RESUMO
AIM: This study compared the bond strength durability of a feldspathic veneering ceramic to glass-infiltrated reinforced ceramics in dry and aged conditions. METHODS: Disc shaped (thickness: 4 mm, diameter: 4 mm) of glass-infiltrated alumina (In-Ceram Alumina) and glass-infiltrated alumina reinforced by zirconia (In-Ceram Zirconia) core ceramic specimens (N=48, N=12 per groups) were constructed according to the manufacturers' recommendations. Veneering ceramic (VITA VM7) was fired onto the core ceramics using a mold. The core-veneering ceramic assemblies were randomly divided into two conditions and tested either immediately after specimen preparation (Dry) or following 30000 thermocycling (5-55 ºC±1; dwell time: 30 seconds). Shear bond strength test was performed in a universal testing machine (cross-head speed: 1 mm/min). Failure modes were analyzed using optical microscope (x20). The bond strength data (MPa) were analyzed using ANOVA (α=0.05). RESULTS: Thermocycling did not decrease the bond strength results for both In-Ceram Alumina (30.6±8.2 MPa; P=0.2053) and In-Ceram zirconia (32.6±9 MPa; P=0.3987) core ceramic-feldspathic veneering ceramic combinations when compared to non-aged conditions (28.1±6.4 MPa, 29.7±7.3 MPa, respectively). There were also no significant differences between adhesion of the veneering ceramic to either In-Ceram Alumina or In-Ceram Zirconia ceramics (P=0.3289). Failure types were predominantly a mixture of adhesive failure between the veneering and the core ceramic together with cohesive fracture of the veneering ceramic. CONCLUSION: Long-term thermocycling aging conditions did not impair the adhesion of the veneering ceramic to the glass-infiltrated alumina core ceramics tested.
Assuntos
Cerâmica , Porcelana Dentária , Facetas Dentárias , Temperatura Alta , Colagem Dentária , Falha de Equipamento , Vidro , Umidade , Técnicas In Vitro , Teste de Materiais , Distribuição Aleatória , Resistência ao Cisalhamento , Fatores de TempoRESUMO
Genital manifestations in schistosomiasis haematobium are common and are associated with considerable morbidity. Although Schistosoma mansoni may also cause genital disease, the frequency of this complication is not known. Cervical biopsies (N=401) and Pap smears (N=981) were therefore collected from women living in two S. mansoni-endemic areas (in the states of Alagoas and Ceará, in north-eastern Brazil). The women were screened for the presence of sexually transmitted diseases and for the presence, in their cervical smears and/or biopsies, of S. mansoni eggs. Attempts at schistosomiasis control, which began in both study areas in 1977, have led to generally low intensities of infection (<30 eggs/g faeces in 99% of infections) and community prevalences of infection that range between 1% and 52%. As no schistosome ova were detected in any of the biopsies or smears, it appears that the risk, among women, of genital manifestations of S. mansoni infection is small in areas where the parasite load in the population is low (as the result of interventions to control intestinal schistosomiasis).
Assuntos
Doenças Endêmicas , Esquistossomose mansoni/epidemiologia , Doenças do Colo do Útero/parasitologia , Adolescente , Adulto , Idoso , Animais , Biópsia/métodos , Brasil/epidemiologia , Colo do Útero/parasitologia , Colo do Útero/patologia , Colposcopia/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Teste de Papanicolaou , Vigilância da População , Prevalência , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/patologia , Doenças do Colo do Útero/epidemiologia , Doenças do Colo do Útero/patologia , Esfregaço VaginalRESUMO
In a recent epidemiological survey of more than 700 Brazilian medical students, we found new evidence on a previously reported pattern of the "lança perfume" inhalant drug use. With multiple logistic regression used to hold constant an array of suspected correlates, we found a moderately strong association between the use of marijuana and the use of lança (adjusted odds ratio, OR = 5.6; p < .01). We also found that lança is almost never used by students who have never consumed alcoholic beverages. This pattern of associations can be used to guide the planning of programs to reduce the occurrence of illicit use of pharmaceutical compounds by medical students in Brazil.
Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Anestésicos Inalatórios , Drogas Ilícitas , Estudantes de Medicina/estatística & dados numéricos , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Administração por Inalação , Adolescente , Adulto , Brasil/epidemiologia , Distribuição de Qui-Quadrado , Intervalos de Confiança , Feminino , Inquéritos Epidemiológicos , Humanos , Funções Verossimilhança , Modelos Logísticos , Masculino , Fumar Maconha/epidemiologia , Razão de Chances , Fatores de RiscoRESUMO
Non-medical drug use among medical students is a major concern among researchers and policy makers in several countries, not only because of the personal harmful consequences that may arise from this behavior, but also for the social consequences. This article aims to evaluate national and international data available on non-medical drug-use among medical students and risk factors associated with these problems, as well as social and institutional implications. Prevalence rates, in Brazilian and international samples, of alcohol and drug use, abuse and dependence, reasons for onset, methodological issues, and the role of medical education are presented, compared and discussed. The authors suggest some issues that should be a addressed in order to deal with this complex situation.