Siqueira José F, Rôças Isabela N, Paiva Simone S M, Guimarães-Pinto Tatiana, Magalhães Karen M, Lima Kenio C
Estácio de Sá University, Rio de Janeiro, RJ, Brazil.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007 Jul;104(1):122-30. doi: 10.1016/j.tripleo.2007.01.027. Epub 2007 May 11.
This clinical study was undertaken to compare the effectiveness of 2.5% sodium hypochlorite (NaOCl) and 0.12% chlorhexidine digluconate as irrigants in reducing the cultivable bacterial populations in infected root canals of teeth with apical periodontitis.
According to stringent inclusion/exclusion criteria, 32 teeth with primary intraradicular infections and chronic apical periodontitis were selected and followed in the study. Bacterial samples were taken at the baseline (S1) and after chemomechanical preparation using either NaOCl (n = 16) or chlorhexidine (n = 16) as irrigants (S2). Cultivable bacteria recovered from infected root canals at the 2 stages were counted. Isolates from S2 samples were identified by means of 16S rRNA gene sequencing analysis.
At S1, all canals were positive for bacteria, and the median number of bacteria per canal was 7.32 x 10(5) for the NaOCl group and 8.5 x 10(5) for the chlorhexidine group. At S2, the median number of bacteria in canals irrigated with NaOCl and chlorhexidine was 2.35 x 10(3) and 2 x 10(2), respectively. Six of 16 (37.5%) canals from the NaOCl group and 8 of 16 (50%) canals from the chlorhexidine group yielded negative cultures. Chemomechanical preparation using either solution substantially reduced the number of cultivable bacteria in the canals. No significant difference was observed between the NaOCl and chlorhexidine groups with regard to the number of cases yielding negative cultures (P = .72) or quantitative bacterial reduction (P = .609). The groups irrigated with NaOCl or chlorhexidine showed a mean number of 1.3 and 1.9 cultivable species per canal, respectively. The great majority of isolates in S2 were from gram-positive bacteria, with streptococci as the most prevalent taxa.
The present findings revealed no significant difference when comparing the antibacterial effects of 2.5% NaOCl and 0.12% chlorhexidine used as irrigants during the treatment of infected canals.
本临床研究旨在比较2.5%次氯酸钠（NaOCl）和0.12%葡萄糖酸氯己定作为冲洗剂在减少根尖周炎患牙感染根管内可培养细菌数量方面的有效性。
根据严格的纳入/排除标准，选取32颗患有原发性根管内感染和慢性根尖周炎的牙齿并纳入本研究。在基线期（S1）以及使用NaOCl（n = 16）或氯己定（n = 16）作为冲洗剂进行化学机械预备后（S2）采集细菌样本。对两个阶段从感染根管中分离出的可培养细菌进行计数。通过16S rRNA基因测序分析对S2样本中的分离菌进行鉴定。
在S1时，所有根管细菌检测均为阳性，NaOCl组每根管细菌数量中位数为7.32×10⁵，氯己定组为8.5×10⁵。在S2时，用NaOCl和氯己定冲洗的根管中细菌数量中位数分别为2.35×10³和2×10²。NaOCl组16根根管中有6根（37.5%）培养结果为阴性，氯己定组16根根管中有8根（50%）培养结果为阴性。使用任何一种溶液进行化学机械预备均显著减少了根管内可培养细菌的数量。在培养结果为阴性的病例数（P = 0.72）或细菌数量减少量（P = 0.609）方面，NaOCl组和氯己定组之间未观察到显著差异。用NaOCl或氯己定冲洗的组每根管可培养菌种的平均数分别为1.3种和1.9种。S2中绝大多数分离菌为革兰氏阳性菌，其中链球菌是最常见的分类群。
本研究结果显示，在治疗感染根管时，比较2.5% NaOCl和0.12%氯己定作为冲洗剂的抗菌效果，未发现显著差异。
