The Effect of 15% Carbamide Peroxide Bleaching on the Shear Bond Strength of Composite to Enamel

Statement of problem: carbamide peroxide bleaching has been implicated toadversely affect the bond strength of composite to enamel.purpose: the purpose of this study was to evaluate the effect of carbamideperoxide bleaching on the shear bond strength of composite to bleached enamelbonded with a three step total etch system; scotchbond multipurpose(sbmp), andtwo simplified all-in-one systems; prompt l-pop (plp) and i bond.materials and methods: seventy two human molar teeth were randomlyassigned to three control and three experimental groups. the experimental groupswere subjected to a %15 carbamide peroxide bleaching system. twenty four hourslater, all the control and experimental groups were bonded with cylinders ofcomposite, using three dental bonding agents. after thermocycling, shear bondstrengths were determined by a universal testing machine. the data wereevaluated using one way anova and duncan tests (p<0.05).results: the composite bond strengths of sbmp were 19.52±5.21 mpa to theunbleached and 7.95±4.16 mpa to the bleached enamel. for plp, the unbleachedenamel exhibited bond strengths of 9.66±2.89 mpa and, the bleached one showeda bond strength value of 5.39±0.66 mpa. for i-bond the composite bond strengthswere 11.46±4.31 mpa to the unbleached and 6.41±2.01 mpa to the bleachedenamel. there was a statistically significant difference between the shear bondstrength of the control and experimental groups of each dental bonding agent(sbmp, p<0.001, plp, p<0.001, i bond: p=0.002).conclusion: bleaching with 15% carbamide peroxide used in this study reducedthe bond strengths of the composite to the enamel bonded with a three step totaletch and two simplified one step all-in-one dental bonding agents.