冷热循环影响不同粘接系统与纤维桩粘接强度的比较研究

摘要

目的:探讨冷热循环对不同粘接系统在不同桩道深度中粘接强度的影响.方法:选取32颗下颌第一前磨牙,常规根管充填并桩道预备后,选用全酸蚀+树脂粘接水门汀(A组)和自酸蚀+树脂粘接水门汀(B组)分别完成纤维桩粘接;每组又分为2个亚组(n=8),分别进行人工唾液存储24h(A0组、B0组),5℃-55℃冷热循环处理5000次(A1组、B1组);采用万能试验机分别测量各组在根上、根中和根尖部的粘接强度,扫描电镜观察粘接界面.结果:在根上部,A1组粘接强度(10.02±1.07MPa)大于B1组(8.62±1.12MPa)(P＜0.05);根中部和根下部,粘接强度B1组(7.98±0.47MPa,9.13±1.12MPa)大于A1组(2.98±0.76MPa,2.14±0.36MPa)(P＜ 0.05).冷热循环处理后,无论根上、根中和根下组,A0组大于A1组(P＜0.05);B0组大于B1组(P＜0.05).扫描电镜显示,A、B组粘接界面均可见树脂突和混合层结构,且B组混合层形态更加连续、致密.结论:桩道深度的增加会降低全酸蚀组的粘接强度,冷热循环会降低两种系统的粘接强度,但自酸蚀粘接系统相对全酸蚀粘接系统更可靠.%Objective:To discuss the effect of thermal cycle on the bond strength of glass fiber posts after different resin adhesive of different regions of root canal dentin.Methods:Thirty-two fresh human mandibular premolars were collected.After Conventional root canal filling and post-preparation.the fiber piles were bonded with total acid etching resin (group A) and self-etching resin bonded cement (group B) respectively.Each group is divided into 2 subgroups:Group A0 and group B0).They were treated with artificial saliva for 24h,respectively.The hot and cold cycles of 5℃-55℃ were performed 5000 times (group A1 and group B1).The universal testing machine was used to measure the bonding strength of fiber postsfor the upper,middle and apical parts of the root.And the bonding interface was observed by scanning electron microscope.Results:In the upper portion of the root,the bond strength in group A1 (10.02± 1.07MPa) was greater than that in group B1 (8.62± 1.12 MPa) (P＜0.05).For middle and lower portion of the root,the bond strength in group B1 and group B1 was (7.98±0.47MPa,9.13± 1.12MPa) was larger than that of group A1 (2.98±0.76MPa,2.14±0.36MPa) (P＜0.05).After hot and cold cycles,the groupA0 was greater than the A1 group (P＜0.05),while the B0 group was greater than the B1 group (P＜0.05) Scanning electron microscopy showed that resin bumps and mixed layer structures were observed at bonding interface of group A and group B.Conclusions:Thermal cycling could decrease the bond strengths of total-etch system and self-etch system.The self-etch system can show better bond strength than total-etch system.