Flexural strength and hardness of direct and indirect composites
Braz. oral res
;
23(1): 5-10, 2009. tab
Artigo
em Inglês
| LILACS
| ID: lil-514635
ABSTRACT
The objective of this study was to evaluate the flexural strength (óf) and hardness (H) of direct and indirect composites, testing the hypotheses that direct resin composites produce higher óf and H values than indirect composites and that these properties are positively related. Ten bar-shaped specimens (25 mm x 2 mm x 2 mm) were fabricated for each direct [D250 - Filtek Z250 (3M-Espe) and D350 - Filtek Z350 (3M-Espe)] and indirect [ISin - Sinfony (3M-Espe) and IVM - VitaVM LC (Vita Zahnfabrik)] materials, according to the manufacturer's instructions and ISO4049 specifications. The óf was tested in three-point bending using a universal testing machine (EMIC DL 2000) at a crosshead speed of 0.5 mm/min (ISO4049). Knoop hardness (H) was measured on the specimens' fragments resultant from the óf test and calculated as H = 14.2P/l², where P is the applied load (0.1 kg; dwell time = 15 s) and l is the longest diagonal of the diamond shaped indent (ASTM E384). The data were statistically analyzed using Anova and Tukey tests (á = 0.05). The mean óf and standard deviation values (MPa) and statistical grouping were D250 - 135.4 ± 17.6a; D350 - 123.7 ± 11.1b; ISin - 98.4 ± 6.4c; IVM - 73.1 ± 4.9d. The mean H and standard deviation values (kg/mm²) and statistical grouping were D250 - 98.12 ± 1.8a; D350 - 86.5 ± 1.9b; ISin - 28.3 ± 0.9c; IVM - 30.8 ± 1.0c. The direct composite systems examined produce higher mean óf and H values than the indirect composites, and the mean values of these properties were positively correlated (r = 0.91), confirming the study hypotheses.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Resistência à Tração
/
Teste de Materiais
/
Resinas Compostas
Idioma:
Inglês
Revista:
Braz. oral res
Assunto da revista:
Odontologia
Ano de publicação:
2009
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
University of Passo Fundo/BR
/
University of São Paulo/BR
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