Zandi Homan, Rodrigues Renata C V, Kristoffersen Anne K, Enersen Morten, Mdala Ibrahimu, Ørstavik Dag, Rôças Isabela N, Siqueira José F
Department of Endodontics, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway; Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway.
Department of Endodontics, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
J Endod. 2016 Sep;42(9):1307-13. doi: 10.1016/j.joen.2016.06.006. Epub 2016 Jul 21.
This study compared the antibacterial effects of 1% sodium hypochlorite (NaOCl) and 2% chlorhexidine digluconate (CHX) during retreatment of teeth with apical periodontitis.
Root canal-treated teeth with apical periodontitis were randomly distributed into 2 groups. Bacteriological samples were taken from the canals before (S1) and after (S2) preparation using either NaOCl or CHX irrigation and after calcium hydroxide medication (S3); 16S ribosomal RNA gene-based real-time quantitative polymerase chain reaction was performed to quantify total bacteria, streptococci, and Enterococcus faecalis.
Forty-nine teeth were available for analysis (NaOCl, n = 20; CHX, n = 29). Bacterial DNA occurred in all S1 samples, streptococci in 57% and E. faecalis in 6%. The total bacterial counts decreased from S1 to S2 in both groups (P < .01) but were higher in S3 than S2 (P < .01). Thirty-five percent of the teeth in the NaOCl group were positive in S2, decreasing to 20% in S3. In the CHX group, 41% were positive in S2, decreasing to 31% in S3. The bacterial load in S1 influenced the incidence of bacteria in S2 (P < .01). Streptococci were significantly reduced in both groups, and E. faecalis was found in only 1 S2 sample and not in S3. No significant difference between NaOCl and CHX was found.
NaOCl and CHX both reduced bacterial counts and the number of infected canals. Intracanal medication with calcium hydroxide reduced the number of canals with persistent infection but resulted in overall larger bacterial counts in the cases positive for bacteria. The effectiveness of antimicrobial treatment can be influenced by the initial bacterial load.
本研究比较了1%次氯酸钠（NaOCl）和2%葡萄糖酸氯己定（CHX）在根尖周炎患牙再治疗过程中的抗菌效果。
将患有根尖周炎且已进行根管治疗的牙齿随机分为2组。在使用NaOCl或CHX冲洗根管之前（S1）、之后（S2）以及氢氧化钙药物治疗之后（S3），从根管中采集细菌学样本；采用基于16S核糖体RNA基因的实时定量聚合酶链反应来定量总细菌、链球菌和粪肠球菌。
49颗牙齿可供分析（NaOCl组，n = 20；CHX组，n = 29）。所有S1样本中均存在细菌DNA，其中链球菌占57%，粪肠球菌占6%。两组中从S1到S2总细菌计数均下降（P <.01），但S3中的总细菌计数高于S2（P <.01）。NaOCl组35%的牙齿在S2时呈阳性，在S3时降至20%。CHX组中，S2时41%呈阳性，在S3时降至31%。S1中的细菌载量影响S2中细菌的发生率（P <.01）。两组中的链球菌均显著减少，且仅在1个S2样本中发现粪肠球菌，S3样本中未发现。未发现NaOCl和CHX之间存在显著差异。
NaOCl和CHX均降低了细菌计数和感染根管的数量。根管内使用氢氧化钙减少了持续感染根管的数量，但在细菌阳性的病例中导致总体细菌计数更高。抗菌治疗的有效性可能受初始细菌载量的影响。
