Comparison of Shear Bond Strengths of Ceramic Brackets Using Either Self-etching Primer or Conventional Method After Intracoronal Bleaching

Abstract

Objective: 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. Methods: 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). Results: 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). Conclusion: Intracoronal bleaching with sodium perborate and distilled water did not affect the SBS values of ceramic brackets.

Effect of different intracoronal bleaching methods on shear bond strength of ceramic brackets bonded to bleached enamel: An in-vitro study

“…have also reported no significant difference in bond strength between bleached and unbleached enamel after 7 days and 30 days of bleaching. [ 8 11 ] The probable reason for this might be that those two studies had used sodium perborate mixed with distilled water as compared to our study where sodium perborate was mixed with hydrogen peroxide for bleaching. Abdulkareem et al ., explained that the insignificant effect of bleaching on the bond strength of ceramic brackets could be due to the following: (1) the presence of zirconia particles coating the bracket base creates millions of undercuts that secure the bracket in place, by micromechanical retention means, (2) due to the translucency that monocrystalline bracketsprovides, itgives a better chance for complete polymerization of the adhesive with light curing, (3) monocrystalline brackets are hard and offer great strength that prevents or reduces the peeling effects that may occur during brackets debonding, thus gives them high shear bond strength values.…”

“…Ceramic brackets demonstrate superior aesthetics, biocompatibility, and resistance to physical and chemical factors and are reported to have greater or equal bond strength as stainless steel brackets. [ 8 ] These brackets allow the curing light to transmit through them and thus there may be a better polymerization.…”