ABSTRACT
Objective: To determine the shear bond strength of different adhesive systems to superficial and deep dentin under simulated pulpal pressure. Methods: Occlusal surfaces of 72 sound extracted noncarious human molars were ground to obtain flat dentin surfaces(36 superficial and 36 deep dentin). Each dentin groups was randomly asssigned into 3 groups(n = 12): Clearfil SE Bond(SE), Clearfil S3 Bond(S3) and Prime&Bond NT(PB). All of samples were tested under simulated pulpal pressure. After bonding procedures with 3 adhesives respectively,all samples were covered with nail vanishi. The shear bond strength was tested after the samples stored for 24 h under simulated pulpal pressure. Results: The bond strength of PB to superficial and deep was (17. 11 ± 2. 71) and(11. 13 ± 3. 60) MPa(P ＜ 0. 05),that of SE (16. 53 ± 5. 29) and (14. 78 ± 4. 53) MPa(P＞ 0. 05),S3 (9. 08 ± 1. 74) and (8. 43 ± 1. 41) MPa(P＞ 0. 05). Conclusion: Bond strengths of phosphoric acid etching system decreases with an increase of dentin depth, that of two-step self-etch adhesive system is not affected by the depth.