPM) have been documented in chronic pain conditions. Information on their prognostic values is limited. This study tested the hypothesis that widespread central hypersensitivity (WCH) and altered CPM, assessed during the chronic phase of low back and neck pain, predict poor outcome. METHODS:: A total of 169 consecutive patients with chronic low back or neck pain, referred to the pain clinic during 1 year, were analyzed. Pressure pain tolerance threshold at the second toe and tolerance time during cold pressor test at the hand assessed WCH. CPM was measured by the change in pressure pain tolerance threshold (test stimulus) after cold pressor test (conditioning stimulus). A structured telephone interview was performed 12 to 15 months after testing to record outcome parameters. Linear regression models were used, with average and maximum pain intensity of the last 24 hours at follow-up as endpoints. Multivariable analyses included sex, age, catastrophizing scale, Beck Depression Inventory, pain duration, intake of opioids, and type of pain syndrome. RESULTS:: Statistically significant reductions from baseline to follow-up were observed in pain intensity (P<0.001). No evidence for an association between the measures of WCH or CPM and intensity of chronic pain at follow-up was found. DISCUSSION:: A major predictive value of the measures that we used is unlikely. Future studies adopting other assessment modalities and possibly standardized treatments are needed to further elucidate the prognostic value of WCH and altered CPM in chronic pain.

Daptomycin produces an enhanced bactericidal activity compared to ceftriaxone, measured by [3H]choline release in the cerebrospinal fluid, in experimental meningitis due to a penicillin-resistant pneumococcal strain without lysing its cell wall

Daptomycin monotherapy was superior to ceftriaxone monotherapy and was highly efficacious in experimental pneumococcal meningitis, sterilizing the cerebrospinal fluid (CSF) of three of three rabbits after 4 to 6 h. With daptomycin therapy only a negligible release of [(3)H]choline as marker of cell wall lysis was detectable in the CSF, peaking around 250 cpm/min after 4 h, compared to a peak of around 2,400 cpm/min after 4 to 6 h for the ceftriaxone-treated rabbits.

MIMO waveform design using continuous phase modulation

Hybrid MIMO Phased-Array Radar (HMPAR) is an emerging technology that combines MIMO (multiple-in, multiple-out) radar technology with phased-array radar technology. The new technology is in its infancy, but much of the theoretical work for this specific project has already been completed and is explored in great depth in [1]. A brief overview of phased-array radar systems, MIMO radar systems, and the HMPAR paradigm are explored in this paper. This report is the culmination of an effort to support research in MIMO and HMPAR utilizing a concept called intrapulse beamscan. Using intrapulse beamscan, arbitrary spatial coverage can be achieved within one MIMO beam pulse. Therefore, this report focuses on designing waveforms for MIMO radar systems with arbitrary spatial coverage using that phenomenon. With intrapulse beamscan, scanning is done through phase-modulated signal design within one pulse rather than phase-shifters in the phased array over multiple pulses. In addition to using this idea, continuous phase modulation (CPM) signals are considered for their desirable peak-to-average ratio property as well as their low spectral leakage. These MIMO waveforms are designed with three goals in mind. The first goal is to achieve flexible spatial coverage while utilizing intrapulse beamscan. As with almost any radar system, we wish to have flexibility in where we send our signal energy. The second goal is to maintain a peak-to-average ratio close to 1 on the envelope of these waveforms, ensuring a signal that is close to constant modulus. It is desired to have a radar system transmit at the highest available power; not doing so would further diminish the already very small return signals. The third goal is to ensure low spectral leakage using various techniques to limit the bandwidth of the designed signals. Spectral containment is important to avoid interference with systems that utilize nearby frequencies in the electromagnetic spectrum. These three goals are realized allowing for limitations of real radar systems. In addition to flexible spatial coverage, the report examines the spectral properties of utilizing various space-filling techniques for desired spatial areas. The space-filling techniques examined include Hilbert/Peano curves and standard raster scans.

Comparison of calcium analysis, longitudinal microradiography and profilometry for the quantitative assessment of erosion in dentine

Erosion of dentine causes mineral dissolution, while the organic compounds remain at the surface. Therefore, a determination of tissue loss is complicated. Established quantitative methods for the evaluation of enamel have also been used for dentine, but the suitability of these techniques in this field has not been systematically determined. Therefore, this study aimed to compare longitudinal microradiography (LMR), contacting (cPM) and non-contacting profilometry (ncPM), and analysis of dissolved calcium (Ca analysis) in the erosion solution. Results are discussed in the light of the histology of dentine erosion. Erosion was performed with 0.05 M citric acid (pH 2.5) for 30, 60, 90 or 120 min, and erosive loss was determined by each method. LMR, cPM and ncPM were performed before and after collagenase digestion of the demineralised organic surface layer, with an emphasis on moisture control. Scanning electron microscopy was performed on randomly selected specimens. All measurements were converted into micrometres. Profilometry was not suitable to adequately quantify mineral loss prior to collagenase digestion. After 120 min of erosion, values of 5.4 +/- 1.9 microm (ncPM) and 27.8 +/- 4.6 microm (cPM) were determined. Ca analysis revealed a mineral loss of 55.4 +/- 11.5 microm. The values for profilometry after matrix digestion were 43.0 +/- 5.5 microm (ncPM) and 46.9 +/- 6.2 (cPM). Relative and proportional biases were detected for all method comparisons. The mineral loss values were below the detection limit for LMR. The study revealed gross differences between methods, particularly when demineralised organic surface tissue was present. These results indicate that the choice of method is critical and depends on the parameter under study.

The prevalence of widespread central hypersensitivity in chronic pain patients

BACKGROUND Chronic pain is associated with generalized hypersensitivity and impaired endogenous pain modulation (conditioned pain modulation; CPM). Despite extensive research, their prevalence in chronic pain patients is unknown. This study investigated the prevalence and potential determinants of widespread central hypersensitivity and described the distribution of CPM in chronic pain patients. METHODS We examined 464 consecutive chronic pain patients for generalized hypersensitivity and CPM using pressure algometry at the second toe and cold pressor test. Potential determinants of generalized central hypersensitivity were studied using uni- and multivariate regression analyses. Prevalence of generalized central hypersensitivity was calculated for the 5th, 10th and 25th percentile of normative values for pressure algometry obtained by a previous large study on healthy volunteers. CPM was addressed on a descriptive basis, since normative values are not available. RESULTS Depending on the percentile of normative values considered, generalized central hypersensitivity affected 17.5-35.3% of patients. 23.7% of patients showed no increase in pressure pain threshold after cold pressor test. Generalized central hypersensitivity was more frequent and CPM less effective in women than in men. Unclearly classifiable pain syndromes showed higher frequencies of generalized central hypersensitivity than other pain syndromes. CONCLUSIONS Although prevalent in chronic pain, generalized central hypersensitivity is not present in every patient. An individual assessment is therefore required in order to detect altered pain processing. The broad basic knowledge about central hypersensitivity now needs to be translated into concrete clinical consequences, so that patients can be offered an individually tailored mechanism-based treatment.

Reactivity to Accelerometer Measurement of Children and Adolescents

PURPOSE: Awareness of being monitored can influence participants' habitual physical activity (PA) behavior. This reactivity effect may threaten the validity of PA assessment. Reports on reactivity when measuring the PA of children and adolescents have been inconsistent. The aim of this study was to investigate whether PA outcomes measured by accelerometer devices differ from measurement day to measurement day and whether the day of the week and the day on which measurement started influence these differences. METHODS: Accelerometer data (counts per minute [cpm]) of children and adolescents (n = 2081) pooled from eight studies in Switzerland with at least 10 h of daily valid recording were investigated for effects of measurement day, day of the week, and start day using mixed linear regression. RESULTS: The first measurement day was the most active day. Counts per minute were significantly higher than on the second to the sixth day, but not on the seventh day. Differences in the age-adjusted means between the first and consecutive days ranged from 23 to 45 cpm (3.6%-7.1%). In preschoolchildren, the differences almost reached 10%. The start day significantly influenced PA outcome measures. CONCLUSIONS: Reactivity to accelerometer measurement of PA is likely to be present to an extent of approximately 5% on the first day and may introduce a relevant bias to accelerometer-based studies. In preschoolchildren, the effects are larger than those in elementary and secondary schoolchildren. As the day of the week and the start day significantly influence PA estimates, researchers should plan for at least one familiarization day in school-age children and randomly assign start days.

Is the conditioned pain modulation paradigm reliable? A test-retest assessment using the nociceptive withdrawal reflex.

The aim of this study was to determine the reliability of the conditioned pain modulation (CPM) paradigm assessed by an objective electrophysiological method, the nociceptive withdrawal reflex (NWR), and psychophysical measures, using hypothetical sample sizes for future studies as analytical goals. Thirty-four healthy volunteers participated in two identical experimental sessions, separated by 1 to 3 weeks. In each session, the cold pressor test (CPT) was used to induce CPM, and the NWR thresholds, electrical pain detection thresholds and pain intensity ratings after suprathreshold electrical stimulation were assessed before and during CPT. CPM was consistently detected by all methods, and the electrophysiological measures did not introduce additional variation to the assessment. In particular, 99% of the trials resulted in higher NWR thresholds during CPT, with an average increase of 3.4 mA (p<0.001). Similarly, 96% of the trials resulted in higher electrical pain detection thresholds during CPT, with an average increase of 2.2 mA (p<0.001). Pain intensity ratings after suprathreshold electrical stimulation were reduced during CPT in 84% of the trials, displaying an average decrease of 1.5 points in a numeric rating scale (p<0.001). Under these experimental conditions, CPM reliability was acceptable for all assessment methods in terms of sample sizes for potential experiments. The presented results are encouraging with regards to the use of the CPM as an assessment tool in experimental and clinical pain. Trial registration: Clinical Trials.gov NCT01636440.

Bayesian inference and its application to meta-analysis of epidemiologic data

In Part One, the foundations of Bayesian inference are reviewed, and the technicalities of the Bayesian method are illustrated. Part Two applies the Bayesian meta-analysis program, the Confidence Profile Method (CPM), to clinical trial data and evaluates the merits of using Bayesian meta-analysis for overviews of clinical trials.^ The Bayesian method of meta-analysis produced similar results to the classical results because of the large sample size, along with the input of a non-preferential prior probability distribution. These results were anticipated through explanations in Part One of the mechanics of the Bayesian approach. ^