Search results for "Molar"

Solution Properties of Poly-Electrolytes. XI. Adsorption Effects in Aqueous Size-Exclusion Chromatog-Raphy of Polyanions

1994

Abstract Elution profiles of a series of polymer standards such as sodium poly(styrene sulphonate), poly(acrylic acid) and poly(L-glutamic acid) have been obtained from size-exclusion chromatography experiments using separately two types of hydrophilic supports. A variety of mobile phase compositions have been performed to enhance adsorption effects in order to study how this phenomenon can affect to the chromatographic separation mechanism of polyanions. Distribution coefficient values, in general greater than unity, have served to quantify the adsorption effect, as well as to analyze their dependence on eluent ionic strength, on the ionic groups of the support and on the chemical nature a…

Ameloblastic fibroma: a rare case appearing as a mixed radiographic image

2014

Ameloblastic fibroma (AF) is a benign tumor of mixed odontogenic origin, which affects predominantly young individuals. AF appearing as a mixed radiographic image is very rare. This report describes a case of AF in a 12-year-old male identified during a routine radiographic exam for orthodontic treatment planning. The panoramic radiography revealed a well-defined multilocular mixed image located in the mandible between the roots of the left mandibular second premolar and first molar. The lesion was excised under local anesthesia. Histopathological analysis revealed islands of epithelial cells and columnar peripheral cells showing a nucleus in inverted polarization, interspersed with spindle…

Acanthocyturia—A characteristic marker for glomerular bleeding

1991

Acanthocyturia—A characteristic marker for glomerular bleeding. Erythrocyte morphology by phase contrast microscopic examination (PCM) of the urine is widely employed in distinguishing glomerular from nonglomerular bleeding. The proposed percentages of dysmorphic red cells are significant for glomerular bleeding in the range of 10 to 80% in the literature, because there is no clear cut definition of “dysmor-phism.” In the present study midstream urine samples of 351 patients with hematuria (> 8 erythrocytes/μl) and of 33 healthy controls were examined. The various dysmorphic red cells were analyzed by PCM according to a detailed hematological classification. Most of the dysmorphic red cells…

Cirugía de rescate (reubicación quirúrgica) en segundos molares inferiores impactados

2005

La impactación de los segundos molares inferiores es una complicación de la erupción dentaria muy infrecuente, dado que su incidencia se cifra de un 0,03 a un 0,21 %. Se ha detectado en mayor frecuencia de forma unilateral que bilateral y es más usual en mandíbula que en maxilar. Presenta una ligera predicción por el sexo masculino, y la inclinación mesial es la más habitual. Se han publicado una amplia variedad de aproximaciones terapéuticas, fundamentalmente apelando a técnicas quirúrgicas únicas o ayudadas de técnicas ortodóncicas, con el objeto de llevar al diente a su correcta posición, y que se engloban bajo el concepto de cirugía de rescate. En los casos resueltos con una reubicación…

A case series associated with different kinds of endo-perio lesions

2014

Pulpal and periodontal problems are responsible for more than half of the tooth mortality. There are some articles published in the literature about this issue. Many of them are quite old. There has been also lack of knowledge about the effect of endodontic treatment on the periodontal tissue healing and suitable treatment interval between endodontic and periodontal treatments. In this case report, different kinds of endo-perio lesion were treated with sequential endodontic and periodontal treatment. The follow-up radiographs showed complete healing of the hard and soft tissue lesions. The tooth with endo-perio lesions should be evaluated thoroughly in terms of any cracks and fracture, espe…

Experimental models of orthodontic tooth movement and their effects on periodontal tissues remodelling.

2021

Made available in DSpace on 2022-04-29T08:31:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Objectives: The present study aimed to compare two different models of orthodontic tooth movement (OTM) in rats by evaluating tooth movement efficiency and periodontal tissues remodelling. Design: Fifteen animals were randomly distributed into 3 groups: control group (untreated); ligature appliance (LA) as experimental OTM using a closed coil spring fixed around maxillary first molar by steel ligature; occlusal appliance (OA) as experimental OTM using a closed coil spring attached on the occlusal surface of the maxillary f…

The Electrostatic Expansion of Linear Polyelectrolytes:  Effects of Gegenions, Co-ions, and Hydrophobicity

1997

The molar mass and ionic strength dependence of the dimensions of hydrophobically modified poly(vinylpyridinium) cations are demonstrated to be almost perfectly described by a theoretical expression derived on the basis of only excluded volume considerations. Generally, the effective charge density of the polyions decreases significantly with increasing hydrophobicity and with increasing polarizability of the gegenions. Unexpectedly, the intrinsic excluded volume effect which becomes dominating at high ionic strength not only depends on the hydrophobicity of the polyion but also significantly increases with decreasing polarizability of the gegenions (i.e., if the iodide gegenions are replac…

1978

Theoretical relations for the dependence of the z-average radius of gyration Rz as a function of the mass average molar mass Mw are derived for expanded coils, persistence coils with persistence of direction, persistence coils with persistence of direction and curvature, and for needles, all exhibiting a Schulz-distribution of their molar masses. These relations are applied to experimental data from light scattering of polystyrene in toluene and DNA-Na in aqueous NaCl-solution of 200 mol NaCl per m3 at room temperature. In the case of DNA it becomes evident that the double helix shows no important persistence of curvature and that the experimental data can be described adequately by a persi…

Oral metamizol (1 g and 2 g) versus ibuprofen and placebo in the treatment of lower third molar surgery pain: randomised double-blind multi-centre st…

1998

Objective: To assess the efficacy of metamizol 1 g and 2 g in the relief of pain after surgical extraction of the lower third molar, and to compare the therapeutic effect with that of ibuprofen 600 mg or placebo.

Influence of molecular weight and polydispersity on phase behaviour of polyesters with laterally fixed or cross-shaped mesogens

1991

Abstract To supplement previous studies of polyesters with laterally attached and cross-shaped mesogens the influence of molecular weight and molecular weight distribution on the phase behaviour has been investigated. For that purpose two polyesters have been fractionated by preparative gel permeation chromatography under high pressure and observed by polarizing microscopy and DSC measurements. A monotropic nematic polyester with laterally attached mesogens shows changing phase transitions up to a molecular weight of 10 000 (Mw); at higher molecular weight only the clearing transition is still slightly influenced. The molecular weight distribution at an average molecular weight of 15 000 (M…