Martinho Frederico C, Gomes Brenda P F A
Department of Restorative Dentistry, Endodontic Division, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil.
J Endod. 2008 Mar;34(3):268-72. doi: 10.1016/j.joen.2007.11.015. Epub 2008 Jan 31.
This clinical study was conducted to quantify endotoxins and cultivable bacteria in teeth with pulp necrosis and apical periodontitis before and after chemomechanical preparation with 2.5% sodium hypochlorite (NaOCl) and to investigate the possible correlation of endotoxin and cultivable bacteria with the presence of clinical symptomatology. Twenty-four root canals were selected. Samples were collected before (s1) and after chemomechanical preparation (s2). Culture techniques were used to determine the colony-forming unit. A limulus amebocyte lysate (LAL) assay was used to quantify endotoxins (lipopolysaccharide, LPS). LPS and bacteria were detected in 100% of the initial samples (s1), with a median concentration of 139 endotoxin units/mL and 2.64 x 10(5) colony-forming units/mL, respectively. Higher levels of LPS were found in teeth with clinical symptomatology (p < .05). At s2, mean endotoxin reduction of 59.99% and mean bacterial load reduction of 99.78% were found. Our findings indicated that chemomechanical preparation with 2.5% NaOCl was moderately effective against bacteria but less effective against endotoxins in root canal infection. Furthermore, a statistically significant association was found between higher levels and clinical symptomatology.
本临床研究旨在量化牙髓坏死和根尖周炎患牙在使用2.5%次氯酸钠（NaOCl）进行化学机械预备前后的内毒素和可培养细菌，并研究内毒素和可培养细菌与临床症状之间可能的相关性。选取了24个根管。在化学机械预备前（s1）和预备后（s2）采集样本。采用培养技术确定菌落形成单位。使用鲎试剂法（LAL）测定来量化内毒素（脂多糖，LPS）。在100%的初始样本（s1）中检测到LPS和细菌，内毒素中位浓度分别为139内毒素单位/mL，菌落形成单位为2.64×10(5)/mL。有临床症状的患牙中LPS水平更高（p<0.05）。在s2时，内毒素平均减少59.99%，细菌载量平均减少99.78%。我们的研究结果表明，2.5%NaOCl进行化学机械预备对根管感染中的细菌有中度疗效，但对内毒素疗效较差。此外，高水平与临床症状之间存在统计学上的显著关联。
