Objectives

To assess the influence of systematically varying concentrations of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) versus 3% 4-META on the polymerisation kinetics and shrinkage, biaxial flexural strength (BFS) and modulus of remineralising composites.

Methods

Composites were prepared by adding poly(propylene glycol) dimethacrylate (24 wt%), camphorquinone (1 wt%) and MDP (0%, 5%, 10%, 15% and 20 wt%) or 4-META (3%) to urethane dimethacrylate. These were mixed with glass fillers containing 8 wt% monocalcium phosphate and 4 wt% polylysine (powder-liquid ratio of 3:1). Continuous spectral changes, following 20 s light exposure (37 °C), were assessed with an ATR-FTIR to monitor polymerisation kinetics (n = 3). Final extrapolated conversions (D_C,max) were employed to calculate polymerisation shrinkage. BFS and modulus of 24-h dry stored disc specimens (10 × 1 mm; n = 10) were determined using a ball-on-ring jig setup.

Results

Maximum rate of polymerisation and D_C,max increased linearly from 2.5 to 3.5% s⁻¹ and 67 to 83%, respectively, upon increasing MDP from 0 to 20 wt%. Values with 3% 4-META were 2.6% s⁻¹ and 78%. Shrinkage was 3.8 ± 0.3% for all formulations. Raising 4-META or MDP from 0 to 3 versus 5%, respectively, increased strength from 106 to 145 versus 136 MPa. A decreasing trend with higher MDP concentrations was noted. Elastic modulus showed no specific trend upon MDP increase.

Significance

Whilst final conversion levels were enhanced by 3% 4-META or >5% MDP, trends did not correlate with strength. Peak strengths with 3% 4-META or 5% MDP may therefore be due to acidic monomers providing linkage between the hydrophilic, non-silane treated particles and the polymer matrix.

中文翻译：

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不同的 10-甲基丙烯酰氧基癸基磷酸二氢盐 (10-MDP) 水平可提高自粘性再矿化复合材料的聚合动力学和抗弯强度

目标

评估系统变化浓度的 10-甲基丙烯酰氧基癸基磷酸二氢盐 (10-MDP) 与 3% 4-META 对再矿化复合材料的聚合动力学和收缩率、双轴弯曲强度 (BFS) 和模量的影响。

方法

通过添加聚（丙二醇）二甲基丙烯酸酯（24 wt%）、樟脑醌（1 wt%）和 MDP（0%、5%、10%、15% 和 20 wt%）或 4-META（3%）制备复合材料为聚氨酯二甲基丙烯酸酯。这些与含有 8 wt% 磷酸二氢钙和 4 wt% 聚赖氨酸（粉液比为 3:1）的玻璃填料混合。用 ATR-FTIR 评估 20 秒曝光 (37 °C) 后的连续光谱变化以监测聚合动力学 ( n = 3)。最终外推转化率 (D _C,max ) 用于计算聚合收缩率。使用球环夹具装置确定24 小时干燥储存圆盘试样 (10 × 1 mm; n = 10) 的 BFS 和模量。

结果

在将 MDP 从 0 wt% 增加到 20 wt% 时，最大聚合速率和 DC _,max分别从 2.5 到 3.5% s ^{-1和 67 到 83% 线性增加。}3% 4-META 的值为 2.6% s ^-1和 78%。所有配方的收缩率为 3.8 ± 0.3%。分别将 4-META 或 MDP 从 0 提高到 3 与 5%，强度从 106 增加到 145 与 136 MPa。注意到随着 MDP 浓度的增加呈下降趋势。弹性模量在 MDP 增加时没有表现出特定的趋势。

意义

虽然最终转化水平提高了 3% 4-META 或 >5% MDP，但趋势与强度无关。因此，3% 4-META 或 5% MDP 的峰值强度可能是由于酸性单体在亲水性、非硅烷处理的颗粒和聚合物基质之间提供了连接。