目的:研究两种市售次氯酸(HClO)产品在模拟临床条件下的理化性质和灭菌效果的稳定性。并评价HClO对口腔软硬组织和细胞的相容性。
方法:制备不同生产工艺的HClO溶液样品,在模拟临床条件下(20-25℃避光,每天打开盖子5分钟),包括游离的有效氯,氧化还原电位和pH。通过悬液定量杀菌试验,绘制了HClO溶液的抗菌浓度曲线,从而校正消毒剂的抗菌能力随贮存过程中有效氯含量的降低而变化。纸浆,将舌头和牙本质浸入PBS中,100ppmHClO,200ppmHClO和3%NaClO。采用称重法和显微硬度试验评价对软硬组织的影响。HClO的毒性作用,通过CCK-8细胞毒性测定确定NaClO及其10倍稀释剂对人牙龈成纤维细胞的作用。使用GraphPadPRIS8.0软件分析数据。
结果:在模拟条件下,HClO溶液的游离有效氯(FAC)随时间衰减,并且在1个月内衰减程度小于20ppm。浓度衰减后各HClO样品的杀菌效力仍高于5log。HClO对软组织和硬组织无明显溶解和破坏(P>0.05).HClO对人牙龈成纤维细胞(HGFC)的细胞活力大于80%,显著高于3%NaClO(P<0.001)。
结论:HClO溶液的杀菌效果和稳定性能满足临床需要,具有较低的细胞毒性和较好的组织相容性。有望成为活髓保存和牙髓再生领域安全高效的消毒产品。
OBJECTIVE: To study the stability of physicochemical properties and sterilizing effect about two commercially available hypochlorous acid (HClO) products under simulated clinical conditions, and to evaluate the compatibility of HClO on soft and hard tissues and cells in oral cavity.
METHODS: Samples of HClO solution with different production processes were prepared, to detect the changes of physicochemical indexes of each sample over time under simulated clinical conditions (shielded from light at 20-25 ℃, open the cover for 5 minutes every day), including free available chlorine, oxidation-reduction potential and pH. Through suspension quantitative germicidal test, the antibiosis-concentration curve of HClO solution was made, so as to calibrate the change of antibacterial ability of disinfectant with the decrease of available chlorine content during storage. Pulp, tongue and dentine were immersed in PBS, 100 ppm HClO, 200 ppm HClO and 3% NaClO. The influence on soft and hard tissues was evaluated by weighing method and microhardness test. The toxic effects of HClO, NaClO and their 10-fold diluent on human gingival fibroblasts were determined by CCK-8 cytotoxicity assay. GraphPad PRIS 8.0 software was used to analyze the data.
RESULTS: Under simulated conditions, the free available chlorine (FAC) of HClO solution decayed with time, and the attenuation degree was less than 20 ppm within 1 month. The bactericidal effect of each HClO sample was still higher than 5log after concentration decay. There was no obvious dissolution and destruction to soft and hard tissues for HClO(P>0.05). The cell viability of HClO to human gingival fibroblast cells (HGFC) was greater than 80%, which was much higher than 3% NaClO (P<0.001).
CONCLUSIONS: The bactericidal effect and stability of HClO solution can meet clinical needs, which has low cytotoxicity and good histocompatibility. It is expected to become a safe and efficient disinfection product in the field of living pulp preservation and dental pulp regeneration.