Effect of light sources on nanohardness, elastic modulus and water sorption of a composite resin

• Autor(a) principal: Juchem,Cristiane de O
• Data de Publicação: 2011
• Outros Autores: Leitune,Vicente C. B, Collares,Fabrício M, Samuel,Susana M. W
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Polímeros (São Carlos. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-14282011000200006
• topic: Composite resin; polymerization; light-curing unit; nanohardness; elastic modulus

The aim of this study was to evaluate the effect of a light source on nanohardness, elastic modulus, water sorption and solubility of a composite resin. Four curing units were used, three of which had an LED and another had a halogen source. The resin composite Z250 (3M ESPE) was used for all tests. For water sorption and solubility, five resin disks were made (15 mm in diameter and 1 mm thick), and these were polymerized for 20 seconds at nine different points (1 in the center and 8 around). For nanohardness and elastic modulus evaluation, 20 cylinders (5 for each group) were made with a bipartite steel matrix (6.0 mm diameter and 4.0 mm thick). The results of this study showed that the group polymerized with the Radii light-curing unit presented less water sorption than other curing units (p < 0.05). No statistical difference between units was found in nanohardness in 1mm-thick specimens. However, decreased nanohardness was shown at higher resin composite depth (p < 0.05). A Pearson correlation showed a strong positive relationship between nanohardness and elastic modulus for all groups and depths. The light source affects the water sorption, nanohardness and elastic modulus of composite resins.