Evaluation Of The Radiopacity Of Esthetic Root Canal Posts.

The radiopacity of esthetic root canal posts may impair the assessment of their fit to the root canal when using radiographic images. This study determined in vitro the radiographic density of esthetic root canal posts using digital images. Thirty-six roots of human maxillary canines were assigned to six groups (N=6 per group): Reforpost (RP); Aestheti-Plus (AP); Reforpost MIX (RPM); D.T. Light Post (LP); Reforpost Radiopaque (RPR); and White Post DC (WP). Standardized digital images of the posts were obtained in different conditions: outside the root canal, inside the canal before and after cementation using luting material, and with a tissue simulator. Analysis of variance was used to compare the radiopacity mean values among the posts outside the root canal and among the posts under the other conditions, and the t unpaired test to compare the radiopacity between the posts and the dentin, and between the posts and the root canal space. There was no statistically significant difference in radiopacity between RP and RPM, and LP and WP. AP posts showed radiopacity values significantly lower than those for dentin. No statistically significant difference was found between posts (RP and AP) and the root canal space. A statistically significant difference was observed between the luted and non-luted posts; additionally, luted posts with and without tissue simulator showed no significant differences. Most of the cement-luted posts analyzed in this study were distinguishable from the density of adjacent dentin surfaces, allowing radiographic confirmation of the fit of the post in the canal. The success of using esthetic root canal posts depends mainly on the fit of the post within the canal.[1] The radiopacity of a post allows for radiographic imaging to be used to determine the fit, an important factor in a clinical perspective.

Neuromuscular Activity Of Bothrops Fonsecai Snake Venom In Vertebrate Preparations.

The neuromuscular activity of venom from Bothrops fonsecai, a lancehead endemic to southeastern Brazil, was investigated. Chick biventer cervicis (CBC) and mouse phrenic nerve-diaphragm (PND) preparations were used for myographic recordings and mouse diaphragm muscle was used for membrane resting potential (RP) and miniature end-plate potential (MEPP) recordings. Creatine kinase release and muscle damage were also assessed. In CBC, venom (40, 80 and 160μg/ml) produced concentration- and time-dependent neuromuscular blockade (50% blockade in 85±9 min and 73±8 min with 80 and 160μg/ml, respectively) and attenuated the contractures to 110μM ACh (78-100% inhibition) and 40mM KCl (45-90% inhibition). The venom-induced decrease in twitch-tension in curarized, directly-stimulated preparations was similar to that in indirectly stimulated preparations. Venom (100 and 200μg/ml) also caused blockade in PND preparations (50% blockade in 94±13 min and 49±8 min with 100 and 200μg/ml, respectively) but did not alter the RP or MEPP amplitude. In CBC, venom caused creatine kinase release and myonecrosis. The venom-induced decrease in twitch-tension and in the contractures to ACh and K(+) were abolished by preincubating venom with commercial antivenom. These findings indicate that Bothrops fonsecai venom interferes with neuromuscular transmission essentially through postsynaptic muscle damage that affects responses to ACh and KCl. These actions are effectively prevented by commercial antivenom.

Otorhinolaryngological Findings In A Group Of Patients With Rheumatic Diseases.

Otorhinolaryngological manifestations of rheumatologic diseases represent a great challenge not only to the generalistphysician but also to the ENT doctor andrheumatologist. They often represent early manifestations of an autoimmune disorder which requires prompt and aggressive immunosuppressive treatment. Auditory, nasal, laryngeal and eye symptoms can be the first manifestation of rheumatic diseases and their proper assessment helps the doctor to identify signs of disease activity. The objective of this study is to identify the ENT manifestations in patients with rheumatic diseases in a high complexity hospital, regarding facilitating an early diagnosis and treatment. We performed clinical and complete otorhinolaryngological evaluations in patients selected from the outpatient rheumatology in a standardized manner by the use of a standardized form filling during the secondhalf of 2010. In the study group, systemic lupus erythematosus (SLE) patients had predominantly laryngeal manifestations, while patients with Sjögren's syndrome showed a higher prevalence of otologic manifestations. Changes in audiometric tests were found in 53% of Wegener's granulomatosis (WG) patients, 80% of relapsing polychondritis (RP), 33% of systemic lupus erythematosus (SLE) and 50% of Churg-Strauss syndrome (SCS). Regarding nasal alterations, these were found so prevalent in all conditions, especially Churg-Strauss syndrome. This study demonstrated that most patients treated in our hospital has the ENT signs and symptoms commonly associated in previous studies on rheumatic diseases, but further studies with a larger number of patients must be made to establish such relations.

