Influence of fluoride-releasing restorative material on root dentine secondary caries in situ

The usefulness of fluoride-releasing restorations in secondary caries prevention may be questioned because of the presence of other common sources of fluoride and because of ageing of the restorations. This study tested the hypothesis that glass-ionomer cement restorations, either aged or unaged, do not prevent secondary root caries, when fluoride dentifrice is frequently used. Sixteen volunteers wore palatal appliances in two phases of 14 days, according to a 2 x 2 crossover design. In each phase the appliance was loaded with bovine root dentine slabs restored with either glass-ionomer or resin composite, either aged or unaged. Specimens were exposed to cariogenic challenge 4 times/day and to fluoridated dentifrice 3 times/day. The fluoride content in the biofilm (FB) formed on slabs and the mineral loss (Delta Z) around the restorations were analysed. No differences were found between restorative materials regarding the FB and the Delta Z, for either aged (p = 0.792 and p = 0.645, respectively) or unaged (p = 1.00 and p = 0.278, respectively) groups. Under the cariogenic and fluoride dentifrice exposure conditions of this study, the glass-ionomer restoration, either aged or unaged, did not provide additional protection against secondary root caries. Copyright (c) 2006 S. Karger AG, Basel.

Online distance mathematics education in Brazil: research, practice and policy

In this article, we address online distance mathematics education research and practice in Brazil, which are relative newcomers to the educational scene. We present the national context of education in Brazil, highlighting the organization of the educational system, and also a summary of national legislation on distance education and an overview of digital inclusion in the country. We outline the potential and relevance of distance education for the Brazilian educational system and show how it could intervene in the system. With respect to research and practice in online mathematics education, we present support for research, examples of studies and highlight different aspects being addressed, including its essential components. In addition, we discuss the synergy between distance education and teacher education, and mathematics distance education and modeling, as well as other initiatives in the national scenario.

Higher education in evening courses in Brazil: history, growth and public policies at the beginning of the XXI Century

There are three distinct and complementary objectives in this article in order to clarify the higher education outline in Brazil, specifically evening courses (classes are held on weekdays, generally from 7:00 pm to 10:30 pm) and thesecurrent sector policies. The first objective is to present a short historical overview on the establishment of evening courses in Brazil, including those in the higher education level, occurred on the middle of last century. The second objective is to demonstrate the growth of evening higher education in Brazil, considering that in 1998, of the 2.1 million college enrollments, 55.3% were enrolled in evening courses; in 2010, twelve years later, of the 5.4 million students enrolled, there were 63.5% enrolled in evening courses. This expansion is due to the growing need of many students who must work while attending college, to defray costs of the study as well as personal and family costs. The reality of the working student is hostile considering external factors, such as transport problems, public security and lack of legislation for flexible working hours. The third objective is to discuss current public policies to expand eveningopenings in public institutions which represent nowadays only 16.1% of the 3.4 million enrollments for evening classes, including federal (6.8%), state (7.0%) and municipal (2.3%) institutions. In the third objective it is included the discussion of programs for scholarships and tuition loans. The methodology applied was to rescue historical information on the establishment and the expansion of evening courses in Brazil, analyzing the current general Brazilian policies and the specific ones from the State of São Paulo. The research results pointed to the importance of federal programs for scholarships and tuition loans for students from private institutions such as the 1,382,484 scholarships since 2004 (PROUNI Program) and the 847,000 tuition loans since 1999 (FIES Program). Important steps have been made by the Brazilian government. Considering that there are 3,987,424 enrollments in private institutions, the effectiveness of the programs for scholarships and tuition loans is still insufficient to meet the universal benefits for the student’s needs. Evening courses became the real instrument of social inclusion for many Brazilian youths and must be expanded quantitatively and qualitatively, with aggressive public policies, including also, scholarships and tuition loans.