Bactericidal effect of different laser systems in the deep layers of dentin
Bactericidal effect of different laser systems in the deep layers of dentin
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DOI：
10.1002/lsm.20026
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发表时间：
2004-01-01
影响因子：
2.4
通讯作者：
Sperr, W
中科院分区：
文献类型：
--
作者：
Schoop, U;Kluger, W;Sperr, W
背景和目标：近年来，各种激光系统在激光辅助牙髓病学领域中变得重要，即Nd：YAG、二极管、Er：YAG和Er，Cr：YSGG激光器。到目前为止，已经进行了单独的研究，重点是各自的波长，其特定的杀菌能力，以及潜在的有用性是根管消毒。然而，目前在体外调查，进行比较这些激光系统在标准化条件下的杀菌效果，并得出结论后，他们的相对有效性在深层的dentin.Study设计/材料和方法：在总的，360片根牙本质的厚度为1毫米的纵向切割新鲜提取的人前磨牙。对样品进行蒸汽灭菌，随后接种大肠杆菌或粪肠球菌的悬浮液。孵育后，将样本随机分配至4个不同的受试激光系统。每个激光组由两种不同的操作设置和一个控制装置组成。牙本质样本从无菌侧通过牙本质进行“间接”激光照射，然后进行经典的定量微生物评价。为了评估在辐照过程中的温度升高，额外的测量进行了使用热电偶。结果：微生物学表明，所有的激光系统都能够显着减少两个测试菌株。在有效输出功率为1 W时，E.在大多数样品中，通过测试的波长，大肠杆菌至少减少了三个对数级，Er：YAG激光的最佳结果显示完全根除了大肠杆菌。大肠杆菌阳性率为75%。E.粪菌是根管的顽固入侵者，在1 W时细菌计数显示出微小的变化。使用1.5 W的较高设置，E.再次观察到所有激光系统，其中只有二极管和Er：YAG激光能够完全根除大肠杆菌。粪便在很大程度上。有没有显着的温度升高和杀菌effiction.Conclusions之间的关系：本研究表明，所有的波长调查是适合的消毒，甚至更深层的牙本质，并可能被证明构成有价值的工具，在国家的最先进的牙髓。(C)2004 Wiley-Liss，Inc.
Background and Objectives: In recent years, various laser systems have gained importance in the field of laser-assisted endodontics, namely the Nd:YAG, the diode, the Er:YAG, and the Er,Cr:YSGG laser. Individual studies have been carried out so far, focusing on the respective wavelength, its specific bactericidal capabilities, and potential usefulness is root-canal disinfection. The present in vitro investigation however, was performed to compare the microbicidal effect of these laser systems under standardized conditions and to draw a conclusion upon their relative effectiveness in the deep layers of dentin.Study Design/Materials and Methods: In total, 360 slices of root dentin with a thickness of 1 mm were obtained by longitudinal cuts of freshly extracted human premolars. The samples were steam sterilized and subsequently inoculated with a suspension of either Escherichia coli or Enterococcus faecalis. After the incubation, the samples were randomly assigned to the four different laser systems tested. Each laser group consisted of two different operational settings and a control. The dentinal samples underwent "indirect" laser irradiation through the dentin from the bacteria-free side and were then subjected to a classical quantitative microbiologic evaluation. To assess the temperature increase during the irradiation procedure, additional measurements were carried out using a thermocouple.Results: Microbiology indicated that all laser systems were capable of significant reductions in both test strains. At an effective output power of 1 W, E. coli was reduced by at least three log steps in most of the samples by the tested wavelengths, with the best results for the Er:YAG laser showing complete eradication of E. coli in 75% of the samples. E. faecalis, a stubborn invader of the root canal, showed minor changes in bacterial count at 1 W. Using the higher setting of 1.5 W, significant reductions of E. coli were again observed with all laser systems, where only the diode and the Er:YAG laser were capable of complete eradication of E. faecalis to a significant extent. There was no significant relation between the temperature increase and the bactericidal effect.Conclusions: The present study demonstrates that all the wavelengths investigated are suitable for the disinfection of even the deeper layers of dentin and may prove to constitute valuable tools in state-of-the-art endodontics. (C) 2004 Wiley-Liss, Inc.