Gomes B P F A, Souza S F C, Ferraz C C R, Teixeira F B, Zaia A A, Valdrighi L, Souza-Filho F J
Endodontic Department, Piracicaba Dental School, State University of Campinas-UNICAMP, Piracicaba, SP, Brazil.
Int Endod J. 2003 Apr;36(4):267-75. doi: 10.1046/j.1365-2591.2003.00634.x.
To evaluate the effectiveness of 2% chlorhexidine gluconate gel and calcium hydroxide (Ca(OH)2) as intracanal medicaments against Enterococcus faecalis.
One hundred and eighty dentine tubes prepared from intact freshly extracted bovine maxillary central incisors were infected in vitro for 7 days with E. faecalis. The specimens were divided into four groups, according to the intracanal medicament used, as follows: Group 1: 2% chlorhexidine gluconate gel; Group 2: calcium hydroxide in a viscous vehicle (polyethyleneglycol 400); Group 3: 2% chlorhexidine gluconate gel + calcium hydroxide and Group 4: Brain Heart Infusion (BHI) broth (control group). The medicaments were placed into the canal lumen and left there for experimental times of 1, 2, 7, 15 and 30 days. After each period, irrigation with sterile saline to remove the medicament was performed and the canals were dried with sterile paper points. Dentine chips were removed from the canals with sequential sterile round burs at low speed. The samples obtained with each bur were immediately collected in separate test tubes containing BHI broth. The tubes were incubated at 37 degrees C and daily observed for microbial growth, visualized by the medium turbidity.
Chlorhexidine gel alone completely inhibited the growth of E. faecalis after 1, 2, 7 and 15 days. Calcium hydroxide allowed microbial growth at all experimental times. The combination of chlorhexidine and Ca(OH)2 was effective after 1 and 2 days demonstrating 100% antibacterial action; however, its antibacterial activity reduced between 7 and 15 days.
Under the conditions of this study, it can be concluded that 2% chlorhexidine gel alone was more effective against E. faecalis than calcium hydroxide (P < 0.05). However, its antibacterial activity depended on how long it remained inside the root canal.
评估2%葡萄糖酸氯己定凝胶和氢氧化钙（Ca(OH)₂）作为根管内药物对粪肠球菌的有效性。
用完整新鲜拔除的牛上颌中切牙制备180根牙本质小管，在体外感染粪肠球菌7天。根据所使用的根管内药物，将标本分为四组，如下：第1组：2%葡萄糖酸氯己定凝胶；第2组：含粘性赋形剂（聚乙二醇400）的氢氧化钙；第3组：2%葡萄糖酸氯己定凝胶+氢氧化钙；第4组：脑心浸液（BHI）肉汤（对照组）。将药物置于根管管腔内，并分别放置1、2、7、15和30天。每个时间段后，用无菌盐水冲洗以去除药物，并用无菌纸尖干燥根管。用连续的低速无菌圆钻从根管中取出牙本质碎屑。用每个钻头获得的样本立即收集在含有BHI肉汤的单独试管中。试管在37℃下孵育，每天观察微生物生长情况，通过培养基浊度进行可视化观察。
单独使用氯己定凝胶在1、2、7和15天后完全抑制了粪肠球菌的生长。氢氧化钙在所有实验时间均允许微生物生长。氯己定和Ca(OH)₂的组合在1天和2天后有效，显示出100%的抗菌作用；然而，其抗菌活性在7至15天之间降低。
在本研究条件下，可以得出结论，单独使用2%氯己定凝胶对粪肠球菌的效果比氢氧化钙更有效（P<0.05）。然而，其抗菌活性取决于它在根管内停留的时间。
