根管预备的直径不同对超声根管冲洗效果影响的SEM研究

Effect of ultrasonic root canal irrigation on different diameters of root canal preparation through SEM

关键词:  超声根管冲洗  根管扩锉直径  NaClO  玷污层  扫描电镜

Key words:  ultrasonic root canal irrigation  the diameters of root canal preparation  NaClO  smear layer  scanning electron microscope

摘要:

［目的］观察离体牙根管预备冲洗后根管壁残存碎屑量以及牙本质小管口直径，探讨在超声根管冲洗中,根管预备的直径不同对根管冲洗效果的影响。［方法］将60颗离体牙随机分成 A1、A2、A3和B1、B2、B3六组，每组10颗牙，进行预备和冲洗。A组以注射器冲洗，B组以超声波冲洗。根管冲洗液均使用5.25% NaClO溶液。制作扫描电镜标本，评价根管壁牙本质表面残存碎屑量、测量牙本质小管口直径。［结果］① 残存碎屑量A1、A2、A3三组在根管的冠1/3、中1/3、和尖1/3均有大量碎屑残存。超声冲洗组，根管壁玷污层被去除，牙本质小管口暴露。A1、A2、A3三组与 B1、B2、B3三组在根管冠1/3、中1/3、尖1/3三部位的残存碎屑量比较，差异有显著性意义（P<0.05）。B1、B2、B3三组在根管冠1/3、中1/3和尖1/3的残存碎屑量，差异无显著性意义（P>0.05）。②B1、B2、B3三组间在冠1/3、中1/3、尖1/3三部位的牙本质小管口直径，差异有显著性意义（P<0.05）；每两组间比较，差异有显著性意义（P<0.05）。［结论］使用相同剂量的NaClO溶液时,在去除根管壁牙本质表面玷污层和根管壁牙本质表面碎屑的效果上，超声根管冲洗优于人工注射器冲洗。在超声根管冲洗中，增大根管预备的直径能提高冲洗液去除玷污层的效果。超声根管冲洗以NaClO为冲洗液时，对牙本质小管口及管周牙本质没有造成过度脱矿和蚀刻。

Abstract:

［Objective］To observe the debris quantities and diameters of dentinal tumble openings of the surface of root canal walls in the extracorporeal teeth through SEM, and to explore the effect of root canal irrigation in different diameters of root canal preparation by the ultrasonic rrigation through SEM.［Methods］Sixty extracorporeal teeth were divided into six groups randomly named A1,A2,A3, and B1,B2,B3. There were ten teeth in every group. Reamed and filed the root canals by handed stainless steel K-file.A1,A2,A3 groups were irrigated by injector while B1,B2,B3 groups were irrigated by ultrasonic irrigation. The cleaning liquidwas 5.25% NaClO.Prepared SEM specimens. Estimated debris quantities in inner walls of root canals, and measured the diameters of dentinal tubule openings.［Results］1. Debris quantities: Compared the debris quantities of different regions of root canals of groups after the ultrasonic root canal irrigation: there was no significant difference among B1,B2,B3 groups (P>0.05). Compared the debris quantities of different groups: there was a significant difference between A1,A2,A3 groups and B1,B2,B3 groups(P<0.05).2. Diameters of dentinal tumble openings: recorded the diameters of dentinal tumble openings of different regions on root canals: There was a significant difference among these three groups and there was a significant difference between every two groups(P<0.05).［Conclusions］Clearing smear layer on the surface of dentine and cleaning the debris on the surface of dentine at any region of root canal when the same dose of NaClO is used as cleaning liquid. Ultrasonic root canal irrigation had the synergism with NaClO.Enlarging the diameters of root canal preparation could improve the ability of clearing the smear layer at any region of the root canals. Using NaClO as the cleaning liquid during ultrasonic root canal irrigation neither cause excessive demineralization nor etch to the inner walls of root canal and peritubular dentine.