Department of Pediatric and Orthodontic Sciences, College of Dentistry, King Khalid University, Abha, Saudi Arabia.
Department of Oral and Maxillofacial Surgery, College of Dentistry, King Khalid University, Abha, Saudi Arabia.
Microsc Res Tech. 2022 Mar;85(3):996-1004. doi: 10.1002/jemt.23968. Epub 2021 Oct 30.
This study aims to evaluate the feasibility of chlorhexidine (CHX)-loaded poly-L-glycolic acid (PLGA) nanoparticles as a modifier of a commercial orthodontic adhesive via the assessment of physicochemical, biological, and mechanical properties at tooth-bracket interface. CHX-loaded PLGA nanoparticles were synthesized using double emulsion-solvent evaporation method and characterized using transmission electron microscopy and Raman analysis. CHX-loaded PLGA nanoparticles in Transbond XT orthodontic adhesive were prepared using two different concentrations of the CHX (25 and 50%) and characterized for degree of conversion (DC), antimicrobial, and cytotoxicity testing. Bonded specimens were tested for shear bond strength (SBS) and adhesive remnant index (ARI) at tooth-bracket interface. The synthesized PLGA nanoparticles averaged between 60 and 80 nm in size. After loading CHX inside PLGA nanoparticles, the morphology of the PLGA nanoparticles was considerably changed. Orthodontic bracket bonded with 25% CHX-loaded PLGA-modified adhesive demonstrated DC scores similar to control group. Both 25 and 50% CHX-loaded PLGA-modified adhesive specimens showed higher antibacterial activity against S. mutans compared to control group. The least mean SBS values were exhibited by 50% CHX-loaded PLGA-modified adhesive samples, while a statistically significant difference was observed in the mean ARI values among all study groups at all-time points (p = .018). This study indicates that the addition of CHX-loaded PLGA nanoparticles in Transbond XT achieved stable bonds with enhanced antimicrobial and mechanical properties.
本研究旨在通过评估牙托界面的物理化学、生物学和机械性能，评估载氯己定（CHX）的聚-L-丙交酯（PLGA）纳米粒子作为商业正畸胶粘剂改性剂的可行性。采用双乳液-溶剂蒸发法合成 CHX 负载的 PLGA 纳米粒子，并通过透射电子显微镜和拉曼分析进行表征。采用两种不同浓度的 CHX（25%和 50%）将 CHX 负载的 PLGA 纳米粒子制备在 Transbond XT 正畸胶中，并对转化率（DC）、抗菌和细胞毒性进行测试。在牙托界面测试粘结试件的剪切粘结强度（SBS）和粘结残留指数（ARI）。合成的 PLGA 纳米粒子平均粒径在 60-80nm 之间。在将 CHX 负载到 PLGA 纳米粒子内部后，PLGA 纳米粒子的形态发生了很大的变化。用 25%载有 CHX 的 PLGA 改性胶粘合的正畸托槽的 DC 评分与对照组相似。25%和 50%载有 CHX 的 PLGA 改性胶标本对变形链球菌的抗菌活性均高于对照组。50%载有 CHX 的 PLGA 改性胶样本的平均 SBS 值最低，而所有研究组在所有时间点的平均 ARI 值均存在统计学差异（p=0.018）。本研究表明，在 Transbond XT 中添加载有 CHX 的 PLGA 纳米粒子可获得稳定的结合，并具有增强的抗菌和机械性能。
