Sousa Ezilmara L R, Martinho Frederico C, Leite Fabio R M, Nascimento Gustavo G, Gomes Brenda P F A
Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, State University of Campinas, UNICAMP, Piracicaba, São Paulo, Brazil; Department of Conservative Dentistry, Endodontics Division, Pelotas School of Dentistry.
Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, State University of Campinas, UNICAMP, Piracicaba, São Paulo, Brazil; Department of Restorative Dentistry, Endodontics Division, São Jose dos Campos Dental School, State University of São Paulo, UNESP, São Jose dos Campos, São Paulo, Brazil.
J Endod. 2014 Nov;40(11):1752-7. doi: 10.1016/j.joen.2014.06.019. Epub 2014 Sep 6.
This clinical study has investigated the antigenic activity of bacterial contents from exudates of acute apical abscesses (AAAs) and their paired root canal contents regarding the stimulation capacity by levels of interleukin (IL)-1 beta and tumor necrosis factor alpha (TNF-α) throughout the root canal treatment against macrophage cells.
Paired samples of infected root canals and exudates of AAAs were collected from 10 subjects. Endodontic contents were sampled before (root canal sample [RCS] 1) and after chemomechanical preparation (RCS2) and after 30 days of intracanal medication with calcium hydroxide + chlorhexidine gel (Ca[OH]2 + CHX gel) (RCS3). Polymerase chain reaction (16S rDNA) was used for detection of the target bacteria, whereas limulus amebocyte lysate was used to measure endotoxin levels. Raw 264.7 macrophages were stimulated with AAA exudates from endodontic contents sampled in different moments of root canal treatment. Enzyme-linked immunosorbent assays were used to measure the levels of TNF-α and IL-1 beta.
Parvimonas micra, Porphyromonas endodontalis, Dialister pneumosintes, and Prevotella nigrescens were the most frequently detected species. Higher levels of endotoxins were found in samples from periapical exudates at RCS1 (P < .005). In fact, samples collected from periapical exudates showed a higher stimulation capacity at RCS1 (P < .05). A positive correlation was found between endotoxins from exudates with IL-1 beta (r = 0.97) and TNF-α (r = 0.88) production (P < .01). The significant reduction of endotoxins and bacterial species achieved by chemomechanical procedures (RCS2) resulted in a lower capacity of root canal contents to stimulate the cells compared with that at RCS1 (P < .05). The use of Ca(OH)2 + CHX gel as an intracanal medication (RCS3) improved the removal of endotoxins and bacteria from infected root canals (P < .05) whose contents induced a lower stimulation capacity against macrophages cells at RCS1, RCS2, and RCS3 (P < .05).
AAA exudates showed higher levels of endotoxins and showed a greater capacity of macrophage stimulation than the paired root canal samples. Moreover, the use of intracanal medication improved the removal of bacteria and endotoxins from infected root canals, which may have resulted in the reduction of the inflammatory potential of the root canal content.
本临床研究调查了急性根尖脓肿（AAA）渗出物中的细菌成分及其配对的根管内容物的抗原活性，涉及在根管治疗过程中白细胞介素（IL）-1β和肿瘤坏死因子α（TNF-α）水平对巨噬细胞的刺激能力。
从10名受试者中收集感染根管和AAA渗出物的配对样本。在化学机械预备前（根管样本[RCS]1）、化学机械预备后（RCS2）以及用氢氧化钙+氯己定凝胶（Ca[OH]2 + CHX凝胶）进行根管内用药30天后（RCS3）采集牙髓内容物样本。采用聚合酶链反应（16S rDNA）检测目标细菌，而用鲎试剂检测内毒素水平。用根管治疗不同阶段采集的牙髓内容物中的AAA渗出物刺激Raw 264.7巨噬细胞。采用酶联免疫吸附测定法测量TNF-α和IL-1β水平。
微小单胞菌、牙髓卟啉单胞菌、嗜肺戴阿李斯特菌和变黑普雷沃菌是最常检测到的菌种。在RCS1时，根尖周渗出物样本中的内毒素水平较高（P <.005）。事实上，从根尖周渗出物中采集的样本在RCS1时显示出更高的刺激能力（P <.05）。发现渗出物中的内毒素与IL-1β（r = 0.97）和TNF-α（r = 0.88）产生之间存在正相关（P <.01）。与RCS1相比，化学机械操作（RCS2）使内毒素和细菌种类显著减少，导致根管内容物刺激细胞的能力降低（P <.05）。使用Ca(OH)2 + CHX凝胶作为根管内用药（RCS3）改善了感染根管内毒素和细菌的清除（P <.05），其内容物在RCS1、RCS2和RCS3时对巨噬细胞的刺激能力较低（P <.05）。
AAA渗出物显示出比配对的根管样本更高的内毒素水平和更强的巨噬细胞刺激能力。此外，根管内用药改善了感染根管中细菌和内毒素的清除，这可能导致根管内容物的炎症潜能降低。
