Kinetic parameters and monomeric conversion of different dental composites using standard and soft-start photoactivation modes

This paper evaluates the photopolymerization kinetics and degree of conversion of different commercial dental composites when photoactivated by a LED curing unit using two different modes (standard and soft-start mode). The investigation was performed on with RelyX ARC (dual-cured), Filtek Z-350 (Nanocomposite), Filtek Z-250 (Hybrid), and Filtek Z-350flow (Flowable) resin composites. The analysis used was attenuated total reflection with a Fourier transform infrared (ATR-FTIR). The RelyX ARC resin demonstrated the highest degree of conversion with both LED photoactivation modes. For this resin a 28% decrease in maximum rate was observed and the time to reach its highest rate was almost 2.3 times higher than when the soft-start photoactivation light curing was used. Z-350flow resin recorder a higher maximum rate using the soft-start mode rather than the standard mode. In contrast, the Z-250 showed a higher value using the standard mode. Although Z-250 and Z-350 showed a higher total degree of conversion effectiveness using the soft-start mode, RelyX and Z-350flow achieved a higher value using the standard mode.

Challenges for nursing education in Angola: the perception of nurse leaders affiliated with professional education institutions

Background: Angola is one of the African countries with the highest morbidity and mortality rates and a devastating lack of human resources for health, including nursing. The World Health Organization stimulates and takes technical cooperation initiatives for human resource education and training in health and education, with a view to the development of countries in the region. The aim in this study was to identify how nurses affiliated with nursing education institutions perceive the challenges nursing education is facing in Angola. Methods: After consulting the National Directory of Human Resources in Angola, the nurse leaders affiliated with professional nursing education institutions in Angola were invited to participate in the study by email. Data were collected in February 2009 through the focus group technique. The group of participants was focused on the central question: what are the challenges faced for nursing education in your country? To register and understand the information, besides the use of a recorder, the reporters elaborated an interpretative report. Data were coded using content analysis. Results: Fourteen nurses participated in the meeting, most of whom were affiliated with technical nursing education institutions. It was verified that the nurse leaders at technical and higher nursing education institutions in Angola face many challenges, mainly related to the lack of infrastructure, absence of trained human resources, bureaucratic problems to regularize the schools and lack of material resources. On the opposite, the solutions they present are predominantly centered on the valuation of nursing professionals, which implies cultural and attitude changes. Conclusions: Public health education policies need to be established in Angola, including action guidelines that permit effective nursing activities. Professional education institutions need further regularizations and nurses need to be acknowledged as key elements for the qualitative enhancement of health services in the country.