Preliminary study of the inflammatory response to subcutaneous implantation of three root canal sealers

P>Aim To evaluate the kinetics of the inflammatory tissue response to three root canal sealers using a physicochemical method for quantification of the enhanced vascular permeability and histopathological analysis. Methodology Twenty-eight male Wistar rats randomly assigned to four groups according to the evaluation periods (1, 3, 7 and 14 days) were used to assess the vascular permeability and histopathological reaction to RoekoSeal, AH Plus and Sealapex (new formulation) sealers, using saline and Chloropercha as negative and positive controls, respectively. Seven rats were sacrificed per period. The biocompatibility of the sealers was evaluated spectrophotometrically and histopathologically. Results At day 14, Sealapex produced significantly more inflammatory exudate than AH Plus and RoekoSeal (P < 0.05); however, there was no significant difference between AH Plus and RoekoSeal (P > 0.05). Sealapex (new formulation) was the most irritating sealer, producing severe inflammation with the presence of multinucleated giant cells. RoekoSeal was the most biocompatible sealer, producing the least amount of inflammatory exudate. Conclusions RoekoSeal root canal sealer was biocompatible when implanted in connective tissue.

A scanning electron microscopy study of diseased root surfaces conditioned with EDTA gel plus Cetavlon after scaling and root planing

In the present investigation, a scanning electron microscopy analysis was performed to evaluate the effects of the topical application of ethylenediaminetetraacetic acid (EDTA) gel associated with Cetavlon (EDTAC) in removing the smear layer and exposing collagen fibers following root surface instrumentation. Twenty-eight teeth from adult humans, single rooted and scheduled for extraction due to periodontal reasons, were selected. Each tooth was submitted to manual (scaling and root planing) instrumentation alone or combined with ultrasonic instruments, with or without etching using a 24% EDTAC gel. Following extraction, specimens were processed and examined under a scanning electron microscope. A comparative morphological semi-quantitative analysis was performed; the intensity of the smear layer and the decalcification of cementum and dentinal surfaces were graded in 12 sets using an arbitrary scale ranging from 1 (area covered by a smear layer) to 4 (no smear layer). Root debridement with hand instruments alone or combined with ultrasonic instruments resulted in a similar smear layer covering the root surfaces. The smear layer was successfully removed from the surfaces treated with EDTAC, which exhibited numerous exposed dentinal tubules and collagen fibers. This study supports the hypothesis that manual instrumentation alone or instrumentation combined with ultrasonic instrumentation is unable to remove the smear layer, whereas the subsequent topical application of EDTAC gel effectively removes the smear layer, uncovers dentinal openings and exposes collagen fibers.

Bond strength of fibre glass and carbon fibre posts to the root canal walls using different resin cements

The aim of the study was to evaluate the bond strength of fibre glass and carbon fibre posts in the root canal walls cemented with self-adhesive (RelyX-Unicem) and chemical (Cement-Post) resin cements. Forty maxillary canines were divided into four groups according to the cement and post used and submitted to the push-out test (0.5 mm min(-1)). The data were submitted to statistical analysis (2-way ANOVA, Bonferroni - P < 0.05) and fracture analysis by Scanning Electronic Microscopy. Fibre glass presented the best results when cemented with RelyX-Unicem and Cement-Post (P < 0.05). RelyX-Unicem presented the highest bond strength values for both posts (P < 0.05). Fracture analysis showed predominance of cohesive fracture of post for RelyX-Unicem and adhesive fracture between dentin/cement and mixed for Cement-Post. The bond strength values were significantly affected by the type of post and cement used and the highest values were found for fibre glass posts and RelyX-Unicem.

Effect of Two Restorative Materials on Root Dentine Erosion

This study sought to evaluate the microhardness of root dentine adjacent to glass-ionomer and composite resin restorations after erosive challenge. A crossover study was performed in two phases of 4 consecutive days each. One hundred twelve bovine root dentine slabs were obtained, and standardized box-shaped cavities were prepared at center of each specimen. The prepared cavities were randomly restored with glass-ionomer cement or composite resin. The slabs were randomly assigned among 14 volunteers, which wore intraoral palatal device containing four restored root dentin slabs. Starting on the second day, half of the palatal acrylic devices were immersed extraorally in a lemonade-like carbonated soft drink for 90 s, four times daily for 3 days. Alter 3-day wash-out, dentine slabs restored with the alternative material were placed into palatal appliance and the volunteers started the second phase of this study. After erosive challenges. microhardness measurements were performed. Regardless of the restorative material employed, eroded specimens demonstrated lower microhardness value (p < 0.0001). At eroded condition examined in this study, dentine restored with glass-ionomer cement showed higher microhardness values (p < 0.0001). It may be concluded that the glass-ionomer cement decreases the progression of root dentine erosion at restoration margin. (C) 2010 Wiley Periodicals, Inc J Biomed Mater Res Part B Appl Biomater 93B 304-305, 2010

Information for the diagnosis and treatment of root resorption due to tooth replantation

A favorable prognosis after tooth avulsion depends on some variables, such as the extra-alveolar period and storage medium. Vitality of the periodontal ligament cells is considered a critical factor for a successful outcome without root resorption. The dental surgeon is provided with clinical information and radiographic findings to establish a diagnosis and may rely on current available guidelines. Once trauma has occurred, treatment must be quick and effective, and periodic follow-up must be performed. Clinical, radiographic, and histologic characteristics for each type of root resorption due to tooth replantation are presented, with the aim to provide information for the diagnosis and treatment of healing complications.

