Liang Xiaoxu, Zhou Dandan, Yu Biao, Zhong Hai-Jing, He Jingwei
School of Arts and Sciences, Guangzhou Maritime University, Guangzhou, 510725, China.
School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, China.
J Mech Behav Biomed Mater. 2025 Dec;172:107177. doi: 10.1016/j.jmbbm.2025.107177. Epub 2025 Aug 28.
Glass ionomer cements (GICs) suffer from mechanical limitations due to rigid intermolecular hydrogen bonding in polyalkenoic acid (PCA) that impedes ionic cross-linking during setting. This study examined how molecular weight and solution concentration of modified polyalkenoic acid (PCA) containing 3-butenoic acid (VA) spacers at 8 mol% concentration (PCA-VA-8) influence comprehensive GIC performance.
PCA-VA-8 polymers with varying molecular weights (5.49 × 10 to 15.57 × 10) were synthesized via free radical copolymerization of acrylic acid, itaconic acid, and 3-butenoic acid by controlling initiator dosage. Experimental GICs were prepared using different PCA-VA-8 concentrations (40-60 wt%) and powder-to-liquid ratios (3.2:1 to 4.0:1). Mechanical properties were evaluated according to ISO 9917-1:2007 standards, while water sorption, solubility, aging resistance, and fluoride release were assessed over 4-week immersion periods.
The optimal formulation (molecular weight ≈8 × 10, 50 wt% concentration, 3.6:1 powder-to-liquid ratio) achieved enhanced mechanical properties: flexural strength 54.14 ± 5.29 MPa, flexural modulus 19.00 ± 1.06 GPa, and compressive strength 221.35 ± 17.06 MPa (p < 0.05). This formulation showed 33 %-63 % higher flexural strength than commercial Fuji IX-GIC throughout 4-week water aging while maintaining excellent dimensional stability. Water sorption was reduced by 18 %-22 % during initial weeks compared to commercial materials, with solubility remaining comparable to controls (p > 0.05). Fluoride release analysis revealed an initial burst release of 4.1 μg/mL on day 1, followed by stabilization at 0.6-0.9 μg/mL from day 4 onward. Although lower than the initial release of commercial Fuji IX-GIC (6.2 μg/mL), the sustained fluoride levels remained above the therapeutic threshold necessary for remineralization and caries prevention.
VA-modified PCA enhances GIC mechanical properties through improved polymer chain flexibility while maintaining clinical requirements for water resistance and fluoride release, representing a promising advancement for next-generation restorative applications.
由于聚烯酸（PCA）中存在刚性分子间氢键，阻碍了凝固过程中的离子交联，玻璃离子水门汀（GICs）存在机械性能限制。本研究考察了含8摩尔%浓度3-丁烯酸（VA）间隔基的改性聚烯酸（PCA-VA-8）的分子量和溶液浓度如何影响GIC的综合性能。
通过控制引发剂用量，使丙烯酸、衣康酸和3-丁烯酸进行自由基共聚，合成了不同分子量（5.49×10至15.57×10）的PCA-VA-8聚合物。使用不同的PCA-VA-8浓度（40-60 wt%）和粉液比（3.2:1至4.0:1）制备实验性GIC。根据ISO 9917-1:2007标准评估机械性能，同时在4周浸泡期内评估吸水率、溶解度、耐老化性和氟释放。
最佳配方（分子量≈8×10，浓度50 wt%，粉液比3.6:1）实现了机械性能增强：弯曲强度54.14±5.29 MPa，弯曲模量19.00±1.06 GPa，抗压强度221.35±17.06 MPa（p<0.05）。在4周水老化过程中，该配方的弯曲强度比市售富士IX-GIC高33%-63%，同时保持了优异的尺寸稳定性。与市售材料相比，最初几周的吸水率降低了18%-22%，溶解度与对照相当（p>0.05）。氟释放分析显示，第1天初始突发释放量为4.1μg/mL，从第4天起稳定在0.6-0.9μg/mL。虽然低于市售富士IX-GIC的初始释放量（6.2μg/mL），但持续的氟水平仍高于再矿化和预防龋齿所需的治疗阈值。
VA改性的PCA通过改善聚合物链柔韧性提高了GIC的机械性能，同时保持了耐水性和氟释放的临床要求，代表了下一代修复应用的有前景的进展。
