Evaluation of the conversion degree, microhardness, and surface roughness of composite resins used after their expiration date

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...

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Bibliographic Details
Published inGeneral dentistry Vol. 58; no. 6; p. e262
Main Authors Garcia, Lucas da Fonseca Roberti, Roselino, Lourenco de Moraes Rego, Pires-de-Souza, Fernanda de Carvalho Panzeri, Consani, Simonides
Format Journal Article
LanguageEnglish
Published United States 01.11.2010
Subjects
Carbon - chemistry
Chemical Phenomena
Composite Resins - chemistry
Dental Materials - chemistry
Drug Storage
Hardness
Humans
Materials Testing
Polymerization
Silicon Dioxide - chemistry
Spectroscopy, Fourier Transform Infrared
Surface Properties
Time Factors
Zirconium - chemistry
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Summary: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.
ISSN:0363-6771