低温常压等离子体改善牙本质-全酸蚀粘接系统粘接效果的体外研究

In Vitro Study of Non-thermal Atmospheric Pressure Plasma in Improving the Bonding Effect of Dentin with an Etch-and-rinse System

目的:本研究拟观测低温常压等离子体射流处理对牙本质-全酸蚀粘接系统粘接效果及牙本质胶原纤维耐NaClO降解的效果。方法:离体牙去除牙合面牙釉质,暴露的牙本质打磨后酸蚀15s并冲洗,随后用NTAPP射流分别处理牙面0、5、10、15、20s,常规制作微拉伸粘接试件,每组有一半试件冷热循环10 000次,分别检测各组循环前后牙本质粘接强度。获取中层牙本质片,酸蚀后经NTAPP处理0、5、10、15、20s后,分别浸泡于5% NaClO溶液中0、30、60、120s,扫描电镜观察各组脱矿牙本质胶原的降解情况。对各组粘接强度进行统计分析。结果:所有NTAPP处理组的微拉伸粘结强度(Micro-tensile bond strength,μTBS)值均显著高于对照组;NTAPP处理5s组的μTBS值显著高于其他组;老化后NTAPP处理5s和10s组的μTBS值显著高于其他各组。扫描电镜观察脱矿胶原显示,随着NaClO溶液处理时间延长,各组牙本质胶原均呈现不同程度降解,对照组120s胶原完全消失,但NTAPP处理组仍可见胶原纤维残留。NTAPP处理5和10s经NaClO浸泡30s后,胶原纤维网结构完整。NTAPP处理15和20s,使部分胶原纤维凝结变性。结论:采用合适的参数及处理时间,NTAPP可有效保护牙本质胶原纤维并提高牙本质-全酸蚀粘接界面的耐久性。

Objective To evaluate the bonding effect of non-thermal atmospheric pressure plasma treatment on the dentin-adhesive interface with an etch-and-rinse system and the degradation resistance of collagen under the sodium hypochlorite(NaClO)challenge.Methods The occlusal enamel of each tooth was removed.The exposed and polished dentin surface was etched for 15s and rinsed.The etched dentin surface was exposed to the plasma jet for 0,5,10,15,20s.Then the micro-tensile bonding specimens were made following the method described previously.Half of the specimens in each group were thermo-cycled 10000 times.The micro-tensile bonding specimens from each tooth were subjected toμTBS testing.The dentin slabs of middle part from each tooth were treated with plasma jet for 0,5,10,15,20s after etched,and further immersed in 5%NaClO solution for different treatment times(0,30,60 and 120s).All specimens were observed under FE-SEM.The results ofμTBS were analyzed with SPSS.Results TheμTBS values of all NTAPP treatment groups were significantly increased compared with the control group.The T-5 group presented statistically higherμTBS values than any other groups.After thermocycling aging,theμTBS values of 5 and 10s groups were significantly higher than those of the other groups.Collagen fibrils presented with various levels of degradation in each group,with increasing NaClO treatment time.After NaClO treatment for 120s,the collagen fibrils of control group were completely degraded.However,residue collagen fibrils were still observed in the NTAPP treatment group.Collagen fibrils of 5 and 10s groups presented well-formed open networks after NaClO treatment for 30s.After NTAPP treatment for 15 and 20s,some demineralized collagen fibrils were melted and degenerated.Conclusion Under optimal in vitro conditions,NTAPP treatment is effective in enhancing the dentin–bonding strength,improving the durability of the dentin–adhesive interface,and modifying the degradation resistance of collagen under NaClO challenge.