【摘要】 目的 :比较声波与超声波根管器械配合不同冲洗液预备根管的清理效果。方法 :制作根管扫描电镜标本 ,观察根管玷污层分布和牙本质小管暴露情况 ,各标本的冠 1/ 3、中 1/ 3、根尖 1/ 3区域各取 10个 5 0 0倍视野照相 ,分级评分 (玷污层分数 ,SL)。统计学分析比较三种冲洗液条件下声波和超声波器械根管清理的差异。结果 :仅以蒸馏水作冲洗液 ,声波不能有效清理碎屑与玷污层 ;2 5g/LNaClO冲洗 ,根尖 1/ 3玷污层的去除超声组优于声波组 ,但未清除玷污层栓层 ;2 5g/LNaClO结合 170g/LEDTA作冲洗液 ,玷污层去除显著且两组无显著差异 ,但根尖 1/ 3差于根管中上段 ,超声组部分区域牙本质小管蚀刻与融合。结论 :声波结合 2 5g/LNa ClO和 170g/LEDTA可有效去除玷污层并达到与超声器械近似的根管清理效果 ,根管内荡洗去除玷污层栓层效果显著 ,且未对根管壁产生破坏 ,但有必要加强根尖部荡洗。更多还原

【Abstract】 AIM:To investigate the cleaning efficiency of sonic endodontic instruments by observing the smear layer comparing to ultrasonic instruments.METHODS:The 48 canals were divided into six groups,instrumented by sonic or ultrasonic and irrigated after every instrumentation,once with water or 2 mL of 2.5% NaClO or a final flush with 17% EDTA.Roots were split longitudinally and prepared for SEM.The smear layer score(SL) was evaluated under 500 times magnification in three areas(apical, middle,and coronal of the root) by means of numerical evaluation scale.RESULTS:There were statistically significant differences between three groups with respect to smear layer score.In all groups a best cleaning smear layer was observed in a combination of EDTA and NaClO.Irrigated by NaClO only,the root canals,those had been enlarged with sonic,often featured a thick smear layer when compared with the ultrasonic instrumentation.The US group showed relatively thinner smear layer but with announced plugs in dentinal tubule.Combining the EDTA as final trrigation all groups achieved a cleaner efficacy that was hardly distinguishable from one another.Lots of dentinal tubule could be recognized.However the US group displayed widening of the tubules and erosion at the site of dentinal tubule openings in some area.CONCLUSION:By sonic instrumentation,the smear layer had been effectively reduced by EDTA,resulting an equivalent degree to ultrasonic group and without inducing erosion. [更多还原