Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China.
Int J Nanomedicine. 2021 Nov 16;16:7623-7637. doi: 10.2147/IJN.S335549. eCollection 2021.
This study investigated the effects of mineralizing film consisting of hydroxypropyl methylcellulose (HPMC) and amorphous fluorinated calcium phosphate (AFCP) nanoparticles on enamel white spot lesions (WSLs).
The AFCP nanoparticles and mineralizing film were prepared via nanoprecipitation and solvent evaporation, respectively. They were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), inductively coupled plasma atomic emission spectrometry (ICP-AES), and fluoride ion selective electrode. Thirty-two human enamel slices (4 mm × 4 mm × 1.5 mm) were highly polished and randomly assigned to four groups: negative control (no treatment); pure HPMC film; mineralizing film; GC Tooth Mousse Plus (contains 10% CPP-ACP and 0.2% NaF). Subsequently, samples were challenged by a modified pH-cycling and characterized by color measurement, Micro-CT, SEM/EDX, and nanoindentation.
The mineralizing film could sustain release of Ca, P and F ions over 24 h and maintain AFCP nanoparticles in metastable state over 8~12 h. During 4 weeks of pH cycling, the mineralizing film group exhibited least color change (∆E), mineral loss and lesion depth (120 ± 10 µm) among four groups ( < 0.05). SEM findings revealed that the porosities among enamel crystals increased in negative control and pure HPMC film groups after pH cycling, whereas in mineralizing film group, the original microstructure of enamel was well conserved and mineral deposits were detected between enamel prisms. Mineralizing film group demonstrated a least reduction of nanomechanical properties such as elastic modulus of 77.02 ± 6.84 GPa and hardness of 3.62 ± 0.57 GPa ( < 0.05).
The mineralizing film might be a promising strategy for prevention and management of WSLs via inhibiting enamel demineralization and promoting enamel remineralization.
本研究旨在探讨由羟丙基甲基纤维素（HPMC）和无定形氟化钙磷（AFCP）纳米粒子组成的矿化膜对釉质白斑（WSL）的影响。
通过纳米沉淀和溶剂蒸发分别制备 AFCP 纳米粒子和矿化膜。采用傅里叶变换红外光谱（FTIR）、X 射线粉末衍射（XRD）、透射电子显微镜（TEM）、选区电子衍射（SAED）、扫描电子显微镜（SEM）、能谱（EDX）、电感耦合等离子体原子发射光谱（ICP-AES）和氟离子选择电极对其进行表征。将 32 个人类釉质切片（4mm×4mm×1.5mm）高度抛光并随机分为四组：阴性对照组（无处理）；纯 HPMC 膜组；矿化膜组；GC Tooth Mousse Plus（含 10% CPP-ACP 和 0.2% NaF）组。随后，通过改良的 pH 循环对样本进行挑战，并通过颜色测量、Micro-CT、SEM/EDX 和纳米压痕进行表征。
矿化膜在 24 小时内持续释放 Ca、P 和 F 离子，并在 8-12 小时内保持 AFCP 纳米粒子的亚稳状态。在 4 周的 pH 循环中，矿化膜组的颜色变化（∆E）、矿物质损失和病变深度（120±10μm）最小（<0.05）。SEM 结果显示，在 pH 循环后，阴性对照组和纯 HPMC 膜组釉质晶体之间的孔隙增加，而在矿化膜组中，釉质的原始微观结构得以很好地保留，并在釉柱之间检测到矿物质沉积。矿化膜组的纳米力学性能（弹性模量 77.02±6.84GPa，硬度 3.62±0.57GPa）降低最少（<0.05）。
矿化膜可能是一种通过抑制釉质脱矿和促进釉质再矿化来预防和管理 WSL 的有前途的策略。
