Bond strength of self-etching adhesives to bleached pulp chamber dentin

Objective: The purpose of this study was to compare the shear bond strength of two self-etching adhesives: Clearfil SE Bond (Kurarey, Japan) and Adper Prompt (3M ESPE, USA) to pulp chamber dentin with and without calcium hydroxide (Ca(OH)2) dressing following walking bleach. Methods: Eighty extracted human maxillary premolars were used for the study. Conventional endodontic treatment and walking bleach (sodium perborate/water, 7 days) were performed.  Specimens were randomly assigned into 4 groups (n=20 each): Group 1 (CoSE): without Ca(OH)2 (cotton pellet), Clearfil SE Bond, Group 2 (CoAP): without Ca(OH)2, Adper Prompt, Group 3 (CaSE): with Ca(OH)2, Clearfil SE Bond, and Group 4 (CaAP): with Ca(OH)2, Adper Prompt. Pulp chambers were dressed with Ca(OH)2 or cotton pellet for 7 days, then restored with composite-resin (Z100, 3M ESPE, USA) using adhesives.  All teeth were stored in artificial saliva (37C, 100% humidity, 24 h). To prepare the 3x3 mm specimens, all crowns were cut vertically in a mesio-distal direction, 2 mm coronal to cemento-enamel junction. Shear bond strengths were determined using universal testing machine. Statistical analysis was performed using Two-way ANOVA at 95% confidence interval. Results: Mean shear bond strengths are presented in table. There was no significant difference in mean shear bond strengths between groups with or without Ca(OH)2 dressing (p=0.43). Comparing between different adhesives, the mean shear bond strength of Adper Prompt was significantly higher than that of Clearfil SE Bond (p=0.021).

Conclusions: Adper Prompt had a significantly higher shear bond strength to pulp chamber dentin than Clearfil SE Bond. Application of calcium hydroxide dressing following walking bleach had no effect on shear bond strengths of the two self-etching adhesives.