IADR Abstract Archives
Bleaching Treatment with Chemical or Light Activation and Bonding Time on Shear Bond Strength
Objectives: This study evaluated the effect of in office bleaching protocols with chemical activation or light activation and also different interval bonding time on shear bond strength.
Methods: In this in vitro study, thirty four maxillary premolars were collected and randomly divided into two groups of activation which were chemical activation (CA) and light activation (LA). The CA group was bleached with 40% hydrogen peroxide (Opalescence Xtra Boost) and the LA group was bleached with 40% hydrogen peroxide and light activated. Each group divided into 3 groups: restored with nanohybrid composite resin 7 days (CA 7, LA 7), 10 days (CA 10, LA 10) and 14 days after bleaching treatment (CA 14, LA 14). The negative control group was not bleached. The shear bond strength test was performed using Universal Testing Machine with knife edge head of 0.5 mm/min. The data in MPa were subjected to two-way analysis of variance.
Results: The mean of each group CA 7, CA 10, CA 14 was (20.54(±1.42); 23.85(±1.86); 21.98(±2.38) and LA 7, LA 10, LA 14 was 22.71(±3.35); 23.49(±1.92); 22.84(±3.21). Two-way analysis of variance showed that there are no significant difference (p=0.629) between groups and for each group of activation (p=0.707) and for group of bonding time (p=0.200). The data also showed that shear bond strength of each group almost the same as negative control group. These result caused by the effect of bleaching already disappear on the 7th day.
Conclusions: Restoration with nanohybrid composite resin on bleached enamel, either with chemical activation or light activation, after minimum of seven days interval gave shear bond strength as good as non-bleached enamel.
Methods: In this in vitro study, thirty four maxillary premolars were collected and randomly divided into two groups of activation which were chemical activation (CA) and light activation (LA). The CA group was bleached with 40% hydrogen peroxide (Opalescence Xtra Boost) and the LA group was bleached with 40% hydrogen peroxide and light activated. Each group divided into 3 groups: restored with nanohybrid composite resin 7 days (CA 7, LA 7), 10 days (CA 10, LA 10) and 14 days after bleaching treatment (CA 14, LA 14). The negative control group was not bleached. The shear bond strength test was performed using Universal Testing Machine with knife edge head of 0.5 mm/min. The data in MPa were subjected to two-way analysis of variance.
Results: The mean of each group CA 7, CA 10, CA 14 was (20.54(±1.42); 23.85(±1.86); 21.98(±2.38) and LA 7, LA 10, LA 14 was 22.71(±3.35); 23.49(±1.92); 22.84(±3.21). Two-way analysis of variance showed that there are no significant difference (p=0.629) between groups and for each group of activation (p=0.707) and for group of bonding time (p=0.200). The data also showed that shear bond strength of each group almost the same as negative control group. These result caused by the effect of bleaching already disappear on the 7th day.
Conclusions: Restoration with nanohybrid composite resin on bleached enamel, either with chemical activation or light activation, after minimum of seven days interval gave shear bond strength as good as non-bleached enamel.