Giardino Luciano, Generali Luigi, Savadori Paolo, Barros Mirela Cesar, de Melo Simas Leticia Lobo, Pytko-Polończyk Jolanta, Wilkoński Wojciech, Ballal Vasudev, Andrade Flaviana Bombarda de
Independent Researcher, 88900 Crotone, Italy.
Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, 41124 Modena, Italy.
Dent J (Basel). 2022 Aug 9;10(8):148. doi: 10.3390/dj10080148.
There has been no unanimity concerning the ideal concentration of citric acid for safe use in clinical practice. This study evaluated the cytotoxicity and the antibacterial activity in infected dentinal tubules of 10% and 1% citric acid (CA) solutions.
The cytotoxicity of CA solutions in DMEM (diluted 1/10, 1/100) was assessed in L-929 fibroblasts. A broth macrodilution method (MIC and MBC) was used to assess CA antibacterial concentration. The antimicrobial activity of CA solutions was also evaluated after their final rinse inside root canals in previously -contaminated dentinal tubules. Ten infected dentine samples were rinsed for 5 min with 5% NaOCl and subsequently with 1% citric acid for 3 min. Another 10 were rinsed with 5% NaOCl and 10% citric acid for 3 min; the remaining four specimens were utilized as positive controls. Two uncontaminated specimens were used as negative controls. After LIVE/DEAD BacLight staining, the samples were assessed using CLSM to analyze the percentage of residual live and dead cells.
Both undiluted and diluted CA solutions showed severe toxicity; no changes from normal morphology were displayed when diluted 1/100. The MIC and MBC of CA were 6.25 mg/mL and 12.50 mg/mL, respectively. CA solutions demonstrated significantly low levels of bacterial counts than the positive control group, reporting a value of 9.3% for the 10% solution versus the 1% solution (35.2%).
Despite its valuable antimicrobial properties, the cytotoxic effects of citric acid should be considered during endodontic treatment.
关于临床实践中安全使用的理想柠檬酸浓度尚无一致意见。本研究评估了10%和1%柠檬酸（CA）溶液在感染牙本质小管中的细胞毒性和抗菌活性。
在L-929成纤维细胞中评估CA溶液在DMEM（稀释1/10、1/100）中的细胞毒性。采用肉汤稀释法（MIC和MBC）评估CA抗菌浓度。在先前污染的牙本质小管中进行根管内最终冲洗后，也评估了CA溶液的抗菌活性。10个感染牙本质样本先用5%次氯酸钠冲洗5分钟，随后用1%柠檬酸冲洗3分钟。另外10个样本先用5%次氯酸钠冲洗，再用10%柠檬酸冲洗3分钟；其余4个样本用作阳性对照。2个未污染的样本用作阴性对照。进行LIVE/DEAD BacLight染色后，使用共聚焦激光扫描显微镜（CLSM）评估样本，以分析残留活细胞和死细胞的百分比。
未稀释和稀释的CA溶液均显示出严重毒性；稀释1/100时未显示出与正常形态的差异。CA的MIC和MBC分别为6.25毫克/毫升和12.50毫克/毫升。CA溶液的细菌计数水平明显低于阳性对照组，10%溶液的细菌计数为9.3%，而1%溶液为35.2%。
尽管柠檬酸具有宝贵的抗菌特性，但在牙髓治疗过程中应考虑其细胞毒性作用。
