Effects of bleaching agents on three different bonding agents in Cl.V composite resin restoration (in vitro comparative study)

Abstract

Bleaching the discolored teeth may affect the tooth/composite interface. Thisaction found to be differing when different bonding agents were used.Aim of the study was to evaluate the effect of vital tooth bleaching onmicroleakage of existent class V composite resin restorations bonded with three dentalbonding agents.Class V cavities were prepared on buccal surfaces of 60 intact, extracted humanmandibular premolar teeth with gingival margins in cementum and occlusal marginsin enamel, then these 60 teeth were randomly divided into 3 groups. Cavities in eachgroup were treated with one of the following bonding agents: AdperTM Single BondPluse Adhesive (3M-ESPE) [group A], Tetric N-Bond (ivoclar, vivadent) [group T]and Stae (SDI) [group S]. All teeth were restored with Tetric N-Ceram light activatedcomposite material. Each group was equally subdivided into control [AC, TC and SC]and bleached [AB, TB and SB] subgroups (n = 10). The bleached subgroups werebleached with 8% carbamide peroxide (Pola Paint, SDI, Australia) for 30 minutestwice a day for 14 days (according to the manufacturer's instruction). Microleakagescores were evaluated on the incisal and cervical walls. Data were analyzed usingPaired –Samples t- test.Bleaching with carbamide peroxide paint significantly increased the microleakageof composite restorations in Stae group at dentinal walls (P ≤0.05). Bleaching had noeffect on microleakage of restorations in the AdperTM Single Bond Plus Adhesive andTetric N-Bond groups.Vital tooth bleaching with carbamide peroxide paint has an adverse effect onmarginal seal of dentinal walls of existent composite resin restorations bonded withStae adhesive