Huque J, Kota K, Yamaga M, Iwaku M, Hoshino E
Department of Operative Dentistry and Endodontics, Niigata University School of Dentistry, Japan.
Int Endod J. 1998 Jul;31(4):242-50. doi: 10.1046/j.1365-2591.1998.00156.x.
The study aimed to evaluate intracanal irrigation procedures in eradicating bacteria from surface, shallow and deep layers of root dentine using extracted human teeth. Artificial bacterial smear layer was successfully produced by rubbing a mixture of dental plaque and artificially decalcified dentine or carious dentine on root canal walls. The reservoir holes were 3.5 mm in depth, 1 mm in diameter prepared 1.5 mm apart and parallel to the root canals on the decrowned planes, in which five separate bacterial species were placed (Actinomyces israelii, Fusobacterium nucleatum, Propionibacterium acnes, Streptococcus mutans and Streptococcus sanguis). Bacterial eradication after irrigation of the prepared canals was determined by bacterial recovery (i) from the root canal surfaces and shallow layers where bacteria were smeared artificially and (ii) from deeper layers of root canal dentine reservoir holes. Ultrasonic irrigation with 5.5% and 12% NaOCl eradicated bacteria from artificial smear layer (P < 0.0001), whilst 12% NaOCl irrigation with a syringe was insufficient. Ultrasonic irrigation with water or 15% EDTA-failed to eradicate bacteria from smeared surfaces. Ultrasonic irrigation with 12% NaOCl killed A. israelii, F. nucleatum, P. acnes, S. mutans, and S. sanguis placed in reservoir channels, although for F. nucleatum, a very small number of bacteria remained in five samples out of 12. Ultrasonic irrigation with less concentrated NaOCl failed to eliminate bacteria completely from reservoir channels in most samples. Ultrasonic irrigation with 12% NaOCl appeared to eliminate bacteria efficiently from surface, shallow and deep layers of root dentine.
本研究旨在利用拔除的人牙评估根管冲洗程序在清除牙根牙本质表层、浅层和深层细菌方面的效果。通过将牙菌斑与人工脱矿牙本质或龋坏牙本质的混合物涂抹在根管壁上，成功制备了人工细菌涂片层。在去冠平面上，制备深度为3.5毫米、直径为1毫米、相距1.5毫米且与根管平行的储菌孔，在其中放置五种不同的细菌（以色列放线菌、具核梭杆菌、痤疮丙酸杆菌、变形链球菌和血链球菌）。通过细菌回收来确定对制备好的根管进行冲洗后的细菌清除情况：(i) 从人工涂抹细菌的根管表面和浅层；(ii) 从根管牙本质储菌孔的较深层。用5.5%和12%的次氯酸钠进行超声冲洗可从人工涂片层清除细菌（P < 0.0001），而用注射器注入12%的次氯酸钠冲洗则不足。用水或15%乙二胺四乙酸进行超声冲洗未能从涂抹表面清除细菌。用12%的次氯酸钠进行超声冲洗可杀死放置在储菌通道中的以色列放线菌、具核梭杆菌、痤疮丙酸杆菌、变形链球菌和血链球菌，不过对于具核梭杆菌，在12个样本中有5个样本残留了极少量细菌。用浓度较低的次氯酸钠进行超声冲洗在大多数样本中未能从储菌通道完全清除细菌。用12%的次氯酸钠进行超声冲洗似乎能有效清除牙根牙本质表层、浅层和深层的细菌。
