Effect of light-activation methods and water storage on the flexural strength of two composite resins and a compomer

Leonardo Eloy Rodrigues Filho, Luis Antônio dos Santos Burger, Silvia Kenshima, José Roberto de Oliveira Bauer, Igor Studart Medeiros, Antonio Muench
2006 Brazilian Oral Research  
The present study evaluated the flexural strength of three composite resins recommended for direct esthetic restorations: a polyacid modified composite (Dyract AP), a unimodal composite resin (Filtek Z250) and a hybrid composite resin (Point 4). The variation factors, apart from the type of composite resin, were the light activation method and the water storage period. The composite resins were light-cured in continuous mode (40 s, 500 mW/cm²) or in ramp mode (0-800 mW/cm² for 10 s followed by
more » ... r 10 s followed by 30 s at 800 mW/cm²) and stored for 24 hours or 30 days in distilled water at 37°C. The data were analyzed by ANOVA and Tukey test for multiple comparisons (alpha = 0.05). The composite resin Z250 presented the highest mean flexural strength (166.74 MPa) and Dyract AP presented the lowest one (129.76 MPa). The storage for 30 days decreased the flexural strength in ramp mode (24 h: 156.64 MPa; 30 days: 135.58 MPa). The light activation method alone did not lead to different flexural strength values.
doi:10.1590/s1806-83242006000200010 pmid:16878208 fatcat:7v6sfu5mozcmjmaocca5626s4q