RESUMO
OBJECTIVE: To evaluate the degree of conversion (DC), flexural strength (FS) and Knoop microhardness (KHN) of direct and indirect composite resins polymerized with different curing systems. MATERIALS AND METHODS: Specimens of direct (Z250, 3M/Espe) and indirect (Sinfony, 3M/Espe) restorative materials were made and polymerized using two light curing units: XL2500 (3M/Espe) and Visio system (3M/Espe). Absorption spectra of both composites were obtained on a FTIR spectrometer in order to calculate the DC. FS was evaluated in a universal testing machine and surface microhardness was performed in a microhardness tester (50gf/15s). DC, FS and KHN data were submitted to two-way ANOVA and Tukey's test (α = 0.05). RESULTS: Z250 showed higher DC, FS and KHN compared with Sinfony when the polymerization was carried out with XL2500 (p < 0.05). However, there is no statistical difference in DC between the materials when Visio was used (p > 0.05). Visio showed higher DC and KHN for Z250 and Sinfony than the values obtained using XL2500 light curing (p < 0.05). For FS, no significant difference between curing units was found (p > 0.05). CONCLUSION: Even though the Visio system could increase DC and KHN for some direct and indirect composites, compared with the conventional halogen curing unit, a high number of monomers did not undergo conversion during the polymerization.
Assuntos
Resinas Compostas , Lâmpadas de Polimerização Dentária , Teste de Materiais , Análise de VariânciaRESUMO
El Instituto Nacional de Estudio e Investigación del Ministerio de Educación afirmó tener 169 facultades de odontología en el 2006. En la facultad de odontología de Araçatuba, UNESP, la disciplina de Bioestadística está incluida en el curso con 90 horas de crédito por un año. La interrelación con otros profesores fue desarrollada usando la base de datos de campos odontológicos diferentes. El objetivo de esta pesquisa es examinar la enseñanza de bioestadística en todas las facultades de odontología de Brasil. La metodología aplicada fue enviar el cuestionario a todos los coordinadores de los cursos. Dando como resultado 80 cuestionarios respondidos, 48 indicaron la inclusión de bioestadística en sus programas curriculares. Solamente en 3 escuelas la Bioestadística es enseñada durante todo el año de "61 a 90" horas. La enseñanza de Bioestadística debe ser incentivada en todas las facultades de odontología en Brasil, de modo que, pueda despertar el interés de estas, con respecto a la inclusión de la disciplina de bioestadística en su programa curricular.
The National Institute of Study and Research of the Ministry of Education in Brazil states that there are 169 Schools of Dentistry in 2006. At the School of Dentistry of Araçatuba, UNESP, Brazil, this Biostatistics discipline is included in the course with 90 credit hours a year. An interrelationship with other professors has been developed for some years using database of different dental fields. The aim of this research is to get acquainted with the teaching of Biostatics at schools of dentistry in Brazil. The methodology applied was to send the questionnaire to all the coordinators of the courses. As for the result of 80 questionnaires answered, 48 stated the inclusion of Biostatistics in their program studies. Only in 3 schools Biostatistics is taught all over the year in "61 to 90" hours. The conclusion is that the teaching of Biostatistics must be incentivated in all schools of dentistry in Brazil.
