RESUMEN
OBJECTIVES: The aim of this study was to examine the effect of intermediate resin (IMR) of different monomer compositions and viscosities on the shear bond strength between polymer substrate and light-curing composite. METHODS: The substrate used in the study was an autopolymerizing polymethyl methacrylate (PMMA) based polymer. The substrate was treated with the IMR for 3 min before application of light polymerizable particulate filler composite resin. The monomers of the IMR were either bisphenol-A-glycidyl dimethacrylate (BisGMA) and triethyleneglycol dimethacrylate (TEGDMA) or BisGMA and methyl methacrylate (MMA). The shear bond strength of the IMR treated substrate to the particulate filler composite was evaluated after storing the specimens dry and after thermocycling the specimens in water. Light microscope examination was accomplished to determine the swelled layer of the substrate. RESULTS: Significant differences were found between the shear bond strength values of the IMRs (p < 0.001). The bond strengths were generally higher in the BisGMA-MMA groups than in the BisGMA-TEGDMA groups. Two-way ANOVA revealed significant effects of type of IMR (p < 0.001) and thermocycling (p = 0.017) on the shear bond strength. No interaction was found between these variables (p > 0.05). CONCLUSIONS: The results suggest that the monomer composition and ratio of the IMRs used in the study influence the shear bond strength of the polymer substrate to the new resin.
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Resinas Sintéticas , Ensayo de MaterialesRESUMEN
OBJECTIVE: The purpose of this study was to analyze the shear bond strength of a new composite resin to polymer-based composite substrates using various surface roughnesses and two kinds of polymer matrices. MATERIALS AND METHODS: Particulate filler composite resin with cross-linked polymer matrix and fiber-reinforced composite with semi-interpenetrating polymer matrix were used as bonding substrates after being ground to different roughnesses. Substrates were aged in water for one week before bonding to new resin composites. Twelve specimens in the substrate groups were ground with grinding papers of four grits; 320, 800, 1200 and 2400. RESULTS: Corresponding values of surface roughness (Ra) varied from 0.09 to 0.40 for the particulate filler composite resin and 0.07 to 0.96 for the fiber-reinforced composite resin. Characteristic shear bond strength between the new resin and particulate filler composite resin was highest (27.8 MPa) with the roughest surface (Weibull modulus: 2.085). Fiber-reinforced composite showed the highest bond strength (20.8 MPa) with the smoothest surface (Weibull modulus: 4.713). CONCLUSIONS: We concluded that surface roughness did not increase the bonding of new resin to the substrate of IPN based fiber-reinforced composite, whereas the roughness contributed to bonding the new resin to the particulate filler composite resin with a cross-linked polymer matrix.
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OBJECTIVES: To study the safety and efficacy of vitamin D3 as an add on therapy to interferon ß-1b (IFNB) in patients with multiple sclerosis (MS). METHODS: 1 year, double blind, placebo controlled, randomised study in 66 MS patients. The primary outcomes were T2 burden of disease (BOD) on MRI scans, proportion of patients with serum levels of 25-hydroxyvitamin D (25(OH)D) ≥85 nmol/l or intact parathyroid hormone (PTH) ≤20 ng/l, and number of adverse events. Secondary outcomes were number of MRI enhancing T1 lesions and new T2 lesions, annual relapse rate, changes in the Expanded Disability Status Scale score, timed 25 foot walk test and timed 10 foot tandem walk tests. RESULTS: Median change in BOD was 287 mm(3) in the placebo group and 83 mm(3) in the vitamin D group (p=0.105). Serum levels of 25(OH)D increased from a mean of 54 (range 19-82) nmol/l to 110 (range 67-163) nmol/l in the vitamin D group. 84% of patients reached a serum 25(OH)D level >85 nmol/l in the vitamin D group and 3% in the placebo group (p<0.0001). Patients in the vitamin D group showed fewer new T2 lesions (p=0.286) and a significantly lower number of T1 enhancing lesions (p=0.004), as well as a tendency to reduced disability accumulation (p=0.071) and to improved timed tandem walk (p=0.076). There were no significant differences in adverse events or in the annual relapse rate. CONCLUSION: Vitamin D3 add on treatment to IFNB reduces MRI disease activity in MS. TRIAL REGISTRATION NUMBER: EudraCT number 2007-001958-99 and ClinicalTrialsGov number NCT01339676.
