Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Int Orthod. 2024 Mar;22(1):100836. doi: 10.1016/j.ortho.2023.100836. Epub 2023 Dec 21.
Fixed appliances used in orthodontic treatment are accompanied by some drawbacks, including the development of white spots or enamel demineralization in the vicinity of the brackets and bonding failures. This study aims to evaluate the effect of combining different wt.% of Emodin nanoparticles (ENPs) with orthodontic adhesives to attain adhesives with improved antimicrobial and mechanical properties.
ENPs were synthesized and added to orthodontic composite at different concentrations (0.5%, 1%, and 2%). The distribution of ENPs within the composite was evaluated using a field emission scanning electron microscope (FESEM). A total of 216 disks were prepared, with 144 subjected to an eluted components test, 36 used for disk agar diffusion (DAD) test, and 36 for biofilm inhibition test. These tests aimed to assess the antimicrobial activity of the composites against Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans. Additionally, the bond strength between stainless-steel brackets and teeth was evaluated using the shear bond strength (SBS) test, and the adhesive remnant index (ARI) score was determined. One-way analysis of variance and Kruskal-Wallis test were used to analyse the SBS and ARI, respectively. For pairwise group comparison concerning the biofilm inhibition, DAD, and eluted components tests, the Tamhane and Games-Howell tests for data with unequal variances and the post-hoc Tukey's HSD and Scheffe tests for data with equal variances were used.
The FESEM results confirmed the synthesis and even distribution of ENPs in the composite. Only the 2% group showed significant biofilm inhibition against all microorganisms studied (P<0.05). The DAD test revealed that a 1% concentration of ENPs is sufficient to inhibit growth for all microorganisms. The eluted components test demonstrated that the 2% concentration of ENPs performed significantly better against S. mutans compared to the control group (P<0.05). The highest mean SBS was observed with the 0.5% ENP concentration, while no significant differences in SBS and ARI were found among the groups (P>0.05).
This in vitro study showed that the 2% concentration of ENP produced significantly improved antimicrobial activity without adversely affecting SBS and ARI score. This would support the addition of 2% ENP to orthodontic adhesives.
正畸治疗中使用的固定矫治器存在一些缺点,包括托槽附近出现白点或釉质脱矿以及粘结失败。本研究旨在评估将不同重量百分比的大黄素纳米颗粒(ENPs)与正畸粘结剂结合使用,以获得具有改善的抗菌和机械性能的粘结剂。
合成 ENPs 并以不同浓度(0.5%、1%和 2%)添加到正畸复合材料中。使用场发射扫描电子显微镜(FESEM)评估 ENPs 在复合材料中的分布。共制备 216 个圆盘,其中 144 个进行洗脱成分测试,36 个用于圆盘琼脂扩散(DAD)测试,36 个用于生物膜抑制测试。这些测试旨在评估复合材料对变形链球菌、嗜酸乳杆菌和白色念珠菌的抗菌活性。此外,使用剪切粘结强度(SBS)测试评估不锈钢托槽与牙齿之间的粘结强度,并用粘结残留指数(ARI)评分进行评估。使用单因素方差分析和 Kruskal-Wallis 检验分别分析 SBS 和 ARI。对于生物膜抑制、DAD 和洗脱成分测试的组间比较,对于具有不等方差的数据使用 Tamhane 和 Games-Howell 检验,对于具有相等方差的数据使用事后 Tukey 的 HSD 和 Scheffe 检验。
FESEM 结果证实了 ENPs 的合成和复合材料中的均匀分布。只有 2%组对所有研究的微生物均表现出显著的生物膜抑制作用(P<0.05)。DAD 测试表明,1%浓度的 ENPs 足以抑制所有微生物的生长。洗脱成分测试表明,与对照组相比,2%浓度的 ENPs 对变形链球菌的抑制作用明显更好(P<0.05)。观察到最高的平均 SBS 是在 0.5%ENP 浓度下,而各组之间的 SBS 和 ARI 没有显著差异(P>0.05)。
这项体外研究表明,2%浓度的 ENP 产生了显著改善的抗菌活性,而不会对 SBS 和 ARI 评分产生不利影响。这将支持在正畸粘结剂中添加 2%的 ENP。