Authors: Eduardo Moreira da Silva Laiza Tatiana Poskus José Guilherme Antunes Guimarães Alexandre de Araújo Lima Barcellos Carlos Eduardo Fellows
Publish Date: 2007/08/01
Volume: 19, Issue: 3, Pages: 1027-1032
Abstract
This study analyzed the influence of light polymerization modes on crosslink density CD and the degree of conversion DC of dental composites A minifilled hybrid and a nanofilled dental composite were photoactivated with two light polymerization modes Conventional—850 mW/cm2 for 20 s and Gradual—50 up to 1000 mW/cm2 for 10 s + 1000 mW/cm2 for 10 s DC was determined by the use of FTRamanspectrometer A softening test using Knoop diamond indentation was carried out at the top and bottom of 2 mm thick dental composite disks before and after storage in 100 ethanol for 24 h in order to represent the amount of crosslink density Data were analyzed by ANOVA and Student–Newman–Keuls’ multiple range test α = 005 The DC was influenced by light polymerization modes with Gradual mode presenting lower DC On bottom surfaces the nanofilled dental composite was more susceptible to softening by ethanol than minifilled hybrid and gradual light polymerization of nanofilled dental composite resulted in more softening than when conventional light polymerization was used The results suggest that nanofilled composites are capable undergoing more plasticization if applied in thick increments
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