Photopolymerization volumetric shrinkage in densely monolith dental restorative composites is characterized at the example of ЭCTA-3^® composites, employing positron annihilation lifetime (PAL) spectroscopy within unconstrained × 3-term analysis applied to reconstructed PAL spectra. The governing process in these composites is identified as mixed positron-Ps trapping, where Ps-decaying originates from free-volume holes in polymer matrix, while free positron trapping occurs in interfacial holes between preferential filler nanoparticles and surrounded polymer matrix. Meaningful phenomenological description of this photopolymerization process is developed at the basis of semi-empirical model exploring the × 3- × 2-CDA (coupling decomposition algorithm). Within this approach, it is shown that under light-curing polymerization, strong monolithization of agglomerated filler particles occurs in these nanocomposites caused by photoinduced disappearing of Ps-decaying holes due to cross-linking of structural chains, mainly in “purely” polymer matrix.

光聚合体积收缩在密集整料牙齿修复复合的特征在于在ЭCTA-3的示例^®在无约束×3项分析中采用正电子an没寿命（PAL）光谱对复合材料进行分析，然后将其应用于重建的PAL光谱。这些复合材料的控制过程被确定为混合正电子-Ps捕集，其中Ps的衰减源自聚合物基质中的自由体积孔，而自由正电子的捕集发生在优先填料纳米颗粒和周围的聚合物基质之间的界面孔中。在探索×3-×2-CDA（耦合分解算法）的半经验模型的基础上，开发了这种光聚合过程的有意义的现象学描述。在这种方法中，表明在光固化聚合作用下，