Ilie Nicoleta
Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig Maximilians University, Munich Goethestr. 70, D-80336 Munich, Germany.
Materials (Basel). 2021 Mar 16;14(6):1452. doi: 10.3390/ma14061452.
The longevity of indirect restorations is primarily determined by the appropriate selection of the luting material. The function of a luting material is to seal the restoration and hold it in place for the time required for service. The mechanical behavior of luting materials and in particular their aging behavior, therefore, play a decisive role. The study provides a comparative analysis of the static and dynamic mechanical behavior of the most commonly used luting material categories-zinc phosphate cement, glass-ionomer cement, resin-modified glass-ionomer cement, resin-based composites, and self-adhesive resin-based composites-and their aging behavior. It also takes into account that luting materials are viscoelastic materials, i.e., materials that respond to external loading in a way that lies between an elastic solid and a viscous liquid. Flexural strength and modulus were determined in a three-point bending test followed by fractography analysis. The quasi-static and viscoelastic behavior was analyzed by a depth-sensing indentation test provided with a dynamic mechanical analysis (DMA) module at 20 different frequencies (1-50 Hz). The fracture toughness was evaluated in a notchless triangular prism (NTP) test. Material type exhibits the strongest influence on all measured properties, while the effect of aging becomes more evident in the material reliability. The variation of the viscoelastic parameters with aging reflects cement maturation or polymer plasticization.
间接修复体的使用寿命主要取决于粘结材料的恰当选择。粘结材料的作用是密封修复体，并在其使用所需的时间内将其固定在位。因此，粘结材料的力学行为，尤其是它们的老化行为，起着决定性作用。本研究对最常用的粘结材料类别——磷酸锌水门汀、玻璃离子水门汀、树脂改性玻璃离子水门汀、树脂基复合材料和自粘结树脂基复合材料——的静态和动态力学行为及其老化行为进行了比较分析。研究还考虑到粘结材料是粘弹性材料，即对外部载荷的响应方式介于弹性固体和粘性液体之间的材料。通过三点弯曲试验测定弯曲强度和模量，随后进行断口分析。通过配备动态力学分析（DMA）模块的深度传感压痕试验，在20个不同频率（1 - 50Hz）下分析准静态和粘弹性行为。在无缺口三棱柱（NTP）试验中评估断裂韧性。材料类型对所有测量性能的影响最为显著，而老化对材料可靠性的影响则更为明显。粘弹性参数随老化的变化反映了水门汀的成熟或聚合物的塑化。
