模拟髓腔压力下牙本质深度对粘接系统剪切强度影响的比较研究

摘要

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.%目的: 在模拟髓腔压力条件下,比较不同粘接系统对不同深度牙本质层的剪切强度的影响.方法: 72颗无龋第三磨牙截冠暴露成36颗牙本质浅层和36颗牙本质深层并随机分至3个不同粘接剂亚组(Prime&Bond NT,PB;Clearfil SE Bond, SE;Clearfil S3 Bond,S3;n = 12).在模拟髓腔压力下,3个亚组样本分别采用不同的粘接剂进行树脂充填,然后涂抹指甲油封闭样本,储存于模拟髓腔压力装置,24 h后测试剪切强度.结果: 3种粘接剂在浅层和深层的粘接强度分别为: PB组(17. 11 ± 2. 71) MPa和(11. 13 ± 3. 60) MPa(P ＜ 0. 05);SE(16. 53 ± 5. 29) MPa和(14. 78 ± 4. 53) MPa(P＞ 0. 05);S3(9. 08 ± 1. 74) MPa和(8. 43 ± 1. 41) MPa(P＞ 0. 05).结论: 在模拟髓腔压力条件下,不同深度牙本质对全酸蚀粘接剂的剪切强度有明显影响,对自酸蚀粘接剂的剪切强度无显著影响.