Siqueira José F, Rôças Isabela N
Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, Brazil.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004 Jan;97(1):85-94. doi: 10.1016/s1079-2104(03)00353-6.
In this study, we aimed to investigate the occurrence of several microbial species in cases of failed endodontic therapy by means of the polymerase chain reaction (PCR). Study design Root canal samples were taken from 22 root-filled teeth with persistent periradicular lesions selected for re-treatment. DNA was extracted from the samples and analyzed for the presence of 19 microbial taxa by using the polymerase chain reaction.
All samples were positive for at least 1 of the target microbial species. Enterococcus faecalis was the most prevalent species-detected in 77% of the cases. The other most prevalent species were Pseudoramibacter alactolyticus (52%), Propionibacterium propionicum (52%), Dialister pneumosintes (48%), and Filifactor alocis (48%). Candida albicans was found in 9% of the samples. The mean number of species in samples filled up to 2 mm short of the radiographic apex was 3 (range, 1-5), whereas cases in which the filling was greater than 2 mm from the apex yielded a mean of 5 species (range, 2-11). This difference was statistically significant (P <.05).
Microorganisms occurred in all cases of root-filled teeth associated with periradicular lesions, which lends strong support to the assertion that treatment failures are rather of infectious etiology, caused by persistent or secondary intraradicular infections. E faecalis was the most prevalent species, followed by 4 other anaerobic species: P. alactolyticus, P. propionicum, D. pneumosintes, and F. alocis. All examined samples harbored at least 1 of the following gram-positive bacterial species: E. faecalis, P. alactolyticus, or P. propionicum.
在本研究中，我们旨在通过聚合酶链反应（PCR）调查根管治疗失败病例中几种微生物种类的出现情况。研究设计：从22颗选择重新治疗的有持续性根尖周病变的根管充填牙中采集根管样本。从样本中提取DNA，并使用聚合酶链反应分析19种微生物分类群的存在情况。
所有样本至少对1种目标微生物种类呈阳性。粪肠球菌是最常见的种类——在77%的病例中被检测到。其他最常见的种类是解乳糖假丁酸杆菌（52%）、丙酸丙酸杆菌（52%）、嗜肺戴阿李斯特菌（48%）和栖居纤毛菌（48%）。白色念珠菌在9%的样本中被发现。根管充填至距影像学根尖短2 mm以内的样本中微生物种类的平均数为3种（范围为1 - 5种），而根管充填距根尖超过2 mm的病例中微生物种类平均数为5种（范围为2 - 11种）。这种差异具有统计学意义（P <.05）。
在所有与根尖周病变相关的根管充填牙病例中均存在微生物，这有力支持了治疗失败相当程度上是由持续性或继发性根管内感染导致的感染性病因这一论断。粪肠球菌是最常见的种类，其次是其他4种厌氧菌：解乳糖假丁酸杆菌、丙酸丙酸杆菌、嗜肺戴阿李斯特菌和栖居纤毛菌。所有检测样本均含有以下革兰氏阳性菌中的至少1种：粪肠球菌、解乳糖假丁酸杆菌或丙酸丙酸杆菌。