Resurrection of Two Species From Synonymy of Anopheles (Nyssorhynchus) strodei Root, and Characterization of a Distinct Morphological Form From the Strodei Complex (Diptera: Culicidae)

Anopheles albertoi Unti and Anopheles arthuri Unti are revived from the synonymy with Anopheles strodei Root, and a distinct morphological form (designated in this study as Anopheles CP Form) from the Strodei Complex of Anopheles (Nyssorhynchus) is characterized. The male genitalia of An. arthuri and An. albertoi are described and illustrated for the first time. An. strodei, An. arthuri, and An. albertoi were first distinguished based on scanning electron microphotos of the eggs, and then each egg type was associated with diagnostic characters of the male genitalia. Identification of Anopheles CP Form was based on morphological characters of the male genitalia, characterized and illustrated in this study. Molecular phylogenetic analysis was most clear when an outgroup was not included, in which case using the nuclear white gene, or the white gene in combination with the mitochondrial cytochrome c oxidase subunit I (COI) gene, clearly separated these four taxa. When Anopheles quadrimaculatus Say and Anopheles stephensi Liston were included as an outgroup, combined white and COI data resolved An. strodei and An. albertoi, whereas An. arthuri was not well resolved. The single sequence of Anopheles CP Form was recovered well separated from other groups in all analyses.

Deep crustal structure of the Parana Basin from receiver functions and Rayleigh-wave dispersion: Evidence for a fragmented cratonic root

The deep crustal structure of the Parana Basin of southern Brazil is investigated by analyzing P- and PP-wave receiver functions at 17 Brazilian Lithosphere Seismic Project stations within the basin. The study area can be described as a typical Paleozoic intracratonic basin that hosts one of the largest Large Igneous Province of the world and makes a unique setting for investigating models of basin subsidence and their interaction with mantle plumes. Our study consists of (1) an analysis of the Moho interaction phases in the receiver functions to obtain the thickness and bulk Vp/Vs ratio of the basin`s underlying crust and (2) a joint inversion with Rayleigh-wave dispersion velocities from an independent tomographic study to delineate the detailed S-wave velocity variation with depth. The results of our analysis reveal that Moho depths and bulk Vp/Vs ratios (including sediments) vary between 41 and 48 km and between 1.70 and 1.76, respectively, with the largest values roughly coinciding with the basin`s axis, and that S-wave velocities in the lower crust are generally below 3.8 km/s. Select sites within the basin, however, show lower crustal S-wave velocities slightly above 3.9 km/s suggestive of underplated mafic material. We show that these observations are consistent with a fragmented cratonic root under the Parana basin that defined a zone of weakness for the initial Paleozoic subsidence of the basin and which allowed localized mafic underplating of the crust along the suture zones by Cenozoic magmatism.

High-power diode laser in the disinfection in depth of the root canal dentin

Objective. The objective of this study was to evaluate the disinfection degree of dentine caused by the use of diode laser after biomechanical procedures. Study design. Thirty teeth were sectioned and roots were autoclaved and incubated for 4 weeks with a suspension of Enterococcus faecalis. The specimens were randomly divided into 3 groups (n = 10): G1, instrumented with rotary files, irrigated with 0.5% sodium hypochlorite and 17% EDTA-T, and then irradiated by 830-nm diode laser at 3 W; G2, the same procedures as G1 but without laser irradiation; and G3, irrigation with saline solution (control). Dentin samples of each third were collected with carbide burs and aliquots were sowed to count viable cells. Results. The disinfection degree achieved was 100% in G1 and 98.39% in G2, when compared to the control group (G3). Conclusion. Diode laser irradiation provided increased disinfection of the deep radicular dentin in the parameters and samples tested.

ROOT PROBLEM FOR CONVENIENT MAPS

In this paper we study when the minimal number of roots of the so-called convenient maps horn two-dimensional CW complexes into closed surfaces is zero We present several necessary and sufficient conditions for such a map to be root free Among these conditions we have the existence of specific fittings for the homomorphism induced by the map on the fundamental groups, existence of the so-called mutation of a specific homomorphism also induced by the map, and existence of particular solutions of specific systems of equations on free groups over specific subgroups

Photoproduction of J/psi and of high mass e(+)e(-) in ultra-peripheral Au plus Au collisions at root s(NN)=200 GeV