Corrosion Kinetics And Topography Analysis Of Ti-6al-4v Alloy Subjected To Different Mouthwash Solutions.

This study evaluated the corrosion kinetics and surface topography of Ti-6Al-4V alloy exposed to mouthwash solutions (0.12% chlorhexidine digluconate, 0.053% cetylpyridinium chloride and 3% hydrogen peroxide) compared to artificial saliva (pH6.5) (control). Twenty Ti-6Al-4V alloy disks were used and divided into 4 groups (n=5). For the electrochemical assay, standard tests as open circuit potential and electrochemical impedance spectroscopy (EIS) were applied at baseline, 7 and 14days after immersion in the solutions. Scanning electron microscopy, atomic force microscopy and profilometry (average roughness - Ra) were used for surface characterization. Total weight loss of disks was calculated. Data were analyzed by ANOVA and Bonferroni's test (α=0.05). Hydrogen peroxide generated the lowest polarization resistance (Rp) values for all periods (P<0.05). For the capacitance (Cdl), similar results were observed among groups at baseline (P=0.098). For the 7 and 14-day periods, hydrogen peroxide promoted the highest Cdl values (P<0.0001). Hydrogen peroxide promoted expressive superficial changes and greater Ra values than the others (P<0.0001). It could be concluded that solutions containing cetylpyridinium chloride and chlorhexidine digluconate might be the mouthwashes of choice during the post-operatory period of dental implants. However, hydrogen peroxide is counter-indicated in these situations. Further studies evaluating the dynamics of these solutions (tribocorrosion) and immersing the disks in daily cycles (two or three times a day) to mimic a clinical situation closest to the application of mouthwashes in the oral cavity are warranted to prove our results.

Bp-13 Pla2: Purification And Neuromuscular Activity Of A New Asp49 Toxin Isolated From Bothrops Pauloensis Snake Venom.

A new PLA2 (Bp-13) was purified from Bothrops pauloensis snake venom after a single chromatographic step of RP-HPLC on μ-Bondapak C-18. Amino acid analysis showed a high content of hydrophobic and basic amino acids and 14 half-cysteine residues. The N-terminal sequence showed a high degree of homology with basic Asp49 PLA2 myotoxins from other Bothrops venoms. Bp-13 showed allosteric enzymatic behavior and maximal activity at pH 8.1, 36°-45°C. Full Bp-13 PLA2 activity required Ca(2+); its PLA2 activity was inhibited by Mg(2+), Mn(2+), Sr(2+), and Cd(2+) in the presence and absence of 1 mM Ca(2+). In the mouse phrenic nerve-diaphragm (PND) preparation, the time for 50% paralysis was concentration-dependent (P < 0.05). Both the replacement of Ca(2+) by Sr(2+) and temperature lowering (24°C) inhibited the Bp-13 PLA2-induced twitch-tension blockade. Bp-13 PLA2 inhibited the contractile response to direct electrical stimulation in curarized mouse PND preparation corroborating its contracture effect. In biventer cervicis preparations, Bp-13 induced irreversible twitch-tension blockade and the KCl evoked contracture was partially, but significantly, inhibited (P > 0.05). The main effect of this new Asp49 PLA2 of Bothrops pauloensis venom is on muscle fiber sarcolemma, with avian preparation being less responsive than rodent preparation. The study enhances biochemical and pharmacological characterization of B. pauloensis venom.

Saúde dos adolescentes: um estudo de base populacional em Campinas, São Paulo, Brasil

We estimated the prevalence of chronic diseases and other health problems reported by adolescents in relation to social and demographic variables and nutritional status. This cross-sectional population-based survey analyzed data from the Health Survey in Campinas, São Paulo State, Brazil, 2008. We used descriptive statistics and associations between variables with the chisquare test. Prevalence of chronic diseases among adolescents was 19.17%, with asthma showing the highest prevalence (7.59%), followed by heart disease (1.96%), hypertension (1.07%), and diabetes 0.21%. Prevalence rates were 61.53% for health problems, 40.39% for allergy, and 24.83% for frequent headache or migraine. After multivariate analysis using Poisson regression, the factors associated with chronic disease were age 15 to 19 years (PR = 1.38), not attending school (PR = 1.46), having children (PR = 1.84), and obesity (PR = 1.54). Female gender (PR = 1.12) was statistically associated with health problems. The study illustrates that adolescence is a life stage in which chronic disease and health problems can occur.