Department of Periodontology and Oral Implantology, Dental Research Division, Guarulhos University, Praça Tereza Cristina, 88, Centro, Guarulhos, SP, 07023-070, Brazil.
Department of Morphology, São Paulo State University (UNESP), School of Dentistry, Araraquara, São Paulo, Brazil.
Clin Oral Investig. 2021 Oct;25(10):5945-5953. doi: 10.1007/s00784-021-03900-0. Epub 2021 Mar 28.
This study evaluated the metabolic activity of hydro-carbon-oxo-borate complex (HCOBc) on a multispecies subgingival biofilm as well as its effects on cytotoxicity.
The subgingival biofilm with 32 species related to periodontitis was formed in the Calgary Biofilm Device (CBD) for 7 days. Two different therapeutic schemes were adopted: (1) treatment with HCOBc, 0.12% chlorhexidine (CHX), and negative control group (without treatment) from day 3 until day 6, two times a day for 1 min each time, totaling 8 treatments and (2) a 24-h treatment on a biofilm grown for 6 days. After 7 days of formation, biofilm metabolic activity was determined by colorimetry assay, and bacterial counts and proportions of complexes were determined by DNA-DNA hybridization. Both substances' cytotoxicity was evaluated by cell viability (XTT assay) and clonogenic survival assay on ovary epithelial CHO-K1 cells and an osteoblast precursor from calvaria MC3T3-E1 cells.
The first treatment scheme resulted in a significant reduction in biofilm's metabolic activity by means of 77% by HCOBc and CHX treatments versus negative control. The total count of 11 and 25 species were decreased by treatment with hydro-carbon-oxo-borate complex and CHX, respectively, compared with the group without treatment (p < 0.05), highlighting a reduction in the levels of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Fusobacterium periodontium. CHX significantly reduced the count of 10 microorganisms compared to the group treated with HCOBc (p < 0.05). HCOBc and CHX significantly decreased the pathogenic red-complex proportion compared with control-treated biofilm, and HCOBc had even a more significant effect on the red complex than CHX had (p ≤ 0.05). For the second treatment scheme, HCOBc complex and CHX significantly decreased 61 and 72% of control biofilms' metabolic activity and the counts of 27 and 26 species, respectively. HCOBc complex did not significantly affect the proportions of formed biofilms, while CHX significantly reduced red, orange, and yellow complexes. Both substances exhibited similar cytotoxicity results.
This short communication suggested that the HCOBc complex reduced a smaller number of bacterial species when compared to chlorhexidine during subgingival biofilm formation, but it was better than chlorhexidine in reducing red-complex bacterial proportions. Although HCOBc reduced the mature 6-day-old subgingival multispecies biofilms, it did not modify bacterial complexes' ratios as chlorhexidine did on the biofilms mentioned above. Future in vivo studies are needed to validate these results.
HCOBc complex could be used to reduce red-complex periodontal bacterial proportions.
本研究评估了碳氢氧硼酸络合物 (HCOBc) 对多物种龈下生物膜的代谢活性及其细胞毒性作用。
使用 Calgary 生物膜装置 (CBD) 在 7 天内形成与牙周炎相关的 32 种龈下生物膜。采用两种不同的治疗方案：（1）从第 3 天到第 6 天，每天两次，每次 1 分钟，共 8 次，用 HCOBc、0.12%洗必泰 (CHX) 和阴性对照组（无治疗）治疗；（2）对培养 6 天的生物膜进行 24 小时治疗。形成 7 天后，通过比色法测定生物膜代谢活性，通过 DNA-DNA 杂交测定细菌计数和复合物比例。通过卵巢上皮 CHO-K1 细胞和颅骨 MC3T3-E1 成骨前体细胞的细胞活力 (XTT 测定) 和集落形成存活测定评估两种物质的细胞毒性。
第一种治疗方案导致生物膜代谢活性显著降低，HCOBc 和 CHX 处理组分别比阴性对照组降低 77%。与未治疗组相比，用碳氢氧硼酸络合物和 CHX 处理分别减少了 11 种和 25 种细菌的总计数（p < 0.05），突出了牙龈卟啉单胞菌、福赛斯坦纳菌、中间普雷沃菌和牙周卟啉单胞菌水平的降低。与 HCOBc 治疗组相比，CHX 显著降低了 10 种微生物的计数（p < 0.05）。HCOBc 和 CHX 与对照组处理的生物膜相比，显著降低了致病性红色复合物的比例，而 HCOBc 对红色复合物的影响甚至比 CHX 更显著（p ≤ 0.05）。对于第二种治疗方案，HCOBc 络合物和 CHX 分别显著降低了对照生物膜 61%和 72%的代谢活性和 27 种和 26 种细菌的数量。HCOBc 络合物对形成生物膜的比例没有显著影响，而 CHX 显著降低了红色、橙色和黄色复合物。两种物质均表现出相似的细胞毒性结果。
本简短通讯表明，在龈下生物膜形成过程中，HCOBc 络合物与洗必泰相比减少了较少数量的细菌种类，但在降低红色复合物细菌比例方面优于洗必泰。尽管 HCOBc 减少了成熟的 6 天龄龈下多物种生物膜，但它并没有像洗必泰那样改变生物膜上细菌复合物的比例。需要进行未来的体内研究来验证这些结果。
HCOBc 络合物可用于降低牙周红色细菌复合物的比例。
