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Evaluation of the conversion degree, microhardness, and surface roughness of composite resins used after their
Lucas da Fonseca Roberti Garcia1, Lourenco de Moraes Rego Roselino, Fernanda de Carvalho Panzeri Pires-de-Souza
1Piracicaba School of Dentistry, State University of Campinas, Piracicaba, Sao Paolo, Brazil.
Abstract:
This study evaluated the conversion degree associated with microhardness and surface roughness of four composite resins used 180 days before and after their expiration dates. Ten specimens of each composite were made in a Teflon matrix (2 mm x 7 mm), separated into two groups (n = 10), and submitted to Vickers microhardness (a 10 N load for 15 seconds), R(a)roughness (cut-off 0.25 mm), and conversion degree evaluation. The data submitted to the two-way ANOVA (p < 0.05) showed a reduction in microhardness for the composites used after their expiration dates. It was concluded that the expired composites had altered properties.