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Adyuvantes Inmunológicos/uso terapéutico , Colecalciferol/uso terapéutico , Interferón beta/uso terapéutico , Esclerosis Múltiple/tratamiento farmacológico , Vitaminas/uso terapéutico , Adyuvantes Inmunológicos/administración & dosificación , Adolescente , Adulto , Encéfalo/patología , Colecalciferol/administración & dosificación , Colecalciferol/efectos adversos , Colecalciferol/farmacocinética , Método Doble Ciego , Quimioterapia Combinada/efectos adversos , Femenino , Humanos , Inyecciones Subcutáneas , Interferon beta-1b , Interferón beta/administración & dosificación , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/sangre , Esclerosis Múltiple/patología , Neuroimagen/métodos , Hormona Paratiroidea/sangre , Recurrencia , Índice de Severidad de la Enfermedad , Vitamina D/análogos & derivados , Vitamina D/sangre , Vitaminas/administración & dosificación , Vitaminas/efectos adversos , Vitaminas/farmacocinética , CaminataRESUMEN
Studies on carotid artery atherosclerosis have been performed in order to understand the high risk for cardiovascular disease in chronic renal failure (CRF). The purpose of this study was to evaluate the extent and nature of carotid artery atherosclerosis in patients with CRF. Of the 135 patients with CRF (52 +/- 11 years), 58 had moderate to severe predialysis CRF (PR), 36 were on dialysis treatment (DI), and 41 were renal transplant recipients (TR). In addition, 58 control subjects (CO) were examined. Common carotid artery intima-media thickness (IMT), plaque prevalence, plaque score, and stiffness index beta were determined. Furthermore, plaque calcification and internal carotid artery stenoses were classified. Plaque prevalence (PR 64%, DI 61%, TR 51%, CO 28%; P < 0.001) and plaque score (PR 3.3 +/- 4.3, DI 3.0 +/- 3.4, TR 2.5 +/- 3.2, CO 0.8 +/- 1.7 mm; P < 0.001) were significantly greater in the CRF patient groups compared to the controls, whereas no difference in IMT was noted between the study groups. The prevalences of plaque calcification and internal carotid artery stenoses were higher among the CRF patient groups. In addition, the stiffness index beta was higher in the CRF patient groups. The present study shows that the characteristic alterations of the carotid arteries in CRF include increased plaque burden, calcification and increased arterial stiffness.
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Enfermedades de las Arterias Carótidas/diagnóstico , Enfermedades de las Arterias Carótidas/epidemiología , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/epidemiología , Túnica Íntima/patología , Adulto , Distribución por Edad , Anciano , Análisis de Varianza , Análisis Químico de la Sangre , Enfermedades de las Arterias Carótidas/terapia , Estudios de Casos y Controles , Estudios de Cohortes , Comorbilidad , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Fallo Renal Crónico/terapia , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Probabilidad , Valores de Referencia , Medición de Riesgo , Índice de Severidad de la Enfermedad , Distribución por Sexo , Estadísticas no ParamétricasRESUMEN
A prospective study was carried out to evaluate the effect of teleradiology on the diagnosis, treatment and prognosis of patients in primary care. A university hospital was sent 685 plain film examinations via an ISDN connection from a primary care centre, for a radiological report. The study was conducted in two phases: during phase 1 (446 cases) general practitioners (GPs) selected the examinations, and during phase 2 (239 cases) all consecutive examinations were transmitted. In phase 1, 40% of the examinations were of the chest and 24% were of the spine; the remaining 36% were mainly bone and sinus examinations. In phase 2, 28% of the examinations were of the chest and 19% were of the spine. The sensitivity and specificity of the GPs' interpretations (compared with the radiologists') were 0.85 and 0.62 respectively in the first phase, and 0.90 and 0.86 in the second. In at least one-third of all cases, teleradiology helped with the diagnosis, although completely new diagnoses were less common. An effect on treatment was noted in 15% of cases and on prognosis in 5%. However, an appropriate consultation level is required for these positive effects. Adequate accuracy and patient safety cannot be achieved if the examinations sent for radiological reporting are preselected by a GP.