ABSTRACT
To evaluate the initial shear bond strengths (SBSs) of ceramic brackets using either a self-etching primer (SEP) or the conventional method (CM) after intracoronal bleaching with sodium perborate and distilled water.
Eighty human incisors were divided into four groups according to bleaching and bonding procedures: Group 1, bleaching was not applied and the brackets were bonded with a self-etching primer; Group 2, bleaching was not applied and the brackets were bonded with the conventional method; Group 3, intracoronal bleaching with sodium perborate was applied for three weeks and the brackets were bonded with a self-etching primer; and Group 4, intracoronal bleaching with sodium perborate was applied for three weeks and the brackets were bonded with the conventional method. A self-etching primer (Transbond Plus) was applied as recommended by the manufacturer. After SEP application, the ceramic brackets were bonded with a light-curing adhesive (Transbond XT). For the conventional method, the teeth were etched with 37% phosphoric acid. After etching, a thin uniform coat of primer (Transbond XT Primer) was applied and the ceramic brackets were bonded with a light-curing adhesive (Transbond XT). SBSs were measured after water storage for 30 days, after 1000 cycles of thermocycling between 5°C and 55°C. Bond failure location was determined with the Adhesive Remnant Index (ARI).
For the SEP method, there was no significant difference between SBS values of the bleaching and non-bleaching groups. Furthermore, for the conventional method, the SBS value of the non-bleaching group was not significantly different from that of the bleaching group. SBS values of the SEP method presented significant differences from those of the conventional method (p<0.001). SBS values of SEP application decreased with and without bleaching. The ARI scores did not show any significant difference among the groups (p=0.174).
Intracoronal bleaching with sodium perborate and distilled water did not affect the SBS values of ceramic brackets.