We present the first measurement of photoproduction of J/psi and of two-photon production of high-mass e(+)e(-) pairs in electromagnetic (or ultra-peripheral) nucleus-nucleus interactions, using Au + Au data at root s(NN) = 200 GeV. The events are tagged with forward neutrons emitted following Coulomb excitation of one or both Au* nuclei. The event sample consists of 28 events with m(e+e-) > 2 GeV/c(2) with zero like-sign background. The measured cross sections at midrapidity of d sigma/dy (J/psi + Xn, y = 0) = 76 +/- 33 (stat) +/- 11 (syst) pb and d(2)sigma /dm dy (e(+) e(-) + Xn, y = 0) = 86 +/- 23(stat) +/- 16(syst) mu b/ (GeV/c(2)) for m(e+e-) epsilon vertical bar 2.0, 2.8 vertical bar GeV/c(2) have been compared and found to be consistent with models for photoproduction of J/psi and QED based calculations of two-photon production of e(+)e(-) pairs. (C) 2009 Elsevier B.V. All rights reserved.

Dilepton mass spectra in p plus p collisions at root s=200 GeV

PHENIX has measured the electron-positron pair mass spectrum from 0 to 8 GeV/c(2) in p + p collisions at root s = 200 GeV. The contributions from light meson decays to e(+)e(-) pairs have been determined based on measurements of hadron production cross sections by PHENIX. Within the systematic uncertainty of similar to 20% they account for all e(+)e(-) pairs in the mass region below similar to 1 GeV/c(2). The e(+)e(-) pair yield remaining after subtracting these contributions is dominated by semileptonic decays of charmed hadrons correlated through flavor conservation. Using the spectral shape predicted by PYTHIA, we estimate the charm production cross section to be 544 +/- 39(stat) +/- 142(syst) +/- 200(model) pb. which is consistent with QCD calculations and measurements of single leptons by PHENIX. (C) 2008 Elsevier BV. All rights reserved.

Longitudinal scaling property of the charge balance function in Au plus Au collisions at root s(NN)=200 GeV

We present measurements of the charge balance function, from the charged particles, for diverse pseudorapidity and transverse momentum ranges in Au + Au collisions at root S(NN) = 200 GeV using the STAR detector at RHIC. We observe that the balance function is boost-invariant within the pseudorapidity coverage vertical bar-1.3, 1.3 vertical bar. The balance function properly scaled by the width of the observed pseudorapidity window does not depend on the position or size of the pseudorapidity window. This scaling property also holds for particles in different transverse momentum ranges. In addition, we find that the width of the balance function decreases monotonically with increasing transverse momentum for all centrality classes. (c) 2010 Elsevier B.V. All rights reserved.

Root uptake and reduction of hexavalent chromium by aquatic macrophytes as assessed by high-resolution X-ray emission

Aquatic macrophytes Salvinia auriculata, Pistia stratiotes and Eichhornia crassipes were chosen to investigate the Cr(VI) reduced by root-based biosorption in a chromium uptake experiment, using a high-resolution XRF technique. These plants were grown in hydroponics medium supplied with non-toxic Cr concentrations during a 27-day metal uptake experiment. The high-resolution Cr-K beta fluorescence spectra for dried root tissues and Cr reference material (100% Cr, Cr(2)O(3), and CrO(3)) were measured using an XRF spectrometer. For all species of aquatic plant treated with Cr(VI), the energy of the Cr-K beta(2,5) line was shifted around 8 eV below the same spectral line identified for the Cr(VI) reference, but it was also near to the line identified for the Cr(III) reference. Moreover, there was a lack of the strong Cr-K beta"" line assigned to the Cr(VI) reference material within the Cr(VI)-treated plant spectra, suggesting the reduction of Cr(VI) for other less toxic oxidation states of Cr. As all Cr-K beta spectra of root tissue species were compared, the peak energies and lineshape patterns of the Cr-K beta(2,5) line are coincident for the same aquatic plant species, when they were treated with Cr(III) and Cr(VI). Based on the experimental evidence, the Cr(VI) reduction process has happened during metal biosorption by these plants. (C) 2009 Elsevier Ltd. All rights reserved.

Inhibition Effect on the Allium cepa L. Root Growth When Using Hexavalent Chromium-Doped River Waters

The effect of Cr(6+) on Allium cepa root length was studied using both clean and polluted river waters. Seven series of Cr(6+)-doped polluted and non-polluted river waters were used to grow onions. Chromium concentration (Cr(6+)) of 4.2 mg L(-1)(EC(50) value), doped in clean river water caused a 50% reduction of root length, while in organically polluted samples similar root growth inhibition occurred at 12.0 mg Cr(6+) L(-1). The results suggested that there was a dislocation to higher values in toxic chromium concentration in polluted river water due to the eutrophization level of river water.

J/psi production in pp collisions at root s=200GeV in the STAR experiment

In this work we present the J/psi measurement in p+p collisions within the STAR collaboration Quarkonium program. This measurements aim to be the baseline measurement of a more comprehensive systematic study of quarkonium states production in order to understand their in medium modification. Here we report the total cross section and rho(T) distribution, and find them to be consistent with pQCD CEM predictions as well as to previous measurements at the same center-of-mass energy.