Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China; Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21021, USA.
Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21021, USA.
Dent Mater. 2021 Jun;37(6):1009-1019. doi: 10.1016/j.dental.2021.03.020. Epub 2021 Apr 18.
Fluoride (F)-releasing restoratives typically are either weak mechanically or release only low levels of F ions. The objectives of this study were to: (1) develop a novel photo-cured nanocomposite with strong mechanical properties and high levels of sustained F ion release via a two-step "co-precipitation + spray-drying" technique to synthesize CaF nanoparticles (nCaF); and (2) investigate the effect of spray-drying treatment after co-precipitation of nCaF on mechanical properties and F ion release of composite.
Two types of CaF particles were synthesized: A co-precipitation method yielded CaFcp; "co-precipitation + spray-drying" yielded nCaFcpsd. Composites were fabricated with fillers of: (1) 0% CaF + 70% glass; (2) 10% CaFcp + 60% glass; (3) 15% CaFcp + 55% glass; (4) 20% CaFcp + 50% glass; (5) 10% nCaFcpsd + 60% glass; (6) 15% nCaFcpsd + 55% glass; and (7) 20% nCaFcpsd + 50% glass. A commercial F-releasing nanocomposite served as control.
The nCaFcpsd had much smaller particle size (median = 32 nm) and narrower distribution (22-57 nm) than CaFcp (median = 5.25 μm, 162 nm-67 μm). The composite containing nCaFcpsd had greater flowability, flexural strength, elastic modulus and hardness than CaFcp composite and commercial control composite. At 84-day immersion in water, the nanocomposites containing 20% nCaFcpsd had 65 times higher cumulative F release, and 77 times greater long-term F-release rate, than commercial control.
A novel two-step "co-precipitation + spray-drying" technique of synthesizing nCaF was developed. The photo-cured nanocomposite containing 20% nCaFcpsd possessed strong mechanical properties and excellent long-term F-release ability, and hence is promising for dental restoration applications to inhibit secondary caries.
释放氟化物（F）的修复体通常机械性能较弱或仅释放低水平的 F 离子。本研究的目的是：（1）通过两步“共沉淀+喷雾干燥”技术开发一种新型光固化纳米复合材料，该技术具有高强度机械性能和高持续 F 离子释放水平，以合成 CaF 纳米颗粒（nCaF）；（2）研究共沉淀后喷雾干燥处理对复合材料机械性能和 F 离子释放的影响。
合成了两种类型的 CaF 颗粒：共沉淀法得到 CaFcp；“共沉淀+喷雾干燥”得到 nCaFcpsd。用以下填料制备复合材料：（1）0% CaF + 70%玻璃；（2）10% CaFcp + 60%玻璃；（3）15% CaFcp + 55%玻璃；（4）20% CaFcp + 50%玻璃；（5）10% nCaFcpsd + 60%玻璃；（6）15% nCaFcpsd + 55%玻璃；（7）20% nCaFcpsd + 50%玻璃。商业 F 释放纳米复合材料作为对照。
nCaFcpsd 的粒径（中位数=32nm）和分布（22-57nm）明显小于 CaFcp（中位数=5.25μm，162nm-67μm）。含 nCaFcpsd 的复合材料具有更高的流动性、抗弯强度、弹性模量和硬度，优于 CaFcp 复合材料和商业对照复合材料。在水中浸泡 84 天，含 20%nCaFcpsd 的纳米复合材料的累积 F 释放量是商业对照的 65 倍，长期 F 释放率是商业对照的 77 倍。
开发了一种新型两步“共沉淀+喷雾干燥”合成 nCaF 的技术。含 20%nCaFcpsd 的光固化纳米复合材料具有高强度机械性能和优异的长期 F 释放能力，有望用于牙科修复体抑制继发龋。
