Comparison of the effect of bleaching with 15% carbamide peroxideand 35% hydrogen peroxide on flexural strength of Cention N in selfcuredand dual-cured polymerization modes

Abstract

Background. The use of bleaching agents might result in microstructural changes in tooth structure andin restorative materials. This study compared the effects of bleaching with %15 carbamide peroxide and%35 hydrogen peroxide on the flexural strength of Cention N restorative material using the self-curedand dual-cured polymerization modes. Methods. Sixty bar-shaped samples of Cention N restorative material were included in this in vitrostudy and assigned to three groups (n=20) randomly: control, bleaching with %15 carbamide peroxideand bleaching with %35 hydrogen peroxide. Each group was divided into two subgroups: samplespolymerized in the self-cured mode and samples polymerized in the dual-cured mode. Then the flexuralstrengths of the samples were determined. Two-way ANOVA was used to compare flexural strengthsbetween the three groups in two polymerization modes, followed by post hoc Tukey test. Statisticalsignificance was defined at P<0.05. Results. The difference in the mean flexural strength was significant in terms of the bleaching regimen(P<0.001), with significantly lower flexural strength in the two bleaching groups compared to thecontrol group. However, the mean flexural strengths were not significantly different in terms of thepolymerization mode applied (P=0.14). Conclusion. The application of %15 carbamide peroxide and %35 hydrogen peroxide bleaching agentsdecreased the flexural strength of Cention N restorative material. Irrespective of the bleaching regimen,there was no significant difference in the flexural strength of Cention N between the self-curing anddual-curing polymerization modes.

Keywords

• composite resins
• dental materials
• flexural strength
• tooth bleaching
• tooth bleaching agents