Samiei M, Ghasemi N, Divband B, Balaei E, Hosien Soroush Barhaghi M, Divband A
Department of Endodontics, Dental Faculty, Tabriz University (Medical Sciences), Tabriz, Iran -
Minerva Stomatol. 2015 Dec;64(6):275-81.
The aim of the present study was to compare the antibacterial properties of PLGA polymer containing ZnO, Ag and ZnO/Ag nanoparticles with those of 2.5% NaOCl in root canals contaminated with Enterococcus faecalis.
A total of 100 maxillary central incisors were selected. After the crowns were removed to achieve 12-mm-length roots, the root canals were prepared with RaCe rotary system. The samples were sterilized; then 200 µL of E. faecalis suspension (ATCC 29212) was placed in each root canal. The samples were divided into 5 groups based on the antibacterial agent used. Group 1 served as the control group. In group 2 the polymer suspension containing ZnO nanoparticles, in group 3 the polymer solution containing ZnO/Ag nanoparticles, in group 4 the polymer solution containing Ag nanoparticles and in group 5, 2.5% NaOCl were used. After 24 hours, a solution was prepared using dentin chips from each root canal and placed on agar plates, followed by colony-forming units (CFU) count determination. Means ± standard deviations were calculated and Kruskal-Wallis test was used to evaluate the antibacterial properties of different irrigation agents. Mann-Whitney U test was used for two-by-two comparisons of the groups, with the level of significance being set at 0.05.
The maximum and minimum CFU counts were observed in the control and NaOCl groups, respectively. In the polymer groups, the maximum and minimum CFU counts were observed in the Ag and ZnO/Ag groups, respectively. There were significant differences in CFU counts between the study groups after application of irrigation solutions (P<0.05). Two-by-two comparisons of the groups using Mann-Whitney U test showed significant differences between all the study groups (P<0.05), except for groups ZnO and Ag (P=0.7).
Sodium hypochlorite solution was more effective than copolymer containing nanoparticles and of all the tested nanoparticles; ZnO/Ag nanoparticles exhibited the highest antibacterial activity.
本研究旨在比较含氧化锌（ZnO）、银（Ag）及ZnO/Ag纳米颗粒的聚乳酸-羟基乙酸共聚物（PLGA）聚合物与2.5%次氯酸钠（NaOCl）对被粪肠球菌污染的根管的抗菌性能。
共选取100颗上颌中切牙。去除牙冠使牙根长度达到12毫米后，用RaCe旋转系统预备根管。将样本灭菌；然后在每个根管中放置200微升粪肠球菌悬液（ATCC 29212）。根据所使用的抗菌剂将样本分为5组。第1组作为对照组。第2组使用含ZnO纳米颗粒的聚合物悬液，第3组使用含ZnO/Ag纳米颗粒的聚合物溶液，第4组使用含Ag纳米颗粒的聚合物溶液，第5组使用2.5% NaOCl。24小时后，使用来自每个根管的牙本质碎屑制备溶液并置于琼脂平板上，随后进行菌落形成单位（CFU）计数测定。计算均值±标准差，并使用Kruskal-Wallis检验评估不同冲洗剂的抗菌性能。使用Mann-Whitney U检验对各组进行两两比较，显著性水平设定为0.05。
对照组和NaOCl组分别观察到最高和最低的CFU计数。在聚合物组中，Ag组和ZnO/Ag组分别观察到最高和最低的CFU计数。应用冲洗液后，各研究组之间的CFU计数存在显著差异（P<0.05）。使用Mann-Whitney U检验对各组进行两两比较显示，除ZnO组和Ag组外（P = 0.7），所有研究组之间均存在显著差异（P<0.05）。
次氯酸钠溶液比含纳米颗粒的共聚物更有效，并且在所有测试的纳米颗粒中，ZnO/Ag纳米颗粒表现出最高的抗菌活性。
